This was a very interesting read. Thanks for taking the time to explain this so carefully. I know the above is a discussion about autolysis and many of my questions have already been answered in the comments here. But, I've got three questions that at least partially relate to this that I'd be grateful if you took the time to answer.
Q1: Why does bassinage work? In my experience it makes a dough of a said hydration more elastic than a dough at the same hydration that wasn't mixed using bassinage, assuming total mixing time is the same. As I understand from above the shear flow from the mechanical mixing helps to unfold the large hydrophilic glutenin molecules so as to increase their surface area and ad/absorb more water. At a certain point in the mix, after a long slow mix and a few minutes on 2nd, the dough looks very elastic to me, balls up around the hook, and I add the remaining water. What, on the macromolecular level, happens as this extra water is added in 2nd speed?
Q2: What does it mean on the same scale level, that a dough is over-developed, rips, loses its elasticity, becomes wet and sticky? Does this have to do with water distribution between the gluten, starch, pentosans and the aqueous phase?
Q3: As we include salt from the start of the mix, rather than delaying its addition until the very end (which I've done for years), doesn't it mean it "uses" a part of the water in the aqueous phase from the start and thus leave less water for the gluten parts to ad/absorb? I've noticed doughs develop faster from the onset if salt goes in at the start, but that they also more easily get over-mixed - tear apart. Please elaborate if you have the time.
This is great, Ian. I've done an autolyse on my doughs for years, since I was trained in part by my friend James MacGuire, who was a friend of Calvel's (and his English translator). But I've recently ditched it and haven't really noticed any negative consequences and think you are correct.
A few questions:
- Do you see any benefit to a "hydration" rest before mixing when working with high-extraction or whole grain flours, as a means to let the bran hydrate? I have found that even a short rest can result in a less shaggy dough and what seems like more efficient mixing. I suppose this might work similarly with or without the salt and/or preferments, so it could still be done in the absence of a strict autolyse.
- I've found that holding back the salt is helpful for mixing efficiency when hand mixing—it helps to let the flour hydrate evenly and avoid clumping. Even if I am not doing an autolyse, I'll often hold back the salt until I've mixed the flour and water, then immediately add it. Do you see any downsides to doing this, in terms of ultimate dough strength?
- Is saying that an autolyse compromises dough elasticity the same as saying that it *increases* extensibility? If so, that might be a reason to do it, if increasing extensibility were the goal. (This was a common refrain on pizza making forums for years, that adding a brief autolyse made dough balls more easy to stretch.)
Also: glad you are back posting here, will mention it to my readers soon.
Remember my framework for evaluating whether or not you should do something. Does it bring you joy? Does it help you achieve your desired end result? If yes to both, do it.
Q1. My above comments pertain to low-extraction flours. Once you throw the baby and the bath water in, all bets are off. That’s another way of saying, the phase-separation and water-distribution characteristics of whole-grain or high-extraction flours differ greatly compared to white flour. If you find a “rest” period, in which the larger constituents (bran and cell-wall polysaccharides) hydrate, helps, go for it. I assume you’re only referring to mixing in smaller quantities and/or hand-mixing. It should result in a softer dough, albeit one with an even greater decrease in elasticity values. Decreases in elasticity value also correspond to decreases in final-product volume.
Q2. My guess is the answer is flour-dependent. New-world flours are strong. Like USSR competing in the ‘80s Olympics strong. The quantity and size of the largest glutenins in such flours means they require more energy input, both in terms of rate and total amount, relative to softer and/or weaker flours in order to ensure those large glutenins are able to participate in gel-network formation. The fact is, most amateur (and many professional) bakers using stronger, new-world flours do not mix enough to achieve a sufficiently soft dough. They therefore seek other alternatives to “soften,” e.g., increasing hydration, using an extended autolysis, and so on. Salt decreases the quantity of water in the gluten phase and increases gluten protein self-association. I do not believe there are any trade-offs to holding back salt when making bread in small quantities. (In professional settings, I advise against it, only as one less thing to forget. This matters in high-throughput settings. Salt can then be pre-weighed the day before and included with other dry components that are added at the beginning of the mixing process. Remember my other rule: I don’t like to think when I bake. This allows me to focus on what matters, minimising variation of process and hence product.)
Q3. No, decreasing elasticity values is not equivalent to saying it increases extensibility. Extensibility is its own rheological measure, quantified by two scalar values. The total distance a dough can be stretched before rupture, and the energy input at the point of rupture. People focus on the second of these two quantities. “How easy it is to stretch” is not the same as “how far it stretches.” It’s an error to focus on the wrong parameter with considerable downstream consequences on product quality.
In wheat dough products where an elongational process is required, like pizza or baguette, if your product is fighting you, the answer is, almost without exception, never autolyse. Why? Because product volume will suffer. Diminished volume in products requiring elongation impacts final quality much more relative to those products with lower or minimal elongational requirements. Wheat flour products requiring high elongation values are part of a larger class of products that have high ratios of surface area to interior volume (SA:V). High SA:V products include ciabatta, flat breads, bread sticks, baguettes, crackers, cookies, biscuits, many styles of cake or quick breads (scones or drop biscuits), and so on.
This class of products all display horizontality (in the X- and Z-axes), called “spread” in cookies. You’ll notice another commonality: The biggest “faults” perceived by consumers in such products are textural, such as “toughness” or “shortness,’’ which results from incorrect choices made in process, raw material, or formulation. The most important parameter to combat product toughness in this class of products is to maximise final volume, followed by ensuring all variables (raw material, formulation, and processing) conform to this goal.
An autolysis step does not fall into the solution types that maximise product volume. (Remember, in biologically-leavened wheat-flour products, the maximum volume achievable is directly determined by maximum elasticity values that are attainable. The latter parameter, in turn, is directly determined by the total surface area of “gluten” proteins, particularly the largest-sized glutenins.) Further, an autolysis step will have other trade-offs in such products, such as “shortness.”
The best solution in such products is almost always in choosing the right flour. (“More than 90% of making a great baguette involves simply choosing the correct flour.”) This is why so many new-world pizzamakers import Italian flours like Caputo (though marketing plays a huge role, too). I see this in Australia: Pizza joints choose Caputo without exploring the local option space.
If the correct flour has been chosen, then the baker or pizzamaker should then look at the other parameters that most impact volume. In this case, that variable is (degree of) fermentation followed by formulation.
Lastly, it's great you now James. He's a figure I've always greatly admired but have never met.
Not sure if you are taking requests for future posts here, but I'd love to see you address this topic in more detail:
"The fact is, most amateur (and many professional) bakers using stronger, new-world flours do not mix enough to achieve a sufficiently soft dough."
I've seen you mention this idea many times—that extended mixing increases dough softness—and I'd love to know what "enough" looks like, both in practical terms and in results, especially since most bakers mix to a specific *strength*, and I sense you are talking about something else.
James is a wonderful person, one of my treasured teachers and friends. His health has not been great for the last few years, so he's kept a low profile mostly. His writing—especially his essays for the Art of Eating—are ones I recommend to everyone.
Hi Ian, thanks for the in-depth knowledge sharing. This is the longest answer I ever get from asking a question. I have to say it’s all very technical, I managed to grasp some ideas but I cannot say I fully understand. I probably need to go over it a few more times.
I have a question regarding your advice to make a no-knead bread instead. It greatly confuses me. If hydrating flours (autolysis) alone doesn’t help develop gluten, how does a no-knead bread develop its gluten? There is no kneading/folding whatsoever.
Let me be more specific with my question. You mentioned in one of the comments above “You need to plasticise, liquidise and break up the largest glutenin particles so they can ad/absorb water before solvent quality is altered.”, so when making a no-knead bread, which stage in the process is the large glutenin particles get break up and allowed to absorb water, don’t you just combine the ingredients and leave to bulk in a no-knead bread? If glutenins cannot fully absorb all the water they need before solvent quality degrades, then how is a no-knead bread different from performing an autolysis? Please shed some lights when you have the time. Thank you so much!
I never claimed the no-knead bread process results in a fully-developed dough, and that’s the point. If, as a baker, you’re willing to use an autolysis step, and do more work for “less” results (diminished volume, decreased dough development), why not just make no-knead bread? It’ll give you comparable results for less work.
Hi Ian, I want to thank you first of all for all the knowledge you shared on Instagram in these years. I cannot remember an instagram story of yours I did not take notes about.
For what I understood, shear during mixing is thus basically responsible for protein unfolding, especially the biggest ones, and unfolded proteins wet more easily since they have more "wetted microstates" than folded ones. Is this mechanism is somewhat independent of the "solvent quality", since you wrote that polysaccharides wetting happens earlier than protein wetting, or the very purpose of mixing is to "anticipate" protein wetting so that they can compete with polysaccharides for water? I would go for the second since I'm assuming that the amount of water molecules in the dough is order of magnitudes more than the average number of bindings at every time, otherwise there would be no water left for yeasts and bacterias. Proteins would always have enough water to saturate all their bindings even in the unfolded state, but without shear flow no fluctuations in reasonable time would break the folded state to let them bind with water.
Should I deduce anyway then that wetting speedup due to shear flow does not apply to polysaccharides since those chains do not have only one microstate?
Also, while I remember the picture of the dispersed polysaccharides phases in the continuous "gluten" phase from your GrAiNz presentation, I don't understand what you mean when you refer to the gel (I must say my knowledge of soft matter is lacking)
Lastly, I would naively say that no-knead is autolysis without mixing next, so I don't understand within this picture you made how dough could develop any structure with no-knead.
I appreciate if you will ever find time to answer my questions, and look forward to the next post!
I believe you’re focusing on the wrong scale of causal determination. Your question presumes we should look at the problem through a water molecule’s eyes. Most food science makes the same error.
If we did adopt the view at the level of electrostatic interactions, then we’d end up with a major paradox: How is it that water doesn’t spill out from a dough all over the floor? After all, there’s barely enough hydrophilic sites in flour biopolymers to cover all of them in a monolayer of water one water molecule thick.
You cannot resolve this puzzle at the level of the hydrogen bond. It’d be like trying to explain why I’m bad at Pac-Man by looking at the CPU’s machine code. There’s simply no determinative causality at that scale.
Don’t think of the problem using microstates. That’s where food scientists designing experiments probing water’s behaviour in food systems get in trouble. They’re probing the wrong space-time scale length. It’s better to think of water as a bulk material described using statistical mechanics.
In condensed, porous material, water’s held in place by pressure differentials, not hydrogen bonds. Free hydrophilic sites may contribute to that overall force differential, but, as you state, it’s far from the whole story. It’s the same mechanism behind why sponges absorb water, or why liquids climb up the inside straws.
I’m not sure where you’re getting the idea that polysaccharide wetting occurs before (or faster than?) protein. I didn’t mention polysaccharides in my post. They certainly play a huge role in this discussion, particularly soluble and insoluble arabinoxylans, due to their much larger size and greater hydrophilicity.
If the pentosans are allowed to hydrate fully before the largest molecular weight glutenins, this shifts the phase-separation threshold with greater gluten network discontinuity due to excluded volume effects and thermodynamic incompatibility.
Shear flow has a substantial impact on all polysaccharide hydration, particularly for pentosans. However, not in the same way as gluten proteins, which are thixotropic. This means that, below their glass-transition temperature and in the presence of sufficient plasticiser (as in dough conditions), they reversibly fluidise. Pentosans don’t do this, as when they participate in irreversible gels. (“Gluten” is a reversible, physical gel stabilised directly and indirectly by non-covalent interactions. Add shear and plasticiser, and the gel becomes fluid. Remove the shear, it becomes solid.)
What determines strength in wheat doughs is the average molecular weight and total concentration of the largest-sized glutenins (or “glutenin macropolymer,” or GMP). A “weak” flour may only contain 0.7% GMP of small size. The average European flour will have 2% of medium molecular size. A very strong flour may contain up to 3.5% of very large size.
In their native state, polysaccharides are 1 to 3 orders of magnitude larger than even the biggest glutenins. This means they have much greater internal surface area to suck water into, and, in the case of pentosans, much greater hydrophilicity.
So, yes, solvent quality does matter. What’s a poor solvent for “gluten” may be a great solvent for pentosans.
You need to plasticise, liquidise and break up the largest glutenin particles so they can ad/absorb water before solvent quality is altered. Because, once the nature of the solvent changes, any “gluten” proteins that are plasticised, hydrated and swollen will participate in gel-network formation, becoming directly or indirectly stabilised by the non-specific interaction "structure" established by the mixing parameters.
Thank you for your reply. I flew over the problem of water spill-out assuming that water diffusion is much slower then the average hydrogen bond lifetime, so that water "get caught back" by a new bond before it manages to spill out. But I'm not familiar enough with the physical quantities at play to tell if this makes sense or not.
But I still have some trouble understanding how the change in solvent work. First, of all, is what we call here solvent what you called dough liquor during your grainz talk? I would say yes since pentosans and starches repel with glutenins and gliadins.
Say we divide the solid content of flour in insoluble pentosans, starch, gluten, and all the rest that goes into dough liquor (as per the centrifugation studies you mentioned at grainz). Do the four groups take the same amount of time to hydrate? I would say no, as you remarked above about fully hydrated pentosans that shift phase separation threshold. But are you talking about soluble pentosans in dough liquor or to insoluble pentosans in the pentosans gel?
My best mental model so far is that gluten phase takes much more time to hydrate than dough liquor to reach equilibrium if I do autolysis. If straight mixing instead, hydrophilic sites in the forming gluten phase are exposed before complete mixing of soluble flour components in water; this means that the "local dough liquor" seen by gluten proteins in its vicinity is more diluted and so more favorable to wet the proteins.
>>Thank you for your reply. I flew over the problem of water spill-out assuming that water diffusion is much slower then the average hydrogen bond lifetime, so that water "get caught back" by a new bond before it manages to spill out. But I'm not familiar enough with the physical quantities at play to tell if this makes sense or not.
Conceptualising the problem at the hydrogen-bond level has little explanatory power. It’s better to model water as a bulk material that exhibits aggregative statistical properties. We can then chunk water into groups. Each ensemble, at the “group” level, is distinct, and associated with different phases, even if, at the level of individual water molecules, any one particular water molecule is promiscuous. I.e., any one water molecule can be anywhere within the system, constrained only by diffusion kinetics.
>>But I still have some trouble understanding how the change in solvent work. First, of all, is what we call here solvent what you called dough liquor during your grainz talk? I would say yes since pentosans and starches repel with glutenins and gliadins.
Yes, the “solvent” is the dilute, remaining aqueous medium dispersed throughout the entire dough system, not the groups of water associated with each phase.
>>Say we divide the solid content of flour in insoluble pentosans, starch, gluten, and all the rest that goes into dough liquor (as per the centrifugation studies you mentioned at grainz). Do the four groups take the same amount of time to hydrate? I would say no, as you remarked above about fully hydrated pentosans that shift phase separation threshold.
No, they do not hydrate at the same rate, BUT continuous shear flow smooths the distribution kinetics, for several reasons. (One of the reasons is that, depending upon shear-flow velocity, the interaction of water molecules with biopolymers can occur at rates faster than would occur during normal passive diffusion. Liquidising and/or increasing biopolymer surface area aids in the smoothing of this distribution.)
>>But are you talking about soluble pentosans in dough liquor or to insoluble pentosans in the pentosans gel?
For the changes in distribution kinetics between higher-extraction flours and refined flours, I was referring to insoluble pentosans, as the pentosan gel phase increases in size.
For changes in solvent quality, I mean soluble pentosans.
>>My best mental model so far is that gluten phase takes much more time to hydrate than dough liquor to reach equilibrium if I do autolysis.
Correct. The soluble dough constituents would diffuse into the dough liquor at a rate greater than all gluten proteins can hydrate. One thing to remember is that the largest-molecular-weight glutenins will NOT fully hydrate if using a non-continuous mixing process, since they remain as large hydrophobic spherical particles. Their full hydration requires depolymerising them (which requires shear flow of a certain velocity and duration), increasing their surface area.
>>If straight mixing instead, hydrophilic sites in the forming gluten phase are exposed before complete mixing of soluble flour components in water; this means that the "local dough liquor" seen by gluten proteins in its vicinity is more diluted and so more favorable to wet the proteins.
This is (partially) correct. It’s not a question of dough liquor dilution but of solvent quality, i.e., its physicochemical characteristics, such as ionic strength, pH, dielectric constant, etc. (Solutions are seen as being homogeneous, so speaking of “dilution” makes little sense from this perspective.) Solvent quality significantly affects how a solvent interacts with biopolymers.
I read this a while ago, and just re-read it, including the comments and responses. I appreciate how you frame and bring in perspective, Ian. Besides the elasticity and oxidation comments, I have also heard about autolyse kickstarting enzyme activity, resulting in starch breakdown and release of more sugars into the dough before fermentation starts... benefits helping with fermentation and more residual sugars/better crust color. (1) I'd love to hear your thoughts on this. If I am not wrong, I recall you mentioning that such an effect is time-dependent. (2) Can an autolyse step help with more effective hydration of coarser flours, i.e., semolina, if such flour constitute a large portion, like 50%, of the total flour in a recipe? i.e., giving more time for such flour to absorb the liquids prior to starting the mixing and fermentation? Thanks again for all your contributions to the craft!
Another excellent writeup, thank you for your work. Let me try and summarize to see if I'm reading this right: the largest glutenens, which contribute to the dough's elasticity require mechanical agitation (mixing/shear forces) in order to unravel and become fully hydrated. By eliminating full mixing/shear forces at the onset, the other particles (starches pentosans and smaller proteins) preferentially become hydrated, and the largest glutenens are never fully hydrated nor fully unraveled. Since these large glutenens are the main contributors to the dough's elasticity, the doughs peak elasticity is diminished. It's a water thing
I've always struggled with justifying autolyse from the temperature perspective as well. Hard to bring a dough back to temp hours later once all/most of the water has been used up...
Everything in biological systems and material is a "water thing." Its importance cannot be overstated.
For the discussion above, it's better to say it's a "solvent thing." The physicochemical properties of solvents are changeable depending upon their solutes. What's acts as a "good" solvent for one material might be a "poor" solvent for another. Practically speaking, bakers, baristas and brewers experience this when their water is either too soft or too hard.
Phase separation occurs as (i) the aqueous medium (water) becomes poor (as soluble flour components dissolve into the water) for gluten proteins and after (ii) sufficient aggregation of each biopolymer type with itself occurs. It is at that point gluten becomes the continuous phase of a wheat-dough system.
The largest of the proteins cannot participate in network formation ("elasticity") if they're not hydrated (swollen, softened and expanded) and then broken apart into tinier droplets during shear flow. Hydration of their hydrophilic interior requires a "good" solvent.
Thank you, this is very helpful. And if I understand correctly, it bears out what I see in practice. Following advice to employ a two or three-hour autolyse, the stretchy, "developed" dough breaks down quickly upon further mixing and addition of other ingredients.
A helpful way to think about what autolysis does is to imagine a normally-mixed control dough and an autolysed dough. The control will always be the stronger of the two, so we can set its peak elasticity value as a baseline of 100. The only difference we will see in an autolysed dough is a decrease of that baseline, which may see its peak elasticity values drop to 70 to 75 relative to the baseline.
A corollary to the above is the observation, by Calvel and advocates of autolysis, that an autolysis step decreases total mixing time (if measuring only when the mixer's turned on). This is technically true. The amount of mixing required to arrive at peak development (quantified by rate and total mechanical energy input) is determined, in a linear fashion, by the total quantity of what researchers refer to "glutenin macropolymer (GMP)," alternatively known as "unextractable polymeric protein (UPP)."
The total quantity of GMP possible is lowered in doughs that have undergone an autolysis step. Hence, they require lower total mixing times.
I went back to re-read Calvel and there was the claim that autolysis ..."reduces the total mixing time (and therefore the dough's oxidation) by approximately 15%, facilitates the molding of unbaked loaves, and produces bread with more volume, better cell structure, and more supple crumb."...
I am very glad to learn that most of this is incorrect, because over the years since I first encountered the idea (2009), people seem to have become progressively more attached to the idea. Long autolysis times show up in most recipes I try, and it will be a joy to abandon the practice!! I understand the desire to reduce mixing time in, say, panettone, to avoid overheating the dough. However, in practice I haven't seen the benefit, as it is rarely a pick-it-up-from-there process in terms of dough development.
Perhaps dive-arm mixers are the best of both worlds, since they work on the dough slowly, giving it more time to accept water as you go.
And yes, James MacGuire is a great guy, honest and humble as we all should be.
Autolysis does not reduce oxidation, nor is oxidation necessarily a negative phenomenon. (Fermentation, for instance, is itself an oxidative process.) As an issue, its importance has been both misunderstood and blown out of proportion by today's bakers, all because, it seems, none have read Calvel's original works and suggested mixing times.
My best piece of advice is, ignore oxidation, or, better, do not let it be a worry.
This was a very interesting read. Thanks for taking the time to explain this so carefully. I know the above is a discussion about autolysis and many of my questions have already been answered in the comments here. But, I've got three questions that at least partially relate to this that I'd be grateful if you took the time to answer.
Q1: Why does bassinage work? In my experience it makes a dough of a said hydration more elastic than a dough at the same hydration that wasn't mixed using bassinage, assuming total mixing time is the same. As I understand from above the shear flow from the mechanical mixing helps to unfold the large hydrophilic glutenin molecules so as to increase their surface area and ad/absorb more water. At a certain point in the mix, after a long slow mix and a few minutes on 2nd, the dough looks very elastic to me, balls up around the hook, and I add the remaining water. What, on the macromolecular level, happens as this extra water is added in 2nd speed?
Q2: What does it mean on the same scale level, that a dough is over-developed, rips, loses its elasticity, becomes wet and sticky? Does this have to do with water distribution between the gluten, starch, pentosans and the aqueous phase?
Q3: As we include salt from the start of the mix, rather than delaying its addition until the very end (which I've done for years), doesn't it mean it "uses" a part of the water in the aqueous phase from the start and thus leave less water for the gluten parts to ad/absorb? I've noticed doughs develop faster from the onset if salt goes in at the start, but that they also more easily get over-mixed - tear apart. Please elaborate if you have the time.
Greetings from a sourdough baker.
Any thoughts on this?
This is great, Ian. I've done an autolyse on my doughs for years, since I was trained in part by my friend James MacGuire, who was a friend of Calvel's (and his English translator). But I've recently ditched it and haven't really noticed any negative consequences and think you are correct.
A few questions:
- Do you see any benefit to a "hydration" rest before mixing when working with high-extraction or whole grain flours, as a means to let the bran hydrate? I have found that even a short rest can result in a less shaggy dough and what seems like more efficient mixing. I suppose this might work similarly with or without the salt and/or preferments, so it could still be done in the absence of a strict autolyse.
- I've found that holding back the salt is helpful for mixing efficiency when hand mixing—it helps to let the flour hydrate evenly and avoid clumping. Even if I am not doing an autolyse, I'll often hold back the salt until I've mixed the flour and water, then immediately add it. Do you see any downsides to doing this, in terms of ultimate dough strength?
- Is saying that an autolyse compromises dough elasticity the same as saying that it *increases* extensibility? If so, that might be a reason to do it, if increasing extensibility were the goal. (This was a common refrain on pizza making forums for years, that adding a brief autolyse made dough balls more easy to stretch.)
Also: glad you are back posting here, will mention it to my readers soon.
Remember my framework for evaluating whether or not you should do something. Does it bring you joy? Does it help you achieve your desired end result? If yes to both, do it.
Q1. My above comments pertain to low-extraction flours. Once you throw the baby and the bath water in, all bets are off. That’s another way of saying, the phase-separation and water-distribution characteristics of whole-grain or high-extraction flours differ greatly compared to white flour. If you find a “rest” period, in which the larger constituents (bran and cell-wall polysaccharides) hydrate, helps, go for it. I assume you’re only referring to mixing in smaller quantities and/or hand-mixing. It should result in a softer dough, albeit one with an even greater decrease in elasticity values. Decreases in elasticity value also correspond to decreases in final-product volume.
Q2. My guess is the answer is flour-dependent. New-world flours are strong. Like USSR competing in the ‘80s Olympics strong. The quantity and size of the largest glutenins in such flours means they require more energy input, both in terms of rate and total amount, relative to softer and/or weaker flours in order to ensure those large glutenins are able to participate in gel-network formation. The fact is, most amateur (and many professional) bakers using stronger, new-world flours do not mix enough to achieve a sufficiently soft dough. They therefore seek other alternatives to “soften,” e.g., increasing hydration, using an extended autolysis, and so on. Salt decreases the quantity of water in the gluten phase and increases gluten protein self-association. I do not believe there are any trade-offs to holding back salt when making bread in small quantities. (In professional settings, I advise against it, only as one less thing to forget. This matters in high-throughput settings. Salt can then be pre-weighed the day before and included with other dry components that are added at the beginning of the mixing process. Remember my other rule: I don’t like to think when I bake. This allows me to focus on what matters, minimising variation of process and hence product.)
Q3. No, decreasing elasticity values is not equivalent to saying it increases extensibility. Extensibility is its own rheological measure, quantified by two scalar values. The total distance a dough can be stretched before rupture, and the energy input at the point of rupture. People focus on the second of these two quantities. “How easy it is to stretch” is not the same as “how far it stretches.” It’s an error to focus on the wrong parameter with considerable downstream consequences on product quality.
In wheat dough products where an elongational process is required, like pizza or baguette, if your product is fighting you, the answer is, almost without exception, never autolyse. Why? Because product volume will suffer. Diminished volume in products requiring elongation impacts final quality much more relative to those products with lower or minimal elongational requirements. Wheat flour products requiring high elongation values are part of a larger class of products that have high ratios of surface area to interior volume (SA:V). High SA:V products include ciabatta, flat breads, bread sticks, baguettes, crackers, cookies, biscuits, many styles of cake or quick breads (scones or drop biscuits), and so on.
This class of products all display horizontality (in the X- and Z-axes), called “spread” in cookies. You’ll notice another commonality: The biggest “faults” perceived by consumers in such products are textural, such as “toughness” or “shortness,’’ which results from incorrect choices made in process, raw material, or formulation. The most important parameter to combat product toughness in this class of products is to maximise final volume, followed by ensuring all variables (raw material, formulation, and processing) conform to this goal.
An autolysis step does not fall into the solution types that maximise product volume. (Remember, in biologically-leavened wheat-flour products, the maximum volume achievable is directly determined by maximum elasticity values that are attainable. The latter parameter, in turn, is directly determined by the total surface area of “gluten” proteins, particularly the largest-sized glutenins.) Further, an autolysis step will have other trade-offs in such products, such as “shortness.”
The best solution in such products is almost always in choosing the right flour. (“More than 90% of making a great baguette involves simply choosing the correct flour.”) This is why so many new-world pizzamakers import Italian flours like Caputo (though marketing plays a huge role, too). I see this in Australia: Pizza joints choose Caputo without exploring the local option space.
If the correct flour has been chosen, then the baker or pizzamaker should then look at the other parameters that most impact volume. In this case, that variable is (degree of) fermentation followed by formulation.
Lastly, it's great you now James. He's a figure I've always greatly admired but have never met.
Not sure if you are taking requests for future posts here, but I'd love to see you address this topic in more detail:
"The fact is, most amateur (and many professional) bakers using stronger, new-world flours do not mix enough to achieve a sufficiently soft dough."
I've seen you mention this idea many times—that extended mixing increases dough softness—and I'd love to know what "enough" looks like, both in practical terms and in results, especially since most bakers mix to a specific *strength*, and I sense you are talking about something else.
James is a wonderful person, one of my treasured teachers and friends. His health has not been great for the last few years, so he's kept a low profile mostly. His writing—especially his essays for the Art of Eating—are ones I recommend to everyone.
Hi Ian, thanks for the in-depth knowledge sharing. This is the longest answer I ever get from asking a question. I have to say it’s all very technical, I managed to grasp some ideas but I cannot say I fully understand. I probably need to go over it a few more times.
I have a question regarding your advice to make a no-knead bread instead. It greatly confuses me. If hydrating flours (autolysis) alone doesn’t help develop gluten, how does a no-knead bread develop its gluten? There is no kneading/folding whatsoever.
Let me be more specific with my question. You mentioned in one of the comments above “You need to plasticise, liquidise and break up the largest glutenin particles so they can ad/absorb water before solvent quality is altered.”, so when making a no-knead bread, which stage in the process is the large glutenin particles get break up and allowed to absorb water, don’t you just combine the ingredients and leave to bulk in a no-knead bread? If glutenins cannot fully absorb all the water they need before solvent quality degrades, then how is a no-knead bread different from performing an autolysis? Please shed some lights when you have the time. Thank you so much!
I never claimed the no-knead bread process results in a fully-developed dough, and that’s the point. If, as a baker, you’re willing to use an autolysis step, and do more work for “less” results (diminished volume, decreased dough development), why not just make no-knead bread? It’ll give you comparable results for less work.
Hi Ian, I want to thank you first of all for all the knowledge you shared on Instagram in these years. I cannot remember an instagram story of yours I did not take notes about.
For what I understood, shear during mixing is thus basically responsible for protein unfolding, especially the biggest ones, and unfolded proteins wet more easily since they have more "wetted microstates" than folded ones. Is this mechanism is somewhat independent of the "solvent quality", since you wrote that polysaccharides wetting happens earlier than protein wetting, or the very purpose of mixing is to "anticipate" protein wetting so that they can compete with polysaccharides for water? I would go for the second since I'm assuming that the amount of water molecules in the dough is order of magnitudes more than the average number of bindings at every time, otherwise there would be no water left for yeasts and bacterias. Proteins would always have enough water to saturate all their bindings even in the unfolded state, but without shear flow no fluctuations in reasonable time would break the folded state to let them bind with water.
Should I deduce anyway then that wetting speedup due to shear flow does not apply to polysaccharides since those chains do not have only one microstate?
Also, while I remember the picture of the dispersed polysaccharides phases in the continuous "gluten" phase from your GrAiNz presentation, I don't understand what you mean when you refer to the gel (I must say my knowledge of soft matter is lacking)
Lastly, I would naively say that no-knead is autolysis without mixing next, so I don't understand within this picture you made how dough could develop any structure with no-knead.
I appreciate if you will ever find time to answer my questions, and look forward to the next post!
Michele
I believe you’re focusing on the wrong scale of causal determination. Your question presumes we should look at the problem through a water molecule’s eyes. Most food science makes the same error.
If we did adopt the view at the level of electrostatic interactions, then we’d end up with a major paradox: How is it that water doesn’t spill out from a dough all over the floor? After all, there’s barely enough hydrophilic sites in flour biopolymers to cover all of them in a monolayer of water one water molecule thick.
You cannot resolve this puzzle at the level of the hydrogen bond. It’d be like trying to explain why I’m bad at Pac-Man by looking at the CPU’s machine code. There’s simply no determinative causality at that scale.
Don’t think of the problem using microstates. That’s where food scientists designing experiments probing water’s behaviour in food systems get in trouble. They’re probing the wrong space-time scale length. It’s better to think of water as a bulk material described using statistical mechanics.
In condensed, porous material, water’s held in place by pressure differentials, not hydrogen bonds. Free hydrophilic sites may contribute to that overall force differential, but, as you state, it’s far from the whole story. It’s the same mechanism behind why sponges absorb water, or why liquids climb up the inside straws.
I’m not sure where you’re getting the idea that polysaccharide wetting occurs before (or faster than?) protein. I didn’t mention polysaccharides in my post. They certainly play a huge role in this discussion, particularly soluble and insoluble arabinoxylans, due to their much larger size and greater hydrophilicity.
If the pentosans are allowed to hydrate fully before the largest molecular weight glutenins, this shifts the phase-separation threshold with greater gluten network discontinuity due to excluded volume effects and thermodynamic incompatibility.
Shear flow has a substantial impact on all polysaccharide hydration, particularly for pentosans. However, not in the same way as gluten proteins, which are thixotropic. This means that, below their glass-transition temperature and in the presence of sufficient plasticiser (as in dough conditions), they reversibly fluidise. Pentosans don’t do this, as when they participate in irreversible gels. (“Gluten” is a reversible, physical gel stabilised directly and indirectly by non-covalent interactions. Add shear and plasticiser, and the gel becomes fluid. Remove the shear, it becomes solid.)
What determines strength in wheat doughs is the average molecular weight and total concentration of the largest-sized glutenins (or “glutenin macropolymer,” or GMP). A “weak” flour may only contain 0.7% GMP of small size. The average European flour will have 2% of medium molecular size. A very strong flour may contain up to 3.5% of very large size.
In their native state, polysaccharides are 1 to 3 orders of magnitude larger than even the biggest glutenins. This means they have much greater internal surface area to suck water into, and, in the case of pentosans, much greater hydrophilicity.
So, yes, solvent quality does matter. What’s a poor solvent for “gluten” may be a great solvent for pentosans.
You need to plasticise, liquidise and break up the largest glutenin particles so they can ad/absorb water before solvent quality is altered. Because, once the nature of the solvent changes, any “gluten” proteins that are plasticised, hydrated and swollen will participate in gel-network formation, becoming directly or indirectly stabilised by the non-specific interaction "structure" established by the mixing parameters.
Thank you for your reply. I flew over the problem of water spill-out assuming that water diffusion is much slower then the average hydrogen bond lifetime, so that water "get caught back" by a new bond before it manages to spill out. But I'm not familiar enough with the physical quantities at play to tell if this makes sense or not.
But I still have some trouble understanding how the change in solvent work. First, of all, is what we call here solvent what you called dough liquor during your grainz talk? I would say yes since pentosans and starches repel with glutenins and gliadins.
Say we divide the solid content of flour in insoluble pentosans, starch, gluten, and all the rest that goes into dough liquor (as per the centrifugation studies you mentioned at grainz). Do the four groups take the same amount of time to hydrate? I would say no, as you remarked above about fully hydrated pentosans that shift phase separation threshold. But are you talking about soluble pentosans in dough liquor or to insoluble pentosans in the pentosans gel?
My best mental model so far is that gluten phase takes much more time to hydrate than dough liquor to reach equilibrium if I do autolysis. If straight mixing instead, hydrophilic sites in the forming gluten phase are exposed before complete mixing of soluble flour components in water; this means that the "local dough liquor" seen by gluten proteins in its vicinity is more diluted and so more favorable to wet the proteins.
>>Thank you for your reply. I flew over the problem of water spill-out assuming that water diffusion is much slower then the average hydrogen bond lifetime, so that water "get caught back" by a new bond before it manages to spill out. But I'm not familiar enough with the physical quantities at play to tell if this makes sense or not.
Conceptualising the problem at the hydrogen-bond level has little explanatory power. It’s better to model water as a bulk material that exhibits aggregative statistical properties. We can then chunk water into groups. Each ensemble, at the “group” level, is distinct, and associated with different phases, even if, at the level of individual water molecules, any one particular water molecule is promiscuous. I.e., any one water molecule can be anywhere within the system, constrained only by diffusion kinetics.
>>But I still have some trouble understanding how the change in solvent work. First, of all, is what we call here solvent what you called dough liquor during your grainz talk? I would say yes since pentosans and starches repel with glutenins and gliadins.
Yes, the “solvent” is the dilute, remaining aqueous medium dispersed throughout the entire dough system, not the groups of water associated with each phase.
>>Say we divide the solid content of flour in insoluble pentosans, starch, gluten, and all the rest that goes into dough liquor (as per the centrifugation studies you mentioned at grainz). Do the four groups take the same amount of time to hydrate? I would say no, as you remarked above about fully hydrated pentosans that shift phase separation threshold.
No, they do not hydrate at the same rate, BUT continuous shear flow smooths the distribution kinetics, for several reasons. (One of the reasons is that, depending upon shear-flow velocity, the interaction of water molecules with biopolymers can occur at rates faster than would occur during normal passive diffusion. Liquidising and/or increasing biopolymer surface area aids in the smoothing of this distribution.)
>>But are you talking about soluble pentosans in dough liquor or to insoluble pentosans in the pentosans gel?
For the changes in distribution kinetics between higher-extraction flours and refined flours, I was referring to insoluble pentosans, as the pentosan gel phase increases in size.
For changes in solvent quality, I mean soluble pentosans.
>>My best mental model so far is that gluten phase takes much more time to hydrate than dough liquor to reach equilibrium if I do autolysis.
Correct. The soluble dough constituents would diffuse into the dough liquor at a rate greater than all gluten proteins can hydrate. One thing to remember is that the largest-molecular-weight glutenins will NOT fully hydrate if using a non-continuous mixing process, since they remain as large hydrophobic spherical particles. Their full hydration requires depolymerising them (which requires shear flow of a certain velocity and duration), increasing their surface area.
>>If straight mixing instead, hydrophilic sites in the forming gluten phase are exposed before complete mixing of soluble flour components in water; this means that the "local dough liquor" seen by gluten proteins in its vicinity is more diluted and so more favorable to wet the proteins.
This is (partially) correct. It’s not a question of dough liquor dilution but of solvent quality, i.e., its physicochemical characteristics, such as ionic strength, pH, dielectric constant, etc. (Solutions are seen as being homogeneous, so speaking of “dilution” makes little sense from this perspective.) Solvent quality significantly affects how a solvent interacts with biopolymers.
I read this a while ago, and just re-read it, including the comments and responses. I appreciate how you frame and bring in perspective, Ian. Besides the elasticity and oxidation comments, I have also heard about autolyse kickstarting enzyme activity, resulting in starch breakdown and release of more sugars into the dough before fermentation starts... benefits helping with fermentation and more residual sugars/better crust color. (1) I'd love to hear your thoughts on this. If I am not wrong, I recall you mentioning that such an effect is time-dependent. (2) Can an autolyse step help with more effective hydration of coarser flours, i.e., semolina, if such flour constitute a large portion, like 50%, of the total flour in a recipe? i.e., giving more time for such flour to absorb the liquids prior to starting the mixing and fermentation? Thanks again for all your contributions to the craft!
Another excellent writeup, thank you for your work. Let me try and summarize to see if I'm reading this right: the largest glutenens, which contribute to the dough's elasticity require mechanical agitation (mixing/shear forces) in order to unravel and become fully hydrated. By eliminating full mixing/shear forces at the onset, the other particles (starches pentosans and smaller proteins) preferentially become hydrated, and the largest glutenens are never fully hydrated nor fully unraveled. Since these large glutenens are the main contributors to the dough's elasticity, the doughs peak elasticity is diminished. It's a water thing
I've always struggled with justifying autolyse from the temperature perspective as well. Hard to bring a dough back to temp hours later once all/most of the water has been used up...
Everything in biological systems and material is a "water thing." Its importance cannot be overstated.
For the discussion above, it's better to say it's a "solvent thing." The physicochemical properties of solvents are changeable depending upon their solutes. What's acts as a "good" solvent for one material might be a "poor" solvent for another. Practically speaking, bakers, baristas and brewers experience this when their water is either too soft or too hard.
Phase separation occurs as (i) the aqueous medium (water) becomes poor (as soluble flour components dissolve into the water) for gluten proteins and after (ii) sufficient aggregation of each biopolymer type with itself occurs. It is at that point gluten becomes the continuous phase of a wheat-dough system.
The largest of the proteins cannot participate in network formation ("elasticity") if they're not hydrated (swollen, softened and expanded) and then broken apart into tinier droplets during shear flow. Hydration of their hydrophilic interior requires a "good" solvent.
Thank you, this is very helpful. And if I understand correctly, it bears out what I see in practice. Following advice to employ a two or three-hour autolyse, the stretchy, "developed" dough breaks down quickly upon further mixing and addition of other ingredients.
A helpful way to think about what autolysis does is to imagine a normally-mixed control dough and an autolysed dough. The control will always be the stronger of the two, so we can set its peak elasticity value as a baseline of 100. The only difference we will see in an autolysed dough is a decrease of that baseline, which may see its peak elasticity values drop to 70 to 75 relative to the baseline.
A corollary to the above is the observation, by Calvel and advocates of autolysis, that an autolysis step decreases total mixing time (if measuring only when the mixer's turned on). This is technically true. The amount of mixing required to arrive at peak development (quantified by rate and total mechanical energy input) is determined, in a linear fashion, by the total quantity of what researchers refer to "glutenin macropolymer (GMP)," alternatively known as "unextractable polymeric protein (UPP)."
The total quantity of GMP possible is lowered in doughs that have undergone an autolysis step. Hence, they require lower total mixing times.
I went back to re-read Calvel and there was the claim that autolysis ..."reduces the total mixing time (and therefore the dough's oxidation) by approximately 15%, facilitates the molding of unbaked loaves, and produces bread with more volume, better cell structure, and more supple crumb."...
I am very glad to learn that most of this is incorrect, because over the years since I first encountered the idea (2009), people seem to have become progressively more attached to the idea. Long autolysis times show up in most recipes I try, and it will be a joy to abandon the practice!! I understand the desire to reduce mixing time in, say, panettone, to avoid overheating the dough. However, in practice I haven't seen the benefit, as it is rarely a pick-it-up-from-there process in terms of dough development.
Perhaps dive-arm mixers are the best of both worlds, since they work on the dough slowly, giving it more time to accept water as you go.
And yes, James MacGuire is a great guy, honest and humble as we all should be.
Hi Ian, thanks for sharing all these priceless information and sorry if I’m going to be inaccurate but I’m doing my best and still learning.
Right now I’m a Calvel’s autolysis fan intended in the way of reducing mixing time and thus dough oxidation.
If I undetstood correctly by saying “if measuring only when the mixer’s turned on” you’re considering autolysing as “mixing time”, right?
How oxidation is involved in this part of the process?
Just to explain I intend oxidation as an negative effect on flour’s original flavours.
Autolysis does not reduce oxidation, nor is oxidation necessarily a negative phenomenon. (Fermentation, for instance, is itself an oxidative process.) As an issue, its importance has been both misunderstood and blown out of proportion by today's bakers, all because, it seems, none have read Calvel's original works and suggested mixing times.
My best piece of advice is, ignore oxidation, or, better, do not let it be a worry.