Random questions which you may be able to answer
1) Autolysation. If the longer you do it, the more strength it builds, why not autolyse overnight or even longer, adding the starter next day? Why do recipes usually call for a half hour or an hour? Is it possible to over-autolyse?
2) Different recipes call for different amounts of levain. What's the rule for the amount of levain used in a recipe? If I use 20% levain, how will the process differ than if I use 10% levain? Does it simply alter bulk fermentation timings or does it alter the character and taste of the bread?
3) the same question with the unactivated starter. How much should I add to my flour and water and why? Again is it just a question of timings ie the more percentage of starter I add the quicker it will double?
4) steam. How much steam is optimum for baking bread? My oven has three settings for adding steam. Low, medium and high. Which one should I use and why?
5) Steam again. Should I use steam for the whole baking time? for the first 25%? Half? Should the loaf be finished in a dry environment?
6) scoring. I make breads between 64% and 68% hydration, proved overnight in the fridge. Whenever I score (at an angle, with a lathe) I find that the loaf spreads out rather than keeps its shape. I tend to end up with nice loaves but the score doesn't develop ears, rather it just spreads outwards and upwards and the score creates a nice pattern but it's flat to the crust. Is this because my dough hasn't developed enough structure? Is it because it's just a little too highly hydrated? Do I simply need to make a dough with less hydration so the dough doesn't spread when I slash?
7) stretching. I stretch my dough in the mixing bowl it ferments in. I tend to do this by lifting from the back until the whole dough peels off. Often this can be a very lonnnnnng stretch. Is this ok or should I be doing smaller stretches?
8) stretching again. Is it possible to overstretch or can no dough get enough of it to develop strength?
If anyone has any definitive answers to these puzzlements that keep me awake, I would love to hear. thank you.
Ben, first, the easiest question is the last line - no there are no definitive answers to any of your questions. There are just too many variables, and different goals in terms of taste and appearance.
Autolyze - you can go longer, though some report dough degradation if it goes too long.
Levian percentages - varying percentages impact flavor. Some suggest the smaller the amount of flour, the more sour the dough although others suggest that once you get above certain percentages, the high the percent, the more sour the dough. In general, the longer the bulk ferment, up to a point, the more "flavorful" the bread. Sort of like red wine.
Scoring is not a skill I can say I have mastered, but it involves both the dough and the blade. Assuming you are using the blade correctly, if the dough is overproofed, you will not develop ears. Others say that ears come and go. I find that ears are pretty elusive, but are more common when the bread goes into the oven slightly underproofed.
Steam, general rule of them is introduce the maximum amount of steam to keep the outer side of the loaf soft and able to expand, and vent all steam after 1/3 of the baking time. You can keep steam on the whole time, but the crust will not get much darkening.
Stretching, I pull fairly firmly when I do stretch and folds and have never had a problem - if it rips, that would probably not be good.
Thank you for taking the time. Your thoughts are invaluable as is this whole forum.
Short and sweet. Love it! Thanks for taking the time.
The numbering makes it a lot easier! Wish all did that - Thanks!!
Hi Benjamin,
I'll just concentrate on what I feel moderately confident that I know at least a little about: the autolyse.
This step does five things.
First, it allows the flour the water to more evenly distribute through the dough. This is most handy for a home baker as professional bakers (including most larger 'artisan' bakers will mix the dough with a mixer to accomplish this step. You still need to mix it together moderately well but the autolyse stage allows you to shortcut this a little, reducing mixing (and thus reducing oxidation, which can, at a certain point, become detrimental).
Second, it allows the flour to absorb the water. This is related to the distribution of the water during mixing but is still a separate process and is often expressed as 'hydrating the flour'. Specifically, the water will soak into the starch and protein granules. The coarser the flour, the longer this process will take, particularly for the starch. The length of this process is in part determined by the starch damage, which is, basically, how mashed up and broken down the starch granules are from the milling process. The more starch damage, the easier the water is absorbed. Any bran pieces will also need time to hydrate.
Third, as part of the hydration of the proteins, gluten will start to form.
Gluten is frequently discussed as a single 'thing' for convenience (and I will do so in parts, as well) but it is actually the combination ('aggregate') of two separate proteins: gliadin and glutenin. Both are proteins, which means they are comprised of chains of amino acids that form complex three-dimensional shapes, folding in on themselves and curling up. In this state, they're not really of much use.
In short, the gluten 'network' is formed when individual 'bits' of gliadin start linking together the strands of glutenin.
Hydration is a necessary precursor to this in part because it activates the enzymes (in this case, the proteases) that work to snip the coiled up gliadin into smaller units that are then available to link up the glutenin strands. You could almost think of gliadin being a big ball of blu-tack with the enzymes pulling little pieces off that can then be used to stick the glutenin strands together.
So that's a positive. However . . .
The fourth action is that other enzymes also get to work breaking down the newly-formed gluten network.
One (simplistic) way to think of this is like having two groups of people chatting amongst themselves and you want them to form a larger, intermingled group - like a wedding where you have one partner's group separate from the other partner's group.
The protease enzymes (collectively) work to break up the groups so they can then intermingle with each other. The enzymes (again, collectively) keep breaking people up, however, even after they have mingled.
To an extent, this is also a positive as it allows the gluten network to 'morph' and stretch and reform. This is the 'elasticity' we seek.
All sounds good, however the crucial addition is that it is largely the mechanical mixing/kneading/folding as well as the acidification from the yeast/starter that re-develops and strengthens the gluten structure - neither of which are present in the autolyse phase. Beyond the inital gluten-forming headstart from the hydration and beneficial enzyme activity, most of the activity occuring in the autolyse weakens the gluten structure, which does increase extensibility (good), but at the expense of strength (usually less good).
The fifth, and last, action during the autolyse is that other enzymes (the amylases) get to work breaking down the starch into simpler sugars, ready for the yeast to consume. Live the protease enzymes, the amylases are activate and facilitated by the water.
This process will occur during normal fermentation anyway and continue through the entire process of bread making, right up to baking, however, as an autolyse generally occurs without any yeast present, the sugar production is boosted so there is lots of food available in the flour for the yeast, once it is added. (Flour does contain some available sugar as-is so the yeast would have something to feed on anyway but the amylase activity ensures the supply is more plentiful.)
Like the protease enzymes working on the gluten, however, there is no 'off' switch for amylase enzymes and they will digest the available starch until they are unable to continue. Generally, amylase will act on the damaged starch but can - and does - also act on the larger starch granules, though it may take more time.
Enzymatic breakdown of starch is necessary to provide sufficient food for the multiplying yeast, however the more starch that is broken down, the more water is released and the less starch is availale to form a cohesive matrix with the gluten.
Just using some round numbers, starch makes up ~70% of the endosperm so 500gm of pure white flour will contain 350gm of starch. Assuming a starch damage percentage of 6.5%, you will end up with ~23gm of damaged starch that the amylase can easily act on.
Damaged starch will absorb 2-3x its weight in water so, taking the middle ground, that means that that 23gm of fully-hydrated (damaged) starch will release ~57gm of water back into the dough if it is also consumed by the enzymes. This increase in water content in the dough will not go unnoticed.
Again, this is a necessary process but there can be too much of a good thing.
The result
The 'simple' fact is that the gluten building effects of the autolyse are useful but limited, while the gluten degrading effects of enzymes will continue until there is nothing left to degrade - i.e. you end up with batter and not dough.
This puts a limit on how long you can allow this process to continue and still end up with usable dough at the end. This depends on the hydration level and the strength of the flour. The higher the hydration, the quicker this process will progress and the stronger the flour, the more it can withstand the degradation of the enzymes and still remain viable. The fineness of the particle size (e.g. '00' flour being very fine) also impact this as it will hydrate quicker for a given hydration level.
The other thing that impacts this is the enzyme levels inherent in the flour and this varies from cultivar to cultivar, season to season and with growing and harvesting conditions. Flour in Australia, for example is low in these enzymes and I have personally found that I can autolyse for rather a long time without crazy levels of negative effect, despite our flour also being weaker that North American flours.
Some flours also have additional enzymes added to boost the natural levels - US flours are predominantly 'malted', which is to say they contain malted barley and this is added for the purpose of increasing enzyme activity.
Malted barley ('diastic malt) contains protease enzymes that work on the gliadin and glutenin proteins but also amylase enzymes, which work on the starches. Both the enzymes are naturally present in flour but the addition of diastic malt boosts the levels.
Again, Australian flours differ here as our flours do not contain malt, while North American flours do. This is another factor in the abilitiy of a given flour to endure longer autolyse periods (and fermentation) as there are no added enzymes.
Summary
To get back to the question - "If the longer you do it, the more strength it builds, why not autolyse overnight or even longer" - the answer is that the premise is not accurate: the autolyse does not build strength in the gluten network.
What is does do is start the formation of the gluten network due to the action of the protease enzymes making the gliadin more available to bond with the glutenin. That's not a linear increase in strength so much as it is a head-start. While that's happening, however, the proteases are also breaking down the gluten and weaking it.
Using another of my ridiculous and inaccurate analogies, the autolyse helps bring the team together on the field and all stretched-out and limbered-up, ready for training. At which point they can start going through their drills and getting better, without tearing muscles and having other bad sport things happen. If you just leave them there, all assembled but delay starting the training, they're going to start dispersing, wandering about and and you'll find them off playing on their phones or staring at clouds or whatever. Leave it long enough and they'll start getting in their cars and going home or heading to the pub. In other words, they'll relax and spread out and eventually won't be a cohesive team upon which any meaningful training can act.
The result of a suitable autolyse are therefore:
What you end up with, then, is a mass of dough that is 'ready to go' and is both cohesive and extensible, meaning it not only has a gluten network ready to strenghen, that network is 'relaxed' enough to tolerate the mechanical abuse you are about to put it through via kneading and folding and so on. This means you can get right in to nice, big stretches and folders or more vigorous kneading, without the dough tearing.
The longer you leave it after that point, however, the more the gluten network will have degraded, without any additional benefit.
In other words: autolyse long enough to fully hydrate the dough - generally a minimum of 15 minutes (white flour) but usually 30 minutes and perhaps up to 2 hours for whole-wheat/wholemeal flours. In that time, not only will the flour be well hydrated, the enzymes will have had enough time to do all the positive work they are likely to do.
That longer period for whole wheat flours will result in likely undesirable gluten degradation but is at least balanced out by the benefit of more fully hydrated grains.
In short, If you were to leave an adequately hydrated flour-water mixture indefinitely, it would eventually turn to soup.
Final words
All of the above assumes a 'classic' autolyse of just flour and water. Adding salt slows down ALL enzymatic processes (hence its use as a preservative) and also competes for water, slowing and reducing hydration (hence its use for drying).
Enzymes, like yeast, have preferred operating temperatures and reducing the temperature will reduce their activity level (but not the hydration process). Thus, refrigerating the dough at this stage will slow down the 'degradation'.
The combination of that is, if you do want to leave your dough to autolyse overnight due to scheduling then you can refrigerate and/or add some or all of the salt.
On that note, it is possible to have an autolyse WITH the starter. I have seen this referred to as a 'fermentolyse'. This justification here is that a starter - even an active one - will that a little time to get going in your dough and so a short 'autolyse' period (15-20m) will provide most of the benefits before the starter has really managed to begin fermenting the dough to any appreciable degree.
This is a useful and even necessary 'trick' when you have a very liquid starter or levain as these can be difficult to incorporate later and also will generally end up comprising a fair amount of the liquid so autolysing without the starter/levain liquid will result in an inadequately hydrated dough.