How long to ferment a GF dough, when to shape, when to bake

The variables affecting dough fermentation time

The benefits of dough long fermentations are multiple. An especially important one is complex flavour development. One other relevant benefit is digestibility (the bread will be easier to digest, because enzymes and lacto acid bacteria will join the party and pre-digest the dough, especially when sourdough or pre-ferments are used).

When fermenting bread or pizza doughs we want to go from point A (just-mixed dough) to point B (perfectly risen and proofed dough). When we ferment a bread for a long time, it does not mean that we get past the point B (e.g., with the same recipe, ferment for 10h instead of 2h), but we rather tweak variables at our disposal in order to slow down or accelerate fermentation. But what are these variables?

1. Temperature. Dough temperature and room temperature are extremely important in affecting the fermentation time. The ideal temperature for the yeasts to start reproducing and converting sugar into starches is somewhere between 26C and 28C. If your dough starts at this temperature, it will kick-off efficiently. Anything higher will accelerate fermentation, anything lower will slow it down. Room temperature will be key in maintaining the dough temperature, or make it decrease or increase over time. But how do we control dough temperature?
   If we want to slow down fermentation, it is simple: moving the dough to the refrigerator (this is called “retarding” the dough).
   If we want to accelerate fermentation or make sure it kick-starts before we move the dough in the refrigerator, still simple: just warm the water up before adding it to the dough. Do some experiments, but generally if you have 24C room temp, flour and water at room temp, if you add water at 33C you should get the dough to be around 27C after mixing, if you do not knead. If you knead for a long time or with a stand mixer, you will wind up with a warmer dough. Make sure you never add water at 40C and above, as it might kill the yeast. The formula you can use as guideline is Water Temperature = 3*Dough Target Temperature – Flour Temperature – Room Temperature – Friction Factor. Friction Factor is 0 if no knead, 1 if you knead by hand, 9 if you knead by machine.
2. Inoculation. Or more simply, the amount of yeast or starter added to the dough. The more yeast/starter amount, the quicker the fermentation. The less yeast/starter amount, the slower the fermentation and potentially the more complex the flavour. I generally work on 20% (baker’s percentage) inoculation for sourdough, 0.4% or less for dry active or instant yeast, but some recipes will have different inoculation when we try to achieve different flavour profiles.
3. Water amount. Or more specifically, “unbound” water (to simplify the concept of water activity, which is very important in microbiology). The more “unbound” water there is, the easier it will be for the yeast and other bacteria to move around and do what they do. By “unbound” water, we mean water that is available and not bound by binders like psyllium husk or by flours. So, the wetter the dough, the easier and potentially faster the fermentation.
4. Salt. Salt competes with yeasts and bacteria for water. Indeed, salt affects the amount of “unbound” water (the more the salt, the less “unbound” water available for the yeast). I generally do not play much with salt amounts, as it is healthier to play with other variables (especially if you plan on raising salt levels). Raise it for taste, do not raise it for slowing the yeast. There are more effective ways (see above).

Temperature and inoculation are my favourite ways of affecting flavour development and digestibility of the bread. In particular, with a given amount of yeast, you can make breads with different acidity and flavour profiles by “retarding” in the refrigerator either the first rise of the bread (bulk fermentation) or the second rise of the bread (proofing, which is after the bread is shaped). I use both methods for breads, while I generally retard the bulk fermentation for pizza (I find it more convenient, and it is the traditional way it is done). The general steps for making a good bread are:

• Autolyse (optional) – mixing water and flours 20min+ before adding yeast and salt
• Mixing
• Bulk Fermentation (it starts when you mix the yeast into the dough, it can be “retarded” in the refrigerator)
• Shaping
• Proofing (second rise, in a container of the appropriate shape; it can be “retarded” in the refrigerator, if the bulk was not retarded).

You might ask: hey, if your yeast is different than mine (in the sourdough case), and your kitchen is at a different temperature, how do I know when to shape the bread? How do I know when to bake it?

Read clues given by your gluten-free dough: long refrigerated proofing

For this type of gluten-free dough fermentation, I follow these guidelines:

• I mixed the dough and waited some time. When do I shape it and let it proof? Yeasts take some time to reproduce and consumes oxygen within the dough. However, once the yeasts is done consuming oxygen it will start producing gases that make the dough rise. If you look at the way your starter rises after a feed, you know what I am talking about. It looks likes it is doing nothing for 2h to 2h30min, then it gains momentum and produces gases that makes the dough rise quickly. This is also often called “acceleration”.
  Considering gluten-free flours retain less gases than gluten-containing flours, I refrain from degassing the dough too much. This is even more relevant for sourdough, which produces less rise than baker’s yeast. To avoid de-gassing too much, I tend to shape the dough when it starts to rise, but it is still significantly off the 50% increase mark (this can take hours in some recipes). In this way, I do not worry too much about degassing, I shape the dough right at the time when gas-production is gaining momentum. In this way, I will have a dough that is partially fermented, slightly risen, and changed in texture, but I will minimise the amount of gas lost during shaping. However, if your dough is past this point, do not be afraid of shaping it anyway! Gluten-free doughs do not retain enough gas, but it does not mean that the yeast has stopped producing it. It is possible that a dough that has stopped rising will rise again if degassed a bit. You can see this effect on this time lapse, where I feed my sourdough starter but de-gas it when it reaches its peak. It rises again.
• I have shaped my dough, which is now proofing. When do I know when it is ready to be refrigerated? Once you finish shaping the dough and it is moved within its proofing container, take a good look at it! You will wait some time (usually suggested in the recipe) and then move it to the refrigerator for several hours. You want to make sure the dough is rising a little bit (i.e., it is in the phase where yeast has gained a lot of momentum and producing gas). You can also touch it and see how soft and gassy it is. However, with this method, do not worry too much because the dough will have a very long time to finish proof in the refrigerator. Refrigeration will slow the activity of yeast considerably but will not stop it. If anything, err on the side of refrigerating the dough a bit earlier than a later (to avoid risk of over-fermenting during the very long refrigerated proof).
• When do I bake the bread? Just follow the suggested time in recipes, generally after 12h to 15h refrigeration for sourdough breads. You can bake it straight out of the fridge, no need for it to come at room temperature!

Read clues given by your gluten-free dough: long bulk fermentation

For this type of gluten-free dough fermentation, I follow the following guidelines:

• I mixed the dough. When do I refrigerate it? Yeasted bread? You can move it to the fridge right away after mixing (unless you have some folds to do in the recipe). Sourdough bread? Give the yeast a head start of 30min (when it is warm, say >=27C) to 1h (when it is cold, say <=24C), then refrigerate. If you want to go for a very long one, say 48h, you can skip the head start even in sourdough.
• When do I pull it out of the fridge and shape it? The beauty of this method is that you have a lot of control. You can see the dough slowly rising (or not rising at all) in the refrigerator and you choose, based on your schedule, when to pull it out. Let it stay a minimum of 12h, but then it is your call! Just avoid over fermenting it, but it would likely take days to over-ferment it in most recipes. Still, we want the dough to be at a stage where the yeast has not finished producing gases yet, as we will need to shape it and potentially de-gas it a bit.
• I have shaped my dough, which is now proofing. When do I bake it? Once you finish shaping the dough and it is moved in its proofing container, take a good look at it! You will have some visual clues on the fermentation: the dough will rise, become more gassy and lighter, hopefully more “rounded” or puffed up. An additional check is the poke test: press a finger into the dough, gently. If it springs back rapidly, it is likely under-proofed. If it does not spring back at all, it might be over-proofed. If it springs back steadily but then slows down and leaves a slight indentation, it is good to be baked. However, these are only guidelines. You will learn to understand your doughs, with experience. And never toss a dough away! Regardless of it looking over or under, just bake it!

Now it’s your chance to put all these tips into pratice! Check out my gluten-free bread recipes! I also have a youtube playlist where I show how to do most steps in gluten-free bread making.