Fermentation/Proofing

Fermentation, in this instance, is the process whereby yeast break down sugars into carbon dioxide and ethanol. The alcohol produced during fermentation evaporates during the baking process. Proofing is the term used for the process of allowing bread dough to rise due to fermentation by yeast. They both sound simple enough – and they are, provided the yeast are kept alive (yeast).

One of the main questions commonly asked regarding proofing is “How long do I proof my dough?” There is no simple answer. In reality proofing time will depend on a number of factors, such as:  

  • Temperature - What is the proofing temperature (See yeast).
  • Ingredients - Have other ingredients been added to the dough? These may adversely affect the yeast.
  • Taste – Yeast contribute to the taste of the bread. The initial 2 tsp of yeast (dried) used with Bakers' Magic Gluten free flour does not impart too strong a flavour. However, the flavour may change depending on how long you proof the dough. When yeast are left to ferment for a long time they will have usually used up any available sugars and will start using the starches present as a food source. As a result there may be subtle changes in the texture and taste of the final product.
  • Texture - What texture do you want your bread to have? Do you want a large coarse crumb or a tighter crumb?
  • Time – How much time do you have? As yeast can grow at different temperatures it means that we can tailor the length of time that is required for proofing.
  • Yeast - It will depend on the type of yeast or starter that is used. The following are some examples that can be used instead of dried yeast; fresh yeast, Preferment sponge, Preferment pre-dough, Preferment sours and starters. Preferments contain a portion of Bakers' Magic Gluten free flour, the yeast, sugar & some liquid; they are left to ferment for a length of time (~ 30 min to 3 days). One reason they are used is to allow the yeast to start fermenting without interference from other ingredients, another is for the development of flavour. A preferment sponge differs to that of a preferment pre-dough in the amount of liquid that is added to it. The sours differ in that they have been fermenting for a couple of days prior to use in bread making (eg. sourdough loaves). Technically preferment sours and starters are made with “wild” yeast.

When making bread dried (or fresh) yeast can be added in either one or two steps. The easiest method is adding the dried yeast in with the rest of the ingredients and mixing. The second is activating the yeast first and then adding the activated yeast to Bakers' Magic Gluten free flour. Activating the yeast can be achieved by the use of preferments (mentioned above) or by adding the yeast to warm water containing some sugar. I prefer to start the yeast in water with sugar as you can find out pretty quickly (~ 5 min) that the yeast is okay, additionally it allows for a good dispersion of active yeast in the dough during mixing. 

Usually a wheat flour bread recipe will include a second proofing (mix, knead, rise, punch down, shape, rise & bake). The second proofing can provide; a longer time for gluten development, a better texture (crumb) in the baked loaf and a stronger flavour. In wheat based dough the gluten traps the carbon dioxide when the dough rises; hence the need for good gluten development. As there is no gluten in Bakers' Magic Gluten free flour there is no need for a second rise. However, a combination of the starches, protein and dietary fibre in the Real Bread mix also traps carbon dioxide; it is present at the end of mixing. It is therefore important that the initial mixing is as thorough as possible. Once mixing is finished the dough can be put straight into the baking tin and allowed to proof in there. 

Comparison of Proofing Times

As stated previously the proofing time when making bread with Bakers' Magic Gluten free flour will depend on a number of factors. However, if the majority of the factors remain the same and the only factor that is changed is time we should get a good indication of the effect time has on proofing. Below are photos of loaves (hydration 120%) that were proofed at ~ 270 C for 0, 15, 40 and 70 minutes (starting with the slice on the left). The bread resulting from having “zero” proofing time has risen a little. The yeast was activated prior to mixing; some rise in the dough will occur in the oven during the initial stages of baking (oven spring).

allproof400011

Basically the longer the proofing time the coarser the crumb and the more intense the flavour. Flexibility is also increased with increasing proofing time, while the holes associated with steam leavening decrease (See holes and glug).

 

So which one to choose? Ultimately it is up to you and your family. I think the bread that was proofed for 40 minutes looks the best out of the loaves shown. It also tasted the best according to my children. They came home from school hungry looking for something to eat. They tried a piece from each of the loaves and then completely ate the remainder of the 40 minute proofed loaf – and wanted more of it!

proof0200011

Proofing for 0 min

proof15100011

           Proofing for 15 min

proof4000011

Proofing for 40 min

proof70100011

Proofing for 70 min

Overproofing – When the dough collapses during baking, the dough has risen as far as it can go. Essentially it cannot support the structure, it has been stretched to its breaking point. Proofing for 70 mins = overproofed for the conditions used above.

Ovenspring – This is the term given to the extra rise from the dough during the initial stages of baking. Some of this is due to steam leavening (See holes and glug) and some due to fermentation by the yeast before it expires.

Steam leavening – Steam leavening occurs during the baking process when the water present in dough expands as it turns into steam.