June 10, 2009 - 1:56pm
Why use a preferment?
Why make bread using a preferment? Why not just ferment the total amount of ingredients for the same time as it takes to make the prefermented dough plus the addition of the remaining flour and yeast in the recipe? Would this not make the bead taste better as the total amount of flour will have been fermented for longer?
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If you ferment the whole thing, it can actually over proof the dough so it doesn't have maximum lift for the second rise and the baking. Try the famous no knead bread (I've recently been playing with the Sicilian bread recipe here http://www.breadtopia.com/sicilian-no-knead-bread/) and you'll find that the results are a good bread, but the crumb is usually glutenous and shiny rather than the soft, fluffy texture that you get using a preferment with other flour. A preferment gives you what I call "that flavor" good bread has, plus the softer texture we associate with most bread.
Try both side by side, experimentation is the best way to learn.
-Verminius Rex
Well, actually, many recipes do just that. Heck, overnight retarding of a sourdough loaf is basically just that. As are the cold, overnight fermentation techniques championed these days.
But the key is slow fermentation. As the other poster points out, if you were to do a long, room-temperature fermentation, you'd a) exhaust the sugars in the flour, starving the yeast, and b) cause gluten breakdown (the combination of these two is the definition of over-proofing).
But if you don't have room in your fridge, or if you want to make a lot of bread (say a bunch of loaves of french bread), then a preferment is more convenient, as it give you the additional flavour without having to cold ferment a large volume of dough.
I do it all the time. In fact, it's a lot simpler.
No, you do not exhaust the sugars in the flour - unless you let the whole thing sit at room temperature for more than 24 hours.
I mix all my ingredients with a spoon and let it sit overnight (or longer - up to 24 hours). Then, I stretch and fold the dough a few times to develop the gluten. An hour later, I final shape and then bake. Works like a charm.
Alternatively, you can mix S&F and put the dough in the fridge for an overnight (or several day) retard. You get a slightly different result, but it's excellent all the same.
Interesting! I'm guessing the key, here, is you do a nice, long bulk ferment, and *then* develop the gluten. This prevents the yeast and bacterial activity from breaking down the gluten structure.
Might have to try this some time... :)
But isn't the gluten developing by itself just sitting there, especially with a wetter dough?
To the OP, from what I've been reading I think one reason is that for a long, slow pre-ferment you want a small amount of yeast (so as not to exhaust the sugars), but for the final dough you might need more yeast, so splitting the batch allows you to reconcile this. Also some flours are said to have poorer gluten quality (e.g. rye) than others, and can't be fermented as long, so you might ferment the wheat flour portion first, then add the rye later. At least that's the theory I've been reading. I hope others will correct me if this is wrong.
"But isn't the gluten developing by itself just sitting there, especially with a wetter dough?"
Certainly true. But then the subsequent stretching and foldering further builds the gluten network, compensating for any breakdown caused by the long fermentation.
At least, that's my guess... but, quite honestly, what the heck do I know? :)
My pizza dough and the Anis Boubasa recipe for baguette are both fermented as a whole for 24 hours. It's seems to be a matter of how much yeast to use, and I wouldn't know how to convert my "preferment" recipes..if I did, I would make all my breads like this....it's the least amount of trouble for me.
There must be other issues also that would be interesting because my pizza dough recipe and Anis Boubasa baguette recipe are the same, but for some reason, the pizza dough works better with a teaspoon of instant yeast, and the original baguette recipe works with 1/4 teaspoon of yeast....
I remember from my beer brewing days that the yeast population will grow rapidly until it peaks. After which time, the fermentation activity is the same. So the difference between two doughs, one made with a very small amount of yeast and another made with more would be the area under the yeast-over-time curve. In other words, the period of time that the dough is experiencing yeast reproduction and a slower fermentation rate.
At room temperature, this is not such a big deal - maybe three hours (pulling a number out from memory - I'd have to check my Charlie Papazian books...)
This is slowed by retardation and subsequently, the benefits of slow multiplication is exaggerated. I guess that your yeast population is not peaked after 24 hours in the fridge. Otherwise, you wouldn't see a difference between your doughs.
Do you just shape your pizza, top it and bake? If that's the case, your pizza dough probably needs a lot more yeast than your baguette dough because it doesn't get a final proofing period and has less time for the population of yeast to raise the dough.
Anyway, I reckon that if you make Anis-type dough for pizza, but let it sit at room temperature for 24 hours, it would behave as if you used more yeast since they would have more time to multiply.
There is a lot more going on once the flour is wetted, There are lots of complex changes taking place, starches being converted to sugars (enzyme action) and yeast changing sugars into gas and alcohol.
With a ferment you are allowing more time for this to happen.
The ammount of yeast present will determin the speed of fermentation.
commercial yeast has a narrow comfort range and it will perform at its best in the dough around 28 deg centigrade.
retarding slows the yeasts power to reproduce itself and its ability to produce gas and alcohol.
2 identical doughs finished at the same temperature can be made to mature at very different rates just by the ammounts of yeast included in the mix.
regards yozza
Thanks for all this info. The plot thickens..