The Fresh Loaf

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Does anyone have a temperature system for proofing?

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techieelectric's picture

Does anyone have a temperature system for proofing?

Hello all,

Does anyone have a system of temperature for measuring how long a proof should take? I mean if I'm proofing my normal sourdough as fast as possible I try to maintain the temp. at 26/7 degrees C. and at that temperature the bulk rise and final proof together take about 6 hrs.  I was wondering if anyone has a way of calculating fairly accurately how much slower the dough works when you lower the temperature, it seems fairly general knowledge that lowering the temp. one degree slows the yeast down by 10%, so at 21/22 C the rise takes twice as long. Clearly however this starts to change as you go lower as the dough doesn't completely stop at 4 degrees in the fridge. A night in the fridge for me, let's say 10 hours, is usually equivalent to about 2hrs rising.  Therefore I wondered if anyone has tried to work out exactly how much longer things take at lower temperatures. Just curious, I tend to like to have things all worked out like that, it's probably partly because of I'm not all that confident about telling when my dough is ready for the oven.



davidg618's picture

When the temperature of  a mass of dough is homogenous, i.e., the same temperature throughout, you can make a pretty good estimate of how long it will take to rise, (there are curves published) but when the mass is suddenly thrust into an instantaneous temperature different environment--like the bottom shelf of your refrigerator, it gets complicated. It takes time, probably hours, for the mass of dough to reach, once again, the same temperature throughout. During the time between the two steady states of chill, the temperature internally changes differently primarily depending on its distance from the surface of the dough mass--there are other secondary influences depending on the ingredients: their elemental structure, and hydration--but temperature difference and mass shape  dominate. Spheres of dough will change temperature faster than cylinders, which in turn change faster than boxed shapes, all else being the same.

In other discouraging words, for the home baker, there's likely no good "rules-of-thumb" available. You could probably work out something for your particular set up--refrigerator, proofing container, diough type, etc.--but it would still be an estimate.

I think your time is better spent gaining more confidence in your knowning when your shaped loaves are ready for the oven.  I use a poke test, and keep notes about the time to proof, and oven results. Fortunately, (or unfortunately, depending on your point of focus) you've got to bake more than just a few, or just ocassionally to gain that confidence. How many? How often? Only you can tell.

Happy baking!

David G.

Incidentally, once the dough mass reaches 4°C throughout, yeast growth is essentally zero; the yeast goes dormant.

jeremiahwasabullfrog's picture

as a general rule of thumb, most chemical reactions happen at about half the rate if you drom the temperature by 10 C. I think fermentation reactions fall within this bracket, so you should find roughly the same for your proofing.

techieelectric's picture

That's helpful, gives me plenty to think about anyway. Could you point out the way to one of the curves that you mention David? I'll practise telling whether the doughs ready with my finger anyway. I suppose the rise I see in the fridge is just the result of the yeast activity while the dough is cooling down then, but do you think therefore that after the dough has cooled to fridge temp. that it doesn't really matter whether you then leave it for 10 or 20 hrs? If the yeast is dormant it seems that would be the case. 

davidg618's picture

All white flour doughs, made with commercial yeast' 10 or 20 hours in the refrigerator is alright. Some TFLer's have reported mixing up 5 loaves of white bread dough, storing it in the refrigerator, and baking one a day until the dough is exhausted. In fact, in some cases the bread flavor may benefit from it. For examples, search for the discussions on Anis Bouabsa baguettes, or dmsnyder's San Joquin sourdough. I personally, have never retarded dough more than 24 hours.Moreover, I think most bakers retard dough mostly for the convenience of fitting baking into their busy schedules. Professional bakers use it especially to manage time in their production schedules.

The acids in sourdoughs will eventually break the gluten in the doughs; and some doughs just don't benefit at all from retarding them. I thnk the latter is true for multigrain doughs, but I've not explored them yet. I research the good, the bad, and the ugly of most everything I put in bread dough.

I think the best advice I can give you, is pick one recipe, and do it repeatedly, tweaking only one thing at a time, until you've got your techniques and timeline to your satisfaction. And reasearch the good and bad effects of dough ingredients on the baking process. Jeff Hamelman's Bread, and Peter Reinhart's The Bread Baker's Apprentice, both have lots of good information in them in addition to good bread formulae, tips, and techniques.

Here is a link to a microbiologist's  paper that attempts to matematically model sourdough behavior in reaction to changing environmental parameters, using controlled growth experiments. It a little bit hard going, but I've gleaned some better understanding of sourdough sloogging through it a couple of times. Your nickname implies you're a techie, so you my enjoy it. The first set of curves displays one yeast strain, and two lactobacterium strains growth rate as a function of temperature.

The strains were examined in laboratory cultures, not dough, but it provides some insight into yeast and bacteria behaviour.

A TLF contributer, Debra Wink, has written two or three (maybe four) excellent posting about the science of sourdough that you can read here. I highly recommend them to you. Search "Debra Wink" in the search box on the left side of the TFL page.

David G