Author Topic: Help me with the smell  (Read 1543 times)

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Offline fazzari

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Help me with the smell
« on: October 04, 2007, 10:55:26 PM »
When I make my favorite roll recipe, I make a poolish which sits for 12 to 16 hours at room temperature.  When the poolish is ready to use it has a very characteristic fermentation smell.

On the other hand, I've been playing around with a pizza dough, which I have let ferment at room temperature for up to 36 hours....(of course it has hardly any yeast).....anyway, at the end of 36 hours, the fermentation smell isn't there.  Even after I scale it, and bag it, and refrigerate it for 3 or 4 days, it doesn't have that smell.  Can anyone tell me the science at work here.

Thank you
John


Online Pete-zza

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Re: Help me with the smell
« Reply #1 on: October 05, 2007, 08:29:44 AM »
John,

I believe that it is the rate of biochemical activity that governs the degree of aroma-contributing byproducts of fermentation.

A typical (classical) poolish uses about 20-80% of the formula water and it is elaborated by adding an equal amount, by weight, of flour (plus yeast). So, by definition, it has 100% hydration. All else being equal, a dough composition (preferment or otherwise) with a high hydration will ferment faster than one with a lower hydration, and the rate of byproducts of fermentation will be greater for the dough with the higher hydration. A poolish also typically contains no salt to slow down the fermentation of the poolish or impede the production of byproducts of fermentation. You didnít indicate how much yeast you use in your poolish but typically for a 12-16 hour poolish, you will need about 0.1% fresh yeast (as a percent of the poolish flour), or 0.05% for ADY or 0.033% for IDY. These amounts assume a room temperature of 80-85 degrees F and a water temperature of 60 degrees F. A change in either of these will, of course, alter the rate of fermentation of the poolish and the rate of production of the byproducts of fermentation. But, after 12-16 hours, you should expect a nice aroma from the poolish. That is quite typical.

By contrast, your room-temperature pizza dough will typically have a considerably lower hydration than your poolish, and if it also has a small amount of yeast as you indicated, and presumably some salt, the rate of fermentation will be much slower than with your poolish. The byproducts of fermentation will continue to be formed while the dough is in the refrigerator, but at a reduced rate because the coolness of the refrigerator slows down the process. I have made cold-fermented doughs using small amounts of yeast and low water temperatures and they have lasted over 15 days in the refrigerator (my max was around 23 days). I donít have the best nose but the 15-day old dough did exhibit aromas of fermentation, especially the aroma of alcohol. Itís been a long while since I last made a poolish, so it is hard to say whether the aromas were much different. The 15-day old dough, however, did bake up nicely (see Reply 110 at http://www.pizzamaking.com/forum/index.php/topic,3985.msg42160.html#msg42160), with crust flavors (and texture and color) more characteristic of naturally leavened crusts. The complexity of crust flavors had to have come from the long period of fermentation.

Peter
« Last Edit: October 05, 2007, 08:31:23 AM by Pete-zza »

Offline fazzari

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Re: Help me with the smell
« Reply #2 on: October 06, 2007, 01:06:49 PM »
And thank you again Peter
You know, although I adore the flavor a poolish can give to bread/pizza dough for a fairly quick product, the flavor of the long rise room temperature dough is simply "very clean" and simply outstanding in my book.

John

Online Pete-zza

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Re: Help me with the smell
« Reply #3 on: October 07, 2007, 09:46:59 PM »

You know, although I adore the flavor a poolish can give to bread/pizza dough for a fairly quick product, the flavor of the long rise room temperature dough is simply "very clean" and simply outstanding in my book.


John,

There are sweet spots, temperature-wise, where yeast, enzymes and bacteria perform their best. One of our members, November, discusses some of these factors at http://www.pizzamaking.com/forum/index.php/topic,4517.msg37892.html#msg37892 (Reply 6) and also at http://www.pizzamaking.com/forum/index.php/topic,4099.msg34276.html#msg34276 (Reply 6).

Peter

« Last Edit: October 07, 2007, 10:16:07 PM by Pete-zza »