Autolyse is all about hydration and has nothing to do with proteolytic activity

[DocDough]

Autolyse has nothing to do with proteolytic gluten degradation and everything to do with allowing the flour sufficient time to fully absorb water, and you can prove this to yourself with a simple test. Make up two test doughs, one you let autolyse for 15 min at room temperature, the other you let autolyse for 24 hrs at room temperature. If the process depends on a biological processes (i.e., enzymes) the reaction rate will increase with temperature and the effects will increasee with time (generally doubling the rate for every ~10°C increase in temperature and doubling the effect for every doubling of time). The process runs until it depletes one of the reactants (unless there is a rate limiting step). If the process depends on liquid absorbtion the rate will decline exponentially from the initial condition because there is only a finite amount of water to be absorbed. You will note that after 15 minutes there will be little (no) additional impact by lengthening the autolyse time. This is why commerecial bakeries add about 15 minutes of rest time to their cycle if they incorporate an autolyse in their process. And there is no point in undermixing the dough prior to the sutolyse since you really want to encourage water absorbtion and thus should mix thoroughly (generally until the dough pulls itself off the side of the bowl).

I know this suggests major edits to the text but it is also a topic that is still taught incorrectly at baking schools. The whole topic of proteolytic activity in sourdough is covered in an excellent paper:

Gluten Hydrolysis and Depolymerization during Sourdough Fermentation; by authors - CLAUDIA THIELE, SIMONE GRASSL, AND MICHAEL GÄNZLE

It is easily discovered by searching for the title.

The conclusion is that protease activity that degrades gluten macropolymer (GMP) is essentially zero when the dough pH is above 5.0 and is maximized when the dough pH is in the optimal range for the endogenous wheat flour protease(s) (around pH= 3.8 to 4.1). Thus at initial mix time, when the dough pH is nowhere near 5.0, there is no protease activity that can degrade GMP. You can demonstrate this for yourself by replicating the experiment described in the paper - adding acid (or buffer) to a flour/water dough and watching the rheological properties change with pH. And you can heat sterilize the flour and repeat the experiment if you still don't believe it and the results don't change.

[hendricius]

@DocDough thanks a lot for the issue and suggested read - I'll have a look.

I have run the following experiment in the past:

1. Mix flour and water and let that sit. No starter is added.
2. After 12 hours (depending on flour's gluten content) the dough will start to break down and tear. It literally turns into a soup and will no longer have the strong gluten network.
3. The dough's pH is almost unchanged.

What do you think could cause this if it's not the protease?

[DocDough]

Don't know, but I would be happy to rerun the experiment to see if I can figure it out. What type of flour, what hydration, and what temperature? I assume you were using tap water. We can take the chit chat offline if you like. Email me at docdough at gmail dot com.

[hendricius]

@DocDough I'd appreciate that. Can you send me a quick email over at [email protected]? Let's find a couple of tests we can run and then share the results in the book.

[DocDough]

Traveling this week but this should close the loop. Sounds like a plan. DocSent from my iPhoneOn Dec 10, 2024, at 02:32, Hendrik Kleinwaechter ***@***.***> wrote: @DocDough I'd appreciate that. Can you send me a quick email over at ***@***.***? Let's find a couple of tests we can run and then share the results in the book. —Reply to this email directly, view it on GitHub, or unsubscribe.You are receiving this because you were mentioned.Message ID: ***@***.***>