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Starter and gluten chemistry

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runningknows's picture
runningknows

Starter and gluten chemistry

I'm having an interesting issue with my starter, or perhaps my bread. If I use starter for high hydration breads (70-80%) that are just KA bread flour, water, salt, and my homegrown sourdough, especially if I retard them, I seem to have a gloopy mess sometimes. Usually I can hand-knead my breads for a while (accordion-style) and they eventually settle down, hold their form, and act nice. However, sometimes it seems like the gluten has trouble forming, especially after prolonged retardation (during bulk fermentation) in the fridge, and the bread doesn't want to play nice when I bring it up for baking, even with several turns of gentle folding. I still come out with nice big holes, good gelatination, and a lovely flavor, it's just I essentially have to pour the bread dough and end up with pretty formless loaves. The weirdest thing is that it doesn't happen all the time. Any thoughts?

jeremiahwasabullfrog's picture
jeremiahwasabullfrog

I guess it's possible that you have some strain of bacteria which is more effective than usual at feeding on gluten proteins. There must be such things in the gene pool somewhere. Since your starter is a mixed culture, it might be that certain conditions favour them , while others do not, hence the inconsistent results.

If you wanted to eliminate the possability, I guess you could brew up another starter and compare.

I'd be half inclined to try a different batch of flour too. Can't think what, but there might be something going on in that area.

 

Best of luck

J

dghdctr's picture
dghdctr

http://www.thefreshloaf.com/node/12629/sourdough-trouble-flat-loaves

The starter you're using has to be in tip-top shape, you can't be using too much of it, and the overnight retardation may be allowing the enzymes in your dough to degrade the gluten structure too much before shaping, proofing, and baking.

There's just too many possibilities to give you a short answer here.  Get Jeffrey Hamelman's book, make a starter and maintain it exactly HIS way, make his Vermont Sourdough several times, and then compare your formula to his using baker's percentage.  That will tell you what's not working so well in your present formula.

--Dan DiMuzio

runningknows's picture
runningknows

Really cool thread, Dan. I guess the one thing I hadn't thought about was using too much starter, which could definitely be the case. I was trying to really boost the sourness of the bread, but from that thread it looks like perhaps I should back off. I may also try looking up and using Hamelman's method... I have been using Andrew Whitley's minimalist starter method, seeding with local rye and then using KA flour for feeding. I've kind of been just experimenting with using my own formulations, and while it's fun and I'm learning a lot perhaps it's time to go back to the masters! Thanks!

Ford's picture
Ford

Excessive protease can cause the degradation of protein. There is some of this enzyme in the flour, but, if you are using milk that has NOT been scalded (190°F) then cooled to the fermentation temperature (~80°F) you may have an overload of protease. Using powdered milk is not a solution unless you are using the special bakers powdered milk. This powdered milk has been heated to a high temperature, whereas the regular grocery store powdered milk is processed at a lower temperature. Pasteurization is not a solution either -- temperature is too low.

Ford

suave's picture
suave

That's not what happens.  The effect of milk on dough has nothing to do with proteases.  You really should read though this thread.

Ford's picture
Ford

I am not sure of your point. Are you correcting me for using the term "protease"? or "denature"? Perhaps I should have said that heating the milk to 190°F will "deactivate the glutathione that acts as a protease." As Dan DiMuzio said "The key concept for a bread baker to know is that this protein fragment (glutathione) interferes with the formation of strong gluten bonds, and relaxes the gluten."

Ford

suave's picture
suave

as basic biochemistry.  Protease (as all -ase's) in an enzyme, which means it itself is protein, a very large molecule, consisting of hundreds of aminoacids.  Protease is actually a rather general term which encompasses a very large number of enzymes that traget proteins, but can do it in very different ways.  Glutathione, on the other hand, is a fairly small molecule consisting of only three aminoacids.  Unlike proteases, it does not destroy proteins.  These are two very different things and should not be mixed. 

Ford's picture
Ford

Thank you for the clarification. For the bakers, scald your milk to produce a stronger gluten network and more lofty loaves.

Ford

suave's picture
suave

I really think that this is the best way to put it, although I can not help but wonder if it is really the case, - in my limited experience not scalding milk did not lead to significantly difficult results.

jcking's picture
jcking

Peter Reinhart's "Whole Grain Breads" pg237... In theory, milk that has been scalded and cooled should produce a taller loaf. This is because scalding, or bringing milk to a simmer, definitely denatures any active enzymes that remain in milk, some of the denatured enzymes are proteases, which could weaken the gluten if they were fully active.

Jim

FlourChild's picture
FlourChild

Prof. R. Calvel used a tiny amount of salt in his starter feeds, in order to inhibit enzyme activity and preserve gluten.  I haven't tried it, but might be worth a go with some discarded starter to see how it reacts.