November 26, 2017 - 1:15pm
scientific explanation needed
Can anybody offer me a microbial explanation as to why so many books insist on using rye starters for rye breads and white starters for white breads? It seems that this is about more than just flavor.
I'd prefer to have one starter/mother than can make all varieties of bread. However, I read over and over again that if the final bread has a certain percentage of rye, that a rye starter is required. I'm wondering why.
Another open question: do you keep one starter for various breads? If so, do you use a blend of flours?
Share
I'm also assuming there's no harm in keeping one starter and a little while before making the bread start to build a rye starter from it so you end up with a pure rye starter.
Scientifically? I think it's more food science and flavour.
Mother - Levain - Final Mix.
My mother is all white flour. When I make rye bread I include about 10 - 20% of the mother in an all-rye levain. The levain will typically represent about 10 - 20% of the final mix.
In a 900 gram loaf of bread the levain might be as high as 180 grams. If the levain was 180 grams the mother might be as high as 36 grams. If the mother was at a 100% hydration the white flour would total about 18 grams, or around 2% if we stick with the high side of 20%.
It is hard to believe that 2% white flour is going to have any effect on the end product, either for the better or worse. In addition, most formulas for rye bread have some percentage of white flour as an ingredient in the final mix - usually more white than rye. The loaf needs the added gluten the rye cannot provide.
Now with that said, I do believe that a high percentage of white flour in the levain may work against the process. My rye levains are very fast-developing and quite impressive! Rye has a higher enzymatic content so things happen faster. Messing with the rye quantity in the levain too much could affect that development.
So, exactly how does the 2% white flour in the levain screw things up? You got me.
The only thing I can surmise and this is pure conjecture, is that there are a lot of things going on in the living community that are trained through regular maintenance of the mother to select for the rye environment. Thus, I suppose if you want your final dough, which is composed largely of rye to be at its best, you need your seed culture and levain to be at its best, which might mean feeding it the food it has selected for. But the details of this elude me and for all I know I'm just perpetuating a myth. Is there a Debra Wink bat signal I can shine somewhere on this website?
The explanation is chemical, no biological. To avoid what they call I believe a "starch attack" rye dough needs to reach a certain level of acidity. It is much easier to achieve with a rye sour.
Not only have I read about that, but I've fallen victim to it...even with a 100% rye starter. I'll have to re-read my copy of The Rye Baker. Thanks for the lead!
There are plenty of formulas for 100% rye bread and I suppose that, if I were making this bread, I would want to use a purely 100% rye starter. I don't make these types of bread but a quick review of web shows two thing; either the bread is baked in a pan (dense and square) or freely baked on a stone without a form (dense and flat).
Most rye bread that I have seen relies on a strong leavening agent and a strong gluten structure. To me this means wheat flour in one form or another. If there is wheat flour in the formula I don't see a problem with a small amount of wheat flour in the starter.
As to the "starch attack" from what I read this is a factor with amylase and available starch. Both rye and wheat have amylase and starch. The more acidic the formula the less likely the attack. Maybe the addition of a small amount of ascorbic acid would help here.
Yes, Stan Grinsberg, Debra Wink or our other expert contributors might offer some more established knowledge here.