January 31, 2022 - 7:36am
"Stronger" v. "Weaker" Flours and Fermentation durations
My German is poor so there's a lot I'm yet missing when reading original German sources. In investigating German flours and suitable substitutes here in the States, I get the impression of German bakers comparing flour strengths and the length of time that stronger flours can "handle" longer fermentations. The implication being, stronger US flours can handle longer times, whereas the relatively weaker German flours necessitate a shorter fermentation period.
I may have this all wrong. But does this ring a bell? If so, why? Gluten breakdown, extensibility requirements, in that vein?
Proteins are slowly denatured in acidic environments so if you are making a sourdough bread with a particularly long fermentation more of the gluten will break down over the course of the fermentation. This will be more of an issue if you had less gluten to start with. If you are baking with commercial yeast then as far as I know this shouldn't be too much of an issue.
Weak flour releases water as it ferments and has low fermentation tolerance. So you end up with a soupy dough with little structure.
Strong flour absorbs more water as it ferments and has good fermentation tolerance. It becomes dry and bouncy, even bucky as it ferments and can withstand several rises and punch downs.
Both can ferment for a long time but you must handle them differently. Basically , weak bread flours are defective flours and are not sold in North America. Here, even pastry flours will make good bread.
OK, that's interesting, thanks Mariana. I've been spending quite a bit of time with German bakers on various blogs and FB pages. Their flours are weak. Would you consider theirs basically "defective" flour, then, that they've had to learn to adapt to - namely, the norm seems to be a tremendous amount of preferment flour and sauerteig ratios, short bulk and proofing periods, at least relative to what I'm used to (partly I know their custom is to include a bit of cultured yeast)?
Paul, I baked with many wheat flours from Europe, including from the countries bordering with Germany, but not with German flours!
I would not say that bread and all-purpose flours from Finland, Norway, Switzerland, Poland, Belarus, Italy, etc. are weak, although they are not as strong as North American flours or flours from Hungary, Ukraine, Siberia.
They may be of average or below average strength, but not weak to the point of needing repair (additions of flour improvers). I assume that professional bakers, owners of small and large industrial bakeries, face those problems more than home bakers do, since flours in grocery stores are carefully selected to have a certain level of strength, satisfactory and idiot-proofed.
I have never had to bake with truly weak bread flours as my friends from other countries had when they bake with locally milled flours, so I only know from reading that historically the methods used were
(a) to mix a stiffer than necessary dough (because it becomes softer, moister, as it releases water with time),
(b) not to strive to develop gluten asap by kneading intensely, i.e. knead only to homogeneity initially, and
(c) use larger preferments (up to 70%PFF) and minimize the punch downs. I.e the final dough is allowed to rise to the maximum volume only once, but maybe slower.
Usually, though, the problem of the weak flour these days is solved much easier with flour and dough improvers and by mixing weak flours with strong flours, including vital gluten flour, to obtain a satisfactory level of water absorption, water retention, and fermentation tolerance.
Many thanks Mariana.