Having puzzled to work out what was happening with the sluggishness of the doughs and sponges made with barm (yeast from the brewer), the experience made me think a lot about temperature. With the barm fermentation, 25C was necessary to get it moving.
Students will recall that I often stress the need for an awareness that it is not just the amount of yeast that you employ for fermentation, but the temperature at which you choose to conduct it. Cool dough is sluggish, hot dough simply makes bad bread which is crumbly and quick to stale.
Here is a chart in Celsius for your help:
Below 10 – retarding
11-18 – sluggish fermentation; sourdough happy but slow
19-22 – cool fermentation, measured and slow, keeps long sponges in check
23-24 – very satisfactory for European breads & sourdough; sponges and yeast breads happy, but will not ferment too briskly
25-27 – traditional temp for slow fermenting English white bread & sponges, suitable for strong flour; suitable for working barm doughs & sponges
28-30 – harmful to wheaten breads, too hot for good structure; rye, however, can just tolerate these higher temps that are basically regarded as too high
