SC - non-member submission - re - must

[Decker, Terry D.]

> Yup. And there are plenty of references to leavening with beer barm.
> (Inexplicably, these are mostly redacted by using beer and some form of
> leaven other than yeast. I don't understand this.)
> 
Not beer, ale.  Saccharomyces cerivisiae is top fermenting and was dipped
from the active ale pot to be used as leaven for bread.  Variants of S.
cerevisiae are still used as bread yeast.  Ale has been used for this
purpose from the Vandals forward (see Pliny).

Since the Romans were not ale drinkers, they used grape must as a leaven,
until the Greeks and Germanic tribesmen took over baking in the Empire.

S. carlbergensis is beer yeast and is bottom fermenting.  It can be used as
a leaven, but is not normally used in this manner.

For most modern store-bought brews, the yeast is dead or dormant.
Re-creations tend to use a bottle of brew for the flavor and baker's yeast
(S. cerivisae) for the ferment.

> Does anybody have any reason to believe that period breads were formed by
> using a new sponge every time, and letting it sit until it bubbled
> (usually several days)?
> Otherwise, I would assume that either beer barm or a starter from the last
> batch was used in the dough, and that the sponge (a slurry of water and
> flour, with yeast added-- the first rise step in making sourdough bread,
> nowadays) would be left to rise again for about 12 hours or so, rather
> than the several days it would take to ferment it from natural intrusions
> of yeast.
> 
> Jadwiga Zajaczkowa, mka Jennifer Heise	      
> 
The two common methods of leavening bread in period were ale barm and
sourdough. The exisiting recipes suggest that ale barm was used directly
with minimal rise time.  Post-period recipes describe methods of drying and
storing yeast from ale barm.

Sourdough was used in the sponge method.  A portion of the dough would be
recovered from each baking to start the next batch of dough.  The original
starter would have been made from flour and water and allowed to ferment
from wild yeast rather than having yeast added to it.  Traditionalists still
use this method.

The sponge made with yeast added is a modern approximation of the
traditional sourdough method.  It is common to use all of the yeast sponge
each time, because S. cerevisiae does not do well in highly acidic
environment of a true sourdough.
 
BTW, France at one time had a law that bread could only be made via the
sourdough method, until they needed yeast to make those airy baguettes, and
lo and behold, the law was repealed.

Bear