Leaven bleg.

So I was reading the Exodus/Passover account this morning and it occurred to me to wonder: 

What kind of leaven did the Israelites in Egypt use, anyway?  I mean, obviously (I think) it would be a naturally occuring yeast, but how did they work with it?  Was it like a sourdough, where you use some of the last batch to leaven the next batch?   Or was it fresh leavening added to every batch?   

I'm just wondering, exactly what did they have to do differently, in terms of recipe, when they were commanded not to leaven their bread.

Was the process changed much when, many generations later and in a different land, the Jews were keeping the Passover feast in the time of Christ?

Comments

[Meira Voirdire]

You might check ou.org (orthodox jewish site) to see what the prohibitions during passover are to see if that would lend a clue. I can promise you this, though: the answer is out there, lol.

[DarwinCatholic]

This is guessing, but I would assume that ancient bread leavening was done on the same principle as much of ancient beer brewing: you always keep some going.

So instead of having a starter as in sourdough, you'd take 80% of the dough, bake it, then add more flour and water to bring it back up to a full batch of dough, kneed, and set aside over night again.

A number of modern artisan breads still use an old dough technique to allow the flour more time to break down into sugars digestible to the yeast and provide a sweeter, nuttier taste with the slightly caramelized bubbles inside.

[alicia]

A piece of leaven (yeasted dough) much like sourdough was kept from breadmaking to breadmaking. But once a year, it was all destroyed, eliminated, burnt and swept out. After Passover, the housewife would set out moistened flour and wait and pray that God would send a good yeast strain down from Heaven so that she would have leaven for the next year! So getting rid of all the leaven was an act of tremendous faith, that God would send more leaven for the next year's baking.

[alicia]

OH, and to make unleavened bread they were required to bake the bread within a very short time (like minutes) of mixing the flour and the water, to prevent even the beginnings of fermentation. Eventually, the discipline was such even wheat flour was not kept in the house, only meal made from the unleavened bread, lest yeast accidentally find its way into to the flour. If you look at the boxes of Kosher for Passover cake mix, you will see that they use matzoh meal and potato starch (not flour) and use eggs, not baking powder or other added leavening, to keep them from being totally dense. RIght now, you will find the display of Kosher items set up as a separate 'pile' at the supermarket - they must be kept separate from all the other food stuffs or they will become tref.
And other fermented/fermentable beverages must be processed to be sure that no further fermentation can occur. Kosher wine is as sweet as it it because the added sugar inhibits further fermentation (to vinegar).