why rye bread in beet kvass?

Have been meaning to ask this for a while. Beet kvass is traditionally made with a slice of dried rye bread. My polish grandmother says that's how it's always been made. She wasn't convinced that it would work very well without it. Was wondering whether folks here have found this to be true?

My speculation as to its function is that it may be there to help the bacteria get a foothold by providing more easily digestible sugars than are in the beet. Just an idea though, would be interested to hear any others.

However I have trouble digesting any grains whatsoever so was hoping to go without, but wanted to ask around before trying it. Also perhaps it could be substituted for something else? Can't think what though.

Apparently I have never made traditional Polish beet kvass because I have never made it with a slice of dried rye bread.
I assume they used the bread to introduce micro-organisms, and maybe provide easily digestible surgars like you said. But beets have plenty of simple sugars in them anyway. So, I honestly don't know.

Anyway, you can do with out. I make beet kvass all the time, it nearly always turns out delicious, and I never use the bread. Just chop beets, and some salt, add some water, and wait a few days.

The "sugar" in bread is going to be tied together in long chains of starch, so it won't actually be as easily accessible to the microorganisms as the beet sugar. And whatever yeasts or bacteria that were present in the fermentation of the bread dough will be killed by the baking. (Certainly there will be an eventual recolonization of the bread, but that is often molds before bacteria.)

Perhaps what the bread adds is protein. I'm not sure how much protein is in beets. You mentioned you have trouble digesting grains, and those proteins are often a source of irritation, but that gives me two thoughts:

1) maybe the organisms in the kvass will help digest them *for* you.

2) try adding a grain that does agree with you: rice? quinoa?

Just a different perspective... My thought was what are beets doing in kvass?

My experience is with the Russian stuff, made from bread.

So, I did an experiment with my polish mother, who, by the way, never uses salt (I also tried using salt, in the quantities specified in Nourishing Traditions, and found that it did not ferment for me)

We made up one batch of beet kvass with a slice of rye bread and another without, kept them next to each other, and found the following:

After 3 days, bread batch is sourer than the non bread batch.

Also, bread batch produces a pleasant looking pinkish froth, whereas the non bread batch froth is brown, which suggests more oxidation.

Anyone care to speculate as to why this might be so?

Adam Ormes wrote:

Anyone care to speculate as to why this might be so?

Different strains of yeast (or different combinations of strains) doing the fermentation?

The more important question is which one tastes the best? Smacznego!

Well, I'd say that the bread one tastes better.

As for different strains of yeast developing, presumably this would happen through selection by environment, unless there are yeasts that establish themselves on the bread after baking - the traditional thing is to use some stale bread with a crust on.

At the same time I've been wondering whether this might be an example of something Sandor Katz describes in his Art of Fermentation is that the DNA profile of bacteria can be influenced by the presence of dead bodies of other bacteria. I have yet to fully comprehend what he writes, but this may also be happening here...

Smacznego, indeed! Traditional borsch is made with beet kvass, plus some salt, honey, pepper, nice with a bit of allspice and pepper too. As with miso soup, best to heat minimally.