Banana-scented sourdough?

[backwoodschemist]

Hi SednaBoo,

Yes, off flavors and smells are common with wild ferments. You probably had a new organism move into your culture. If you don't like it, dump it and start over, otherwise you're probably stuck with it.

Beer is quite prone to off flavors and odors, butterscotch is a common off flavor.

Different locations have different dominant wild beasties, supposedly moving San Francisco Sour dough to NY will cause the flavor to change within a few weeks to months as the new flora takes over. I don't know how true that is, but it is possible.

I did some our dough last week and the second loaf off the same starter had more sour character and a really nice smell to it. The change occurred within only a few hours, kind of surprising.

BWC

[DT611]

I would definitely not call it an "off flavor." It was pretty awesome actually. I did some digging into what those cats at MIT did, and it seems thatthe gene they used to create the banana-scent was from Saccharomyces cerevisiae, which is a common critter in ferments. I think E. coli can do the trick too, which is to convert isoamyl alcohol to isoamyl acetate, the latter making the smell.

Since i'm a molecular biologist, i was thinking of possibly engineering a batch of sourdough to be banana flavored. Or wintergreen. I think it will be tricky to do and make it safe and stable to release into the wild. Since it is just amplifying something that they critters already do naturally, I don't think it would be dangerous or anything. What do all of you people think? Would you eat GM sourdough that tasted like bananas?

You're a molecular biologist? Cool!
Eating "GM sourdough" that tasted like a banana would be unusual to others(I think).
However, I think tasting something new is better than just "looking" at other people eating something new. :)

[Tim Hall]

Lots of strains of yeast (especially brewer's yeast) will produce isoamyl acetate. Very common component of fruity Belgian-type beer.

My vote for GM banana-flavor would be NO. Nature can do it all without us breaking her down and abstracting her.

If you want to experiment with getting natural banana aroma, I'd suggest experimenting with adding a little Belgian Tripel yeast to your sourdough starter and fermenting slightly warmer than normal.

FYI this is a very common ester in nature. For bees it's "alarm" pheromone. For the small hive beetle, an enemy to bees, it's an attractant. The small hive beetle carries a species of yeast that produces the ester, and they inoculate honey in the hive, making their own banana brew.

[elektrogeist]

Banana-like smell and flavor I have encountered before in fermenting a Belgian White, actually. And yes, certain esters formed via specific saccharomyces are behind it. If I'm not mistaken, the yeast used was Wyeast strain 3463 "Forbidden Fruit"
I've used part of leftover yeast cakes from brewing as bread yeast before, with sometimes very delicious results-no point in letting quality yeast culture go to waste! =) Too bad I never do lambic, wouldn't sour-lambic bread be interesting?