Interesting Factoid.. wild yeasts on raisins for brewing homebrew

[JonathanCline]

In reading a couple homebrew beer recipes, it turns out that some
recipes call for using random store-bought raisins in addition to a
commercial packet of yeast. The idea is that the wild yeasts
(Saccharomyces cerevisiae) on the raisins, which collect as the grapes
dry, will promote better starter culture for brewing. A quick
search pulls up a couple papers revealing the DIY-method (used circa
3000 BC), rather than buying "the modern kit" of purified yeast, is:
throw some raisins into some drinkable-food-type-media and make a
starter culture, then throw the culture into a big barrel of more-food-
type-media, wait for a long while and presto, wine or beer.
Previously I thought the old-school DIY was to rot some grains in an
open air barrel to collect some yeasts, though nomads carrying around
a supply of slightly-dirty raisins seems much more high-tech-
miniaturized, right?


Ref:

Evolution and Variation of the Yeast (Saccharomyces) Genome
Open access, http://genome.cshlp.org/content/10/4/403.full
doi: 10.1101/gr.10.4.403 Genome Res. 2000. 10: 403-409

"Lindegren, also one of the pioneers of yeast genetics, used a strain,
EM93, that had been isolated by Emil Mrak (Mortimer and Johnston
1986). This strain was found on rotting figs in Merced, California, in
1938 [...] Katz and Maytag (1991) have recently made beer using an
ancient Sumerian recipe. They state that yeast was inoculated into
the original fermentations by addition of grapes and raisins. They
also may have been introduced to the malt by the addition of some
fermenting wine. An alternative explanation is that insects such as
bees, wasps, or Drosophila landed on the malted grain and inoculated
it with yeast carried on their bodies. "


As for that last part.. yuck.


## Jonathan Cline
## jcl...@ieee.org
## Mobile: +1-805-617-0223
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[Kyle Stratis]

I don't see why not, this is, with some modifications, a general way
to grow most of the mushrooms.

[tedstertm]

The Belgians have a style of beer in which they allow it to cool in
the open air letting a cocktail of yeasts and bacteria ferment the
beer producing some really interesting flavors. I've also read that
Vikings had a family beer stick which contained the family yeast
strain and was used to stir the wort and inadvertently inoculated the
beer. Pretty coo article though

[Levi Morris]

In case anyone's curious, Belgian ales fermented in open air are known
as "Lambic" (and they're delicious to boot!).
As far as going for DIY yeast, I've read accounts of people making
wild-fermented beers in the home successfully, and many brewers
(including myself) keep yeast strains in the fridge for re-use.
The biggest issue with going the wild yeast route is going to be
product quality control; if all you want is many gallons of alcoholic
beverage, it'll work great, if you're attempting to recreate a certain
style you're going to want a pretty particular yeast strain so that
you get the necessary characteristics such as alcohol content,
flocculation, flavors produced, etc....

Another thing to keep in mind is that most beers that use wild yeast
strains also involve other organisms (Brettanomyces, Acetobacter,
Pediococcus, etc...) that contribute to the flavor profile by breaking
down, or providing precursors to, some of the yeast fermentation
products as well as adding their own chemicals.

If anyone's actually interested in brewing a wild beer, I'd highly
reccomend "Wild Brews" by Jeff Sparrow, it talks a lot about the
history, culture (belgian as well as bacterial...), and methods
involved.

[Simon Quellen Field]

The white film on grapes and plums that you get in the supermarket is yeast that
lives on the sugars that leak out of the thin skin of the fruit.  My home-grown plums
are covered with it.

My latest science fiction novel A Twisted Garden is now available in bookstores.

[Cathal Garvey]

Boingboing recently did an article on Sourdough breads, and how they're traditionally (and optimally) made with wild yeasts and bacteria derived from the air.

http://www.boingboing.net/2009/10/06/yeast-where-were-goi.html

2009/10/8 Simon Quellen Field <sfi...@scitoys.com>

--
letters.cunningprojects.com
twitter.com/onetruecathal
Kiva.org - Loans That Change Lives

[JonathanCline]

On Oct 8, 12:26 pm, Cathal Garvey <cathalgar...@gmail.com> wrote:
> Boingboing recently did an article on Sourdough breads, and how they're
> traditionally (and optimally) made with wild yeasts and bacteria derived
> from the air.
>
> http://www.boingboing.net/2009/10/06/yeast-where-were-goi.html

One comment on that post is interesting, on using grapes to start a
sourdough:

""Seriously: people who have a good sourdough going will almost always
be proud of it an willing to share. So that's the best way to get it.
There are bakers in France and Spain who are using sourdough cultures
started hundreds of years ago. They'll gladly give you a chunk if you
ask. (although I doubt they'll send some to Japan). But if you really
want to start one yourself, and don't want to do the trial and error
thing to get the right yeasts and bacteria, here's a tip: buy some
nice, ripe, organic grapes and squeeze them into the starter dough in
stead of water. Without washing them of course. Your first dough will
contain grape skins and seeds but that doesn't matter: the first steps
of getting a good dough started involve a lot of adding flour and
throwing away dough. By the time your dough will be ready to bake,
most of them will be gone. The grapes must be organic: non-organically
grown grapes are covered in a thick layer of pesticides. ""


I also assumed that such an "open air" or random-fruit-started culture
would be more bad than good (statisticaly), although the article
states: "The good news: An unfortunate starter--no matter how funky--
isn't likely to make you sick. The bad news: No matter how experienced
you get, making starter remains more art than science." Very bad for
standardization & quality control!

> 2009/10/8 Simon Quellen Field <sfi...@scitoys.com>
>
> > The white film on grapes and plums that you get in the supermarket is yeast
> > that
> > lives on the sugars that leak out of the thin skin of the fruit.  My
> > home-grown plums
> > are covered with it.

Wait, I thought that white film was a government plot for population
mind control! Just kidding.

Seriously though, with some pharmacy-bought "pure" probiotics fetching
upwards of $50 per bottle ($2 per pill per day), how's eating a whole
lot of (farmer's market) raisins (or grapes/plums/etc) instead? If I
live in Asia again for an extended period, the first thing I'll do is
eat a bunch of dried fruit (and their dried fruit has a ton of flies
all over it while drying, to be sure!) and raw mushrooms, maybe that
would eliminate some of the dietary problems, as it plants a huge dose
of local microbes into my system.

[Cathal Garvey]

Although oral tolerance induced by eating the yeasts may put one at risk of developing thrush.
Caveat cenator! :)

2009/10/9 JonathanCline <jnc...@gmail.com>

[Daniel C.]

On Thu, Oct 8, 2009 at 6:33 AM, tedstertm <teds...@gmail.com> wrote:
> I've also read that Vikings had a family beer stick which contained the
> family yeast strain

As an aside, "viking" refers to a profession, not a nationality. (I
get into this discussion on a semi-regular basis, primarily after
informing someone that my ancestors are Scottish vikings.)

-Dan

[Cathal Garvey]

Mine too! Well, Norwegian-come-Irish. And I'm not sure which King Auliffe I claim heritage from. I prefer the effective, more famous one.