Wild Yeast in the Air

Is it true there is "wild yeast" that is flying around in our air that might drop into our dough if we let it stand?

Does the Chicago area have any certain type of "wild yeast", and does this vary from one part of the country to another?

Sure there are wild yeasts in the air. Just ask the brewers in Belgium, or the sourdough makers in San Francisco. I've let a loose mixture of water and flour sit out, and after a few days was able to use it to make bread (although it rose much more slowly than with commercial yeast).

As far as what the varieties of yeasts are in the air around here, I'd have to defer to someone with more microbial experience.

I grew a starter from nothing more than flour, water and crushed grapes (a la Nancy Silverton) and for years, it produced some of the best loaves I'd ever eaten. Getting it off the ground required a fairly intense feeding regimen but eventually I ramped it up (you gradually increase the quantities during the initial 2-week period) to the point where I was able to easily bake with the starter and no other leavening agent. Based on my experience, the wild yeasts in the Deerfield area were excellent, plentiful and lent themselves very well to bread-baking.

In general, naturally-raised breads do take a bit longer to rise than those that use commercial yeast but the benefits are significant. The longer bread takes to rise, the more flavor it has. This is because lactic acid, which is a by-product of yeast feeding, is an important part of what creates the complex flavor in naturally-raised breads. The slower the rise (or the longer the yeast feed), the more lactic is created and the better the resulting flavor will be. With commercial yeast, the rise is faster and the resulting flavor is usually fairly simple.

If you're interested in growing a starter and baking breads with it, I highly suggest that you check out Breads from the La Brea Bakery by Nancy Silverton. While there are certainly other excellent resources on the subject that are available, if you follow the instructions in this book, you will be handsomely rewarded for your efforts and you'll learn a ton about the craft in the process.

=R=

Thanks everyone. I'll check out your suggestions.

The basic sourdough recipe in Nancy Silverton's book is the best I've found.

I'll quibble with her method for beginning a starter, though. There are yeasts in the air, but there are many more in the flour itself. When you grow a starter from scratch, you don't pull the yeasts from the air nor from grapes nor from potatoes (another common technique). Generally the yeast already in the flour comes to dominate the starter.

Here is a great tutorial on sourdough bread: http://forums.egullet.org/index.php?showtopic=27634

At the end of Jack's bread recipe he advocates baking the bread right out of the fridge. After a lot of experimentation, I get much better results from giving the bread a good 4-hour rise before baking.

Yes, wild yeasts vary from one area to another. San Francisco sourdough is unique to that area because of the specific yeast there.

If you do make your own starter, you want to do more than mix flour and water, and let it sit. The starter has to be fed. I think Silverton's method is crazy for a home baker. I get much better results a variation on Jack's method in the eGullet lesson. Another good reference is the book by the Berkeley Cheese Board, "The Cheese Board Collective Works".

Not just in the air and the flour, but the grapes themselves are generally coated with it. Any white dustiness you see to the skins is the "noble rot" -- the yeast. Fresh grapes pressed for juice will ferment if not otherwise preserved. Welch, a teetotaller, developed the technique for creating essentially pasteurized grape juice, and created a food empire from there.

This is a good read whether you agree with her or not (I agree with her on all counts):

http://www.wildyeastblog.com/2008/04/22 ... ries-myth/

It is easy to capture microbes from the air, flour, fruits, your hands, sneezing, coughing, etc. But isn't always so easy to capture a culture that contains a mixture of yeast and bacteria that has adequate leavening power, a desirable flavor, and is robust enough to battle contamination from other organisms over the long run. When I lived in San Francisco I captured a semi-sour strain with great flavor but not much leavening power so I always had to give it a commercial yeast boost.

A few years ago I discovered the amazing starters from http://www.sourdo.com. The initial activation can be a bit tricky, but the resulting cultures are really amazing and have changed my bread-making entirely. Some of these starters come from bakeries that have used them for hundreds of years. I NEVER use commercial yeast any more and wouldn't ever consider capturing wild native cultures ever again.

I second the recommendation for Silverton's book. However, since the the way I maintain my cultures differs significantly from hers, I always modify her recipes, but try to maintain the original proportions. Her bagel recipe forms the basis for one of my successful breads.

Bill/SFNM

A few years ago I discovered the amazing starters from http://www.sourdo.com. The initial activation can be a bit tricky, but the resulting cultures are really amazing and have changed my bread-making entirely. Some of these starters come from bakeries that have used them for hundreds of years. I NEVER use commercial yeast any more and wouldn't ever consider capturing wild native cultures ever again.

I bake a fair amount of naturally leavened bread at certain times of year and I strongly endorse getting a starter from sourdo.com, even though it doesn't seem as attractive as capturing one on your own. I've used the Silverton grapes method as well as others and never came up with a really strong starter or one which would survive weeks in the fridge without being refreshed. The sourdo ones are great.

JoelF wrote: Any white dustiness you see to the skins is the "noble rot" -- the yeast.

I thought that Botrytis cinerea was a fungus not a yeast?

I think, technically, yeasts are considered a type of fungus.

Darren72 wrote:Generally the yeast already in the flour comes to dominate the starter.

This is what I've always understood to be the case--that when most people talk about capturing wild yeasts in the air for their sourdough starter, it really is almost always the yeast already in the flour that takes over. I suppose one can microwave the flour, killing any already present wild yeasts in it, and see what happens. Then, you should be cultivating only the wild yeasts that are present in your environment.

Botrytis--noble rot--does not ferment anything. When the weather is warm, it rots grapes in an instant. When the weather is cooler, and the grapes have thick skins (think Riesling, Chenin blanc, etc.), the mold colonizes the skin, and sinks "wells" into the grape flesh to provide it moisture. As the grape dries out, its effective sugar content rises; moreover, the mold adds some flavor of its own.

Very few winemakers use "natural" yeasts, they're waaay too variable. Rather, they buy cultured yeast strains--many of which began life as local wild populations--and induce fermentations that way.

Not all that disanalogous to what Bill/SFNM is describing as sourdo's method.

Geo

Yes, there is yeast in the air and yes ,there is yeast in some kinds of flour and your right noble rot is a fungus but the white ash on grapes and plums ,juniper berries ,apples (harder to see)IS wild yeast.

The the skinny on it is if you make a sour from just flour the endo sperm is removed thats where to yeast would have been. So when you make those kind of flour and water mixture your at the mercy of what ever is floating around and you most allway get some kind of sour. The reason for this is that it kind of a survial of the fittest bactria and mold as well as yeasts and fungus are all trying to grow at the same time until one of them over power the others. Sometime it great San Fran Yummy other time eww yuck-oo.

So you want to give the little yeastys a fighting chance so they can grow and crowed out any undesirable bad smelling and tasting competors.


You can do this with stone ground rye. It has an abundance of natural yeastys.
or plums ,apples, grapes or juniper berries from the wild.

In a small jar mix equal parts of the rye and water and put the top on loosly tight enough to keep out other free floatys but not so tight that the gas can't escape.
Two or three day it should be foaming away. It alive!!

The same goes for the others but you want to use organic fruit. You squash it , grate it, or just add it to a flour mixture. Again the equal water equal flour and in a few day it will be bubbing away.

Once ya got your yeasts your gonna add 1/2 cup water and 1/2 cup flour till you have a cup to use and 1/2 to save. Then make your recipe.

Normandy Apple Bread from the apple.

Sourdough Rye from the rye.

Peasant bread from the grapes.

the juniper is a fun one i like to make a Caraway rye with it.

Most of these need to rise at least overnight but you can add a teaspoon of instant yeast for a more typically rising.

With your starter the 1/2 cup you have left over feed it with 1/4 cup water and 1/4 cup flour let it set till it starts to bubble. Seal the jar and put it the refrig. You can store it for about 2 week but after that ya got a feed again.

This is a living thing so as you use the taste is going to change sometime for the good sometime for the bad. If at anytime you see colors pink, green throw it away.

I've done this on 33 gallon garbage can scale for my bakery. I love the taste and texture of real honest to goodness nothing but flour water and salt bread. It an art that I love.

Hope this helps
Chef Bear Italia
Michael Zito