Where does the yeast for your homemade pizza come from and does it even matter?

Somebody recently asked, “Where do you get yeast, and which one is best for pizza dough?” And the first thing I thought was, Well duh. You get yeast from the air.
 
That, of course, is not the first answer everyone else has. They will likely say, “Well duh. You get yeast from the supermarket.”
 
Which is not untrue. And that was not a double negative. Or was it? I think, yeah. No. Whatever.
 
And just by the way, if you’re reading this and you happen to be a mycologist or a fermentation specialist, know that I’m speaking as a layman who’s fully aware that you can tell me I’m speaking out of my pizza hole. So be it. I will publish any required corrections to my non-scientific blather, and I thank you in advance for your participation.

Anyway, yes, you can get yeast from the air. You can leave a container of flour and water open to the air, and it will eventually become populated by so-called wild yeast.
 
It takes about a week or so for the water and flour mixture to begin bubbling with signs of life. It’ll look something like this:

You can then use that bubbly flour and water mixture to create a wild-yeast sourdough starter. And that can lead (if you so choose) to a wild-yeast pizza dough.
 
And then, you can make a wild-yeast pizza that looks like this:

​In other words, you make a pizza that looks indistinguishable from any other really good homemade pizza.

 
I have great respect for sourdough geeks.

Personally, I have too much else going on in my life to worry about keeping my sourdough starter alive. Collecting yeast from the air and making sourdough is not the most convenient pursuit. I’ve done it and I will do it again. Just not right this minute.
 
(By the way, some people say the yeast is already in the flour. Who am I to argue? Maybe it’s in the flour as well as in the air.)
 
 
The other place yeast comes from is far easier and more convenient: the supermarket. 
 
Commercial yeast is the product of industrial fermentation. To be crazy simple about it, yeast starts out wet, is sometimes dried, and ends up in a foil packet or a glass jar (or sometimes a vacuum-sealed brick) at the local supermarket. 

Before it gets to the supermarket, that yeast is made in a factory. Think giant metal tanks, pipes, valves, wheels, centrifuges, and other industrial hardware.

The factory grows yeast from a culture in a tube and eventually ends up with yeast by the truckload in various commercially available forms. It is alive!


Most supermarkets almost always carry active dry yeast. 
 
Active Dry Yeast (or ADY) is a product of the early 20th century, developed for the US Army by Fleischmann’s circa World War I. It still works, and it remains the standard today for US Army recipes.

But to be opinionated about it, it seems like an outdated product.
 
My theory as a non-scientific yeast consumer but a longtime student of marketing and human behavior?
 
ADY remains commercially available because people just do not enjoy change. A lot of people still want to use it. Why?
 
 
“That’s how my grandmother did it, so it’s better!”
 
I suspect a lot of the things the proverbial grandmother did in the kitchen were done because back then, that was the only way to do them.
 
In my grandmother’s time, it was either wild yeast or fresh yeast. My grandmother also had to milk goats, didn’t cook, worked in a bank, and never went to doctors.
 
How many of those other things should I cling to because of the importance of tradition? “Honey, we need to get some goats and I’m canceling the health insurance!”
 
 
Sometimes, another supermarket option is fresh yeast, also known as “cake yeast,” “compressed yeast” or “wet yeast,” and is a creature that requires care. 
 
With a shelf life of four to six weeks, you gotta use this stuff in a hurry.
 
Plus, if you mail-order fresh yeast, you’re at the mercy of the inexact science of climate-controlled delivery and logistics. (See also: disgruntled Prime driver who hurls that carton labeled "grandma's fine crystal - fragile" onto your brick patio because he's under pressure to meet an unrealistic delivery schedule.)
 
If you want to see the results of that dynamic, just go to Amazon, search "fresh yeast," and read all the one-star reviews of yeast that costs $7.00 an ounce, minimum purchase 12 ounces. It’s pissed-off bakers’ central over there.
 
 
And at the end of the day, as with wild-yeast sourdough, you get to claim bragging rights for using fresh yeast.
 
What's the difference in your pizza?

"You used fresh yeast, dude! '

That's it. 

I can’t guarantee you’re going to find it any more flavorful than a direct-leavened dough made with IDY and cold fermented for 72 hours.
 
For me, the real secret is in always using less yeast and doing an extended cold fermentation. That’s how the complex flavors in your pizza dough are guaranteed to happen.
 
But a lot of people love to hang their hats on “I use fresh yeast!” Far be it from me to diminish either their fun or their commitment to raising the bar. If it helps them create a mystique, so be it. At least they’re not bragging about the water they use.
 
 
The lazy man inside me believes most convenient yeast product is the more contemporary Instant Dry Yeast (IDY).
 
The successor to active dry yeast, IDY doesn’t require “activation” the way ADY does. You just measure it, toss it into the dry ingredients, and go along your merry way.
 
I was so very happy the day I discovered the existence of IDY. That whole step of throwing yeast into a bowl of water always annoyed me. I suspect it was the feeling of haphazardness about it.
 
Will it work? Will it come alive like a horror movie about reanimated microscopic corpses?
 
Or will I end up with a bowl of Dead Yeast Soup?
 
I am grateful for being able to eliminate from my life that little foil packet filled with thousands of tiny question marks.

And by the way, IDY is sometimes marketed as a "rapid rising" yeast, or "bread machine" yeast. A rose by any other name smells as yeasty. 
 
 
There is also a type of IDY out there called “Pizza Yeast.”
 
If it's pizza yeast, it MUST be better, right?

Save yourself!
 
I do not recommend it. It contains dough conditioners, which I find have a kind of faint chemical taste that smacks of frozen pizza. And yes, I have taken a bite of pizza made by somebody else and asked, "What happened? Are you using pizza yeast?" (They were.) 
 
If you’re going to the trouble of making homemade pizza, I encourage doing it the easiest way that tastes best: the instant yeast and the long ferment. The dough will condition itself and you'll end up with a great-tasting pizza. 
 
 
And whatever format of yeast you’re using to make pizza dough, know that you’re dancing with Saccharomyces cerevisiae. 
 
That’s a species of yeast more commonly referred to as brewer’s yeast or baker’s yeast.
 
Brewers don’t always use it these days. It depends on whether they're making a top-fermented ale or a bottom-fermented lager. The lager is made with S. cerevisiae's deviant cousin, S. pastorianus. 
 
I could go on to continue explaining all that. But why? It doesn't impact pizza dough. And I’d be more interested in explaining why oyster stouts don’t contain actual oysters. Unless they do. (How’s that for confusing?)
 
Bottom line: get your yeast wherever and however you can and in whatever form that works best for you. And be sure to give it time to do its job. That way, you’ll be a happy pizzamaker. Good luck!

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