Yeast is one of the most important ingredients when making pizza dough as it’s what makes the dough rise and adds those amazing bubbles to your bread and your crust. The basic ingredients for all pizza doughs are flour, yeast, water, salt, and olive oil.
How Does Yeast Work?
Yeast is a living organism. It is, in fact, a fungus and yeast “digests” certain sugars.
Incidentally, that’s why it’s recommended that you add sugar when proofing the yeast. (Proofing is a test to make sure the yeast is active, i.e. it’s still alive and able to grow). The yeast needs sugar in order to grow. So, it’s also a good idea to add some sugar to your flour mixture to speed up the growth process. When you mix the yeast with your flour mixture, the yeast also feeds on the sugars present in the flour itself.
As the yeast digests the sugars, it releases carbon dioxide causing the dough to fill up with “air” and rise. When you bake the dough, it seals itself and locks the pockets of carbon dioxide in. These pockets of air are, of course, what make the dough light and fluffy.
It’s important to note that temperature has a significant impact on the health and growth of yeast. Temperatures between 80ºF/27ºC and 115ºF/46ºC are ideal for leavening. However, it’s important to keep the temperature below 120ºF/49ºC because, beyond that temperature, yeast dies and your dough will cease to rise.
Knowing how yeast works, you can control the texture of your dough. For example, at a dough temperature around 86ºF/30ºC, the yeast will grow more slowly and produce an evenly risen dough. At temperatures closer to 115ºF/46ºC the yeast grows faster and produces large air pockets.
Using more yeast will produce a fluffier dough. Less yeast will give you a thinner, denser dough.
You can also control the density of the dough through time. The longer you allow the yeast to grow and multiply, the more the dough will rise. With this in mind you can use a very small amount of yeast and let the dough proof for 24 hours which many say gives a more complex taste.
Flour with a high gluten content (12% protein or higher) will promote the growth of yeast and is great for making thin, light, cracker-textured crust.
Where Does Yeast Come From?
Baker’s yeast is a fungus (Saccharomyces cerevisiae). The fungus grows by “digesting” certain sugars and converting them to carbon dioxide.
Yeast was probably originally taken from the skins of grapes. You can see yeast by looking at the the thin white film on the skins of dark-colored fruits like plums. However, the yeast you’re using for your baking was probably cultivated in a lab. Labs prepare “food” for the fungus by straining water used to boil potatoes and combining the potato water with corn sugar.
How to Proof Yeast
Whether you need to proof your yeast depends on the type you have.
Fresh yeast is available in small blocks, is ‘fresh’, needing to be refrigerated and will need to be proofed.
There is also instant yeast which come in two varieties: Active Dry Yeast and Instant Dried Yeast which is also known as fast-rising or rapid-rise. Active dry yeast will need to be proofed where as instant dry yeast can just be added straight into your mixture.
Proofing yeast before mixing it with your dough ensures that the yeast is still active, i.e. alive and kickin’. You’ll know your yeast has passed the test if it foams up after about 5-10 minutes. If, however, it just sits there like a bump on a log, then it’s time to begin the mourning process because your yeast is dead.
So, here’s how to proof your yeast.
- First, heat 1/4 cup (60ml) water to 110ºF/43ºC which is roughly speaking, warmer than lukewarm, but not so warm that it feels hot to the touch. You should be able to comfortably put your finger in it. If you were to drink it, you wouldn’t burn your tongue. This is where a thermometer can come in handy.
- Next, dissolve 1 teaspoon sugar in the water.
- Add 1 packet of active dry yeast (2¼ tsp or 7 grams) to the water mixture. Stir.
- Let the mixture sit for 5-10 minutes.
If the mixture is foamy, you’re in business. Otherwise, you’ll have to throw it out and try a different batch of yeast.