Although some people think there are only two yeast types: dry and fresh, there are actually three types available around the world. But which one do you need?
Have you ever thought what yeast actually is? The answer might surprise you: it's a small plant-like microorganism classified as a fungus, that exists all around us: in soil, on plants, and even in the air. Yeast originated hundreds of millions of years ago, and 1,500 species are currently identified. The most common one is Saccharomyces cerevisiae – the one that you use in baking as a leavening agent.
How does leavening happen? Well, yeast eats the existing sugars in the flour and expels the carbon dioxide in the process. This gas makes the dough rise, while it forms pockets or bubbles. Now that you know yeast is ‘alive’, don’t worry! When you bake the dough, the yeast dies and the air bubbles give the bread a soft and spongy texture.
3 yeast types to bake with
Until the 1800’s, all bread was baked with a sourdough culture which is no more and no less than yeast trapped in a paste of flour and water. In 1825, they developed a method to remove the liquid so the yeast could be prepared as solid blocks. In 1872, we developed a manufacturing process to create granulated yeast.
1. Fresh yeast
Fresh yeast is soft, solid, beige in color, and you can easily crumble it with your hands. It’s shaped in small, foil-wrapped cubes, but it’s also available in a larger-block form for professional bakers.
To use fresh yeast, crumble it into small pieces. Then mix it into a pre-dough – together with flour, warm water, and sugar – that needs to ferment for about 20 minutes before you can add it to the dough. Fresh yeast is great in breads that need a long and slow rising time, as it activates more quickly than dried yeast and also stays active for a longer period of time.
Because it has a short shelf life (about two weeks) and it needs to be refrigerated, it’s hard to find it in the USA because most of the grocery stores stopped carrying it. Even some fresh yeast producers limit their sales area. If you want to use fresh yeast, try to find a grocery store that sells European products. Even if fresh yeast is not easily found in the US stores, this is the default yeast for many European countries.
2. Active dry yeast
Most of the recipes (especially American ones) usually call for dry yeast, which can be active dry or instant. Active dry yeast was created during World War II for the United States’ armed forces because it doesn’t require refrigeration and has a longer shelf-life and better temperature tolerance than fresh yeast. It can be stored at room temperature for a year.
From all yeast types, this is the one most available in the United States. You can buy individual packets or small jars of active dry yeast, that consist of round small granules. Active dry yeast needs to be dissolved in water before use. Then, add it to the rest of the ingredients.
3. Instant yeast
Instant yeast is one of the yeast types also known as Fast-Rising, Rapid-Rise, Quick Rise, or Bread Machine Yeast. Instant yeast consists of very small granules, that resemble a powder. Because of its fine particles, it dissolves faster and activates quickly in the dough.
To use it, you don’t need to dissolve it in water. All you have to do is to mix it straight into the dry ingredients. Its fine texture helps absorb moisture faster, rapidly converting starch and sugars to carbon dioxide, which goes to quickly form tiny bubbles that expand the dough. That’s why it’s called ‘instant’.
Which one should you choose?
The three types of yeast can be used interchangeably. If your recipe calls for dry yeast and you have fresh yeast in your refrigerator, use this ratio: 2 1/4 teaspoons of dry active or instant yeast granules to 2/3 ounce (19 grams) of fresh yeast.
The advantage of the instant yeast is that the rising time is half that of the active dry (that needs extra 10 to 15 minutes for the rise time), and it only needs one rising. That’s why you can skip the first rise of the dough and shape the bread loaves right after kneading.
Some claim that bread tastes better or sweeter with fresh yeast than dried. Others say that the flavor is the same. We think that, if you respect the ratio – and that means no more or less yeast than your recipe asks – the taste will be just fine. It may be just a matter of familiarity.
In terms of purity, fresh yeast and active dry yeast are 100 percent yeast. Instant yeast is not 100 percent yeast because it contains additives.
While for most Europeans fresh yeast is the regular kind – at least until a few years ago –, for Americans the yeast types that matter are the dried ones. And the only reason is its availability in stores. In some parts of the world, fresh yeast is sold everywhere, but in others, including the UK, it is hard to find.
So, if you’re wondering which one of the three yeast types to use, there's no right answer! Use what you can get, respect the quantities, and you’ll have amazing breads!
Here are 3 bread recipes you can make using yeast: