Although the name Saccharomyces cerevisiae might sound ominous, it’s simply the name of the organism that makes our bread rise. But you won’t see that scientific name on packets of yeast at the supermarket. Instead, you’ll see terms like active dry yeast, instant yeast, even fresh yeast. Which one should you bake with? And how do they work? You can make great bread with all types of yeast, but here are my tips and suggestions.
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What is yeast?
I won’t delve into biology too much, but yeast, like us, is happy when it has food, water, oxygen, and a warm cozy environment. When yeast is happy, it begins to ferment. One by-product of this fermentation is carbon dioxide gas. In bread, this gas gets trapped in bubbles of gluten, causing bread to expand and rise up. We have to work with our microscopic colleagues to get great bread. Let’s learn more about who we can hire to help us bake great loaves.
Active dry yeast
Most American bakers are familiar with the packets of active dry yeast on their grocer’s shelves since Fleischmann’s first produced this product in the 1940s. Most recipes call for active dry yeast to be dissolved in warm water or milk, sometimes with a bit of sugar added. You wait five to ten minutes, and then the yeast “proves” it’s alive by foaming up a bit.
Some people say that active dry yeast is the easiest to find at the store, but I see instant yeast on the shelf next to the active dry yeast at all of my local groceries. When using active dry yeast, always note the expiration date — expired yeast will not rise to the occasion. In my experience, you need to use about 25 percent more active dry yeast compared with instant yeast, but you have to dissolve and proof the active dry yeast first. When I started making bread, I used active dry yeast, and my bread came out of the oven much denser than I wanted. My success rate rose when I switched to instant yeast.
Instant yeast
Instant yeast is my preferred commercial yeast, and the one many of the home bread bakers II know opt for as well. The LeSaffre company started selling instant yeast in the 1970s, which means it is a newer product than active dry yeast. I find that it is less expensive (per ounce), works faster, and is the most reliable. You do not have to proof or dissolve the yeast in liquid, and it comes in smaller granules than active dry yeast. Simply mix the yeast into your flour and then add the liquid ingredients. I suggest buying a large vacuum-sealed package of instant yeast from a quality brand, like SAF. After you open it, keep it in an airtight container in your freezer. I’ve had frozen instant yeast last as long as two years. You can add it to your dough straight from the freezer. If you have a recipe that calls for active dry yeast, don’t fret. You can swap in instant yeast; just reduce the amount of yeast by 25 percent.
Fresh yeast
Fresh yeast is sold as a brick of compressed fresh yeast cells. In my experience, dough made with fresh yeast rises the fastest of the three types of commercial yeast. Many European bread recipes call for fresh yeast. I never understood why until I made my Christmas Stollen. I didn’t find any Stollen recipes that reminded me of the Stollen I’d had in the past. When I translated recipes for Dresdner Stollen from German, and they all called for fresh yeast. After developing the recipe to get one I liked, I wondered if instant yeast would work just as well. I made two batches, one with fresh yeast and one with my go-to instant yeast. Although Stollen is a rich, dense bread to begin with, my loaf made with fresh yeast rose much more than the loaf made with instant yeast. They were both delicious, but I preferred the loaf made with fresh yeast.
You can use fresh yeast in any recipe that calls for instant or active dry yeast. Swap in three times the amount of fresh yeast, by weight, as instant yeast or active dry yeast. I like to crumble the fresh yeast into the liquid ingredients and whisk to dissolve before adding them to the dry ingredients. I found that fresh yeast works best in enriched doughs, especially those with higher sugar content, I think that it keeps them a bit softer and you get a bit more volume. In his book Bread, Jeffrey Hamelman explains that dried yeasts, like instant or active dry, are more sensitive to doughs with higher sugar content. I mostly use fresh yeast when baking sweet loaves and Germanic breads, because that’s what the recipes call for.
Fresh yeast is available at many grocery stores in the refrigerated section, typically near the canned cinnamon roll dough or butter. Ask someone at the grocery store to help you find it. Fresh yeast is alive, so it has a very short shelf-life (usually two weeks or less). Only buy fresh yeast when you plan to use it in the next few days. Always check the expiration date, and do not use the yeast when it’s past that date. If you can’t find fresh yeast at your local grocer, then call around to local bakeries and see if they will sell you some. If you have any grocers that cater to Central or Eastern European cultures, they typically carry fresh yeast.
Natural leavening
You may know this type of leavener by another name: sourdough. I don’t say natural “yeast,” because the cultures in sourdough contain more than just yeast. Natural leavening captures the yeast (and other microbes) that live in the air by simply mixing water and flour. After several days of adding more flour and water, the natural yeast grows and becomes active enough to leaven a loaf of bread.
Sourdough starters are like a helpful pet. You have to feed and water them regularly to keep them active. However, if you only make sourdough occasionally (like me), you can keep your starter in the refrigerator and bring it out for a weekly feeding. When you’re ready to make a loaf of bread, start feeding your starter more frequently a couple days before you want to bake your loaf. Dough made with sourdough starter takes much longer to rise than commercial yeast, and is much more unpredictable. But sourdough gives you much more complex flavors, and sourdough bread lasts much longer after it’s baked. If I had the time (and patience) to make all of my breads using my sourdough starter, (named Pauline — like many bakers, I named my starter), I would. If you want to learn more and get started with sourdough, I suggest the Maurizio Leo’s book The Perfect Loaf. Or, bake and learn as you go.