Most of us who dabble at making breads once in awhile usually buy yeast like this:
This is the most expensive way to buy yeast, but if you don't bake with yeast often, it's probably the simplest and easiest way to go. Yeasts do go bad. Or better put, it will eventually die. So, if you don't make breads often, don't buy much.
You can still buy it in bulk in some stores though. Our local Whole Foods used to carry baker's active dry yeast in bulk bins. That way I could get as little or as much as I wanted for about 75% less. However, they no longer carry it. A local organic store here carries yeast in bulk for much cheaper too (as I hear some big box clubs do to), but in a big vacuum sealed bags like this:
But, notice all the different names: Active dry yeast. Traditional active dry yeast. Rapid Rise yeast and then fresh active yeast (seen below):
I picked all Fleischmann's for photos because I wanted to show that it's the same company that is using all these different names too. Fleischmann's is not the only company making/packaging yeasts. You'll also see Red Star too and perhaps a couple others.
But how do they differ?
Well, Fresh Active yeast/compressed yeast/cake yeast is just that - fresh and active. They have a very short shelf life and need to be kept refrigerated. Some older recipes will specify this type of yeast, but you can use other yeast in it's place (see conversion info below).
Active dry yeast many times needs to be proofed (as their granules are bigger and don't dissolve as well into the dough without proofing) and it most often requires two risings of the dough.
Instant/Rapid/Bread Machine yeast are all the same yeasts and they do not need to be proofed, only require one rising and are well, faster!
Here is a great description from this site that talks all about yeasts and how to use them and interchange them: http://www.breadworld.com/faq.aspx
Frequently Asked Questions
How much dry yeast is in 1/4 ounce envelope?
About 2 1/4 teaspoons.
How should I store yeast?
Store unopened yeast in a cool, dry place, such as a pantry (or refrigerator). Exposure to oxygen, heat or humidity decreases the activity of the yeast. After opening, store in an airtight container in the back of the refrigerator, away from drafts. Use within 3 to 4 months; freezing not recommended.
Can I use expired yeast in my recipe?
For best results, buy and use yeast before the expiration date. Yeast loses its potency as it ages, resulting in longer rising times. Proof yeast to determine whether it is still active.
How do I proof yeast to test for activity?
To proof yeast, add 1 teaspoon sugar to 1/4 cup warm water (100° to 110°F). Stir in 1 envelope yeast (2 1/4 teaspoons); let stand 10 minutes. If the yeast foams to the 1/2 cup mark, it is active and you may use it in your recipe. RapidRise™ yeast loses its fast rising capabilities if dissolved in liquid, and will require two complete rises.
Can RapidRise™ and Bread Machine Yeast be used in Active Dry recipes?
Yes. Simply follow the One-Rise Method detailed on every package. For best results, add undissolved RapidRise or Bread Machine Yeast to dry ingredients first. Add liquids and fat heated to 120°to 130°F. To use the traditional Two-Rise Method, add sugar to water before stirring in Yeast
Can Active Dry Yeast be used in RapidRise recipes?
Yes, but with limitations. The Active Dry has larger granules and it is necessary to dissolve completely for the yeast to work. Therefore, Active Dry works best if dissolved in warm water (100° to 110°F).
What is the difference between Instant Yeast, Bread Machine Yeast and RapidRise Yeast?
Mainly names, but these are all the same yeast! Use interchangeably.
What is the difference between fast-rising yeast (RapidRise/Bread Machine Yeast) and Active Dry Yeast?
RapidRise and Bread Machine Yeast are different strains than Active Dry Yeast. RapidRise and Bread Machine Yeast are grown with a higher level of nutrients and are dried to lower moisture content. The particle size of RapidRise and Bread Machine Yeast are finely granulated to allow complete hydration of the yeast cells during the mixing process. The Active Dry Yeast larger particle size should be dissolved in water to achieve complete hydration prior to adding to the mixer. In addition, RapidRise and Bread Machine Yeast contain ascorbic acid resulting in increased loaf volumes.
How do I use Fresh Active Yeast?
Fresh Active Yeast is the product that Fleischmann's has been manufacturing for over 130 years. It is also traditionally known as compressed or cake yeast. It has not undergone the drying process, so it does not need to be dissolved before use: soften the cake in warm water first OR simply crumble the yeast into dry ingredients (if directed by recipe). Fresh yeast requires two rises. Yeast is available in two different sizes: 0.6 ounces and 2 ounce household cakes
How do I substitute dry yeast for Fresh Active Yeast?
One .6 ounce cake is equivalent to 1 envelope of dry yeast. One 2-ounce cake is equivalent to three envelopes of dry yeast. Follow the directions on the package recommended for the type of yeast you substitute.
Can Active Dry Yeast be used in bread machines?
Bread Machine Yeast is specially formulated for bread machines and recommended by most bread machine manufactures. It is finely granulated to hydrate easily when combined with the flour. Ascorbic acid (vitamin C) is added to promote good loaf volume and structure. Active Dry Yeast may be used but may not yield optimal results.
What this doesn't go into detail about is how these differing types of baker's yeast affect the flavor of the bread. Maybe most people don't notice the difference, but if you experiment a bit, you learn that doughs that rise for longer, ferment a bit, have a better flavor. Well, if we really, really think about it, what's most people favorite breads? Sourdoughs and other artisan breads and that's because the yeasts have had time to change the dough to help it develop more flavor.
If you really get into baking breads and you will see all sorts of new terms - preferments, poolish, bigas, etc. All of them are basically yeasted starters that add more life and flavor to your bread. This extra long preparation of breads is what makes artisan breads so wonderfully tasty and pricey. They take longer because of letting the yeast develop longer. Want to know more? Check out King Arthur's great description of preferments: http://www.kingarthurflour.com/professional/preferments.html.
What does this mean for you and me? People who want to get into baking to make it cheaper or to make it healthier or both? Well, for me, an amateur baker, it means that I don't buy instant, rapid rise or bread machine yeast. It doesn't develop enough flavor in the dough as it just rises too fast to give the dough some definition. I use active dry yeast, or traditional yeast. I also stay away from the cake/compressed yeast just because it's expensive and it is short-lived. Since I bake a lot, I buy the vacuum sealed 1 lb. bag of active dry yeast. I store it in an air tight container in my pantry. I don't refrigerate as I will go through it fast enough.
If it's bulk, how can you be sure which is which if it's not labeled well or it's a newer label that you haven't seen before? Well, they look different too. Active dry yeast are tiny beads. They look like this:
Instant or bread machine yeast will look like this:
So basically, if you see they are almost a powder, or very small pellets, it's probably a form of instant. If they are bigger pellets or are round, it's active dry yeast.
As far as preferments go for developing flavor even further I do sometimes make preferments, but so far I haven't dabbled beyond any preferments that takes longer than 2-3 hours. Maybe someday I'll get really into bread baking, but for now, this is fine and my family is satisfied.
Last thing I will mention is absolutely do not buy brewer's yeast or nutritional yeast for baking. These are nutritional supplements. Brewer's Yeast is used for medicinal purposes and for forms of Vitamin B. Nutritional yeast is also for complex B Vitamins as well as being a complete protein to be used in vegetarian and vegan diets. Neither of these yeasts are active, so therefore your bread would never rise/grow if you tried to use these instead of baker's yeast.
Never knew there was so much to it, did ya?