With all of the varieties of yeast out there (let alone brand names), how do you know which yeast to use?

Traditional active dry yeast and fast-rising yeast

Active dry yeast (ADY), the stuff your mom may have used, is widely available everywhere. You'll find it in your supermarket's cold case in 1/4-ounce packets, three packets to a strip; it's also available in bulk, in 4-ounce jars. ADY is the tortoise in the tortoise/hare race: while slow to get going, it provides hours of steady growth.

Then there's fast-rising yeast (a.k.a. highly active yeast) – the hare in the race. Fleischmann's RapidRise® is the most popular brand. These yeasts purport to work 50% faster than ADY.

Versatile SAF instant yeast

Here's our favorite yeast: SAF instant yeast, a King Arthur Flour test kitchen staple for decades. SAF gets going much more quickly than ADY, and has just as much staying power.

SAF instant yeast is appropriate for all dough, from your standard sandwich bread with its minimal rising, to multi-day refrigerated no-knead dough, to frozen-dough dinner rolls.

Note: The nomenclature for yeast can be very confusing: bread machine yeast, fast-rising yeast, instant, active dry, instant dry ... To avoid confusion on our recipe site, we simply call for instant yeast. The yeast we use in our King Arthur test kitchen is SAF instant yeast (Red or Gold); so when you see a recipe on this site calling for instant yeast, we're referring to SAF instant yeast.

Why choose ADY or fast-rising yeast instead of instant?

Instant yeast certainly looks like the way to go. Still, there are times when bakers might choose active dry yeast, or one of the fast-rising yeasts. Why?

Comfort and tradition. Some bakers simply love to use what they've always used, or what their mom or grandma used. Carrying on family baking traditions is important, and certainly a valid reason for sticking with your tried-and-true active dry yeast.

Flavor. Many bakers report a difference in flavor between active dry and instant or fast-rising yeast, with ADY lending bread milder, less aggressively "yeasty" taste.

Fear and confusion. "My recipe calls for active dry yeast, so I have to use active dry yeast."

Not true! It's easy to use instant yeast in recipes calling for ADY or fast-rising yeast – no fancy conversions needed. Simply use the same amount of instant yeast in your recipe as ADY or fast-rising. Add it right along with your other dry ingredients; there's no need to dissolve instant yeast in water first.

Let's put all three yeasts to the test.

How do these three most common yeasts – active dry, fast-rising, and instant – perform against one another?

Active dry yeast takes longer to work.

Here we have (l to r) Red Star ADY, Red Star Quick-Rise, and SAF Red instant yeast. I've just kneaded the dough, and it's going through its first rise in mini loaf pans (top).

The Quick-Rise and SAF instant yeasts are about equal in volume after an hour; the ADY is lagging behind (bottom).

Now let's shape and bake these breads.

Here they are shaped and in the pan (top); and 1 hour later, risen.

The ADY is still behind Quick-Rise and SAF instant. SAF (right) has pulled ahead of Quick-Rise just a tad, though you can't see it from this angle. In fact, the SAF loaf has crowned about 1/4" over the rim of its pan, so I put it into the oven to bake. Fifteen minutes later, the Quick-Rise loaf is also ready, and goes into the oven.

A full hour after the first loaf went in, the ADY loaf still isn't fully risen. The point's been made by now; ADY is slower than both Quick-Rise and SAF instant. So I go ahead and bake it.

The finished loaves

Here's a cross-section of the results. That's ADY on the left; Quick-Rise in the center, and SAF Red on the right.

The SAF Red and Quick-Rise loaves bake to virtually the same height, but the SAF loaf rises a bit more quickly in the pan than the Quick-Rise.

The ADY loaf is shorter – though, given enough time, it would have risen fully and no doubt produced as tall a loaf as its Quick-Rise and instant competitors.

Flavor-wise, both the Quick-Rise and SAF instant yeast loaves have a distinctly yeasty flavor and aroma, while the ADY loaf's flavor is more neutral.

The overall winner? SAF instant, by a crumb.

By virtue of its fast, strong rise; and its versatility (standard, no-knead, and refrigerated/frozen doughs), we choose SAF instant.

OK, now that we've established SAF instant yeast is the ideal all-around yeast, we have another potential decision to make:

Which SAF yeast to use, Red or Gold?

SAF Red is your best choice for all-around baking, from sandwich loaves to crusty no-knead bread to freeze-and-bake dinner rolls.

SAF Gold is formulated for one specific type of dough: sweet dough. Think Portuguese Sweet Bread, Hawaiian Buns, Panettone, Raisin Challah, and the like.

What about cinnamon rolls or sticky buns, you ask? Well, they're sweet – but mainly from their topping/filling. The dough for these sweet rolls is often only lightly sweetened, if at all; so they don't need SAF Gold.

Here's a rule of thumb: if the weight of the sugar in your recipe is equal to or greater than 10% of the weight of the flour, SAF Gold will hasten the dough's rise.

Roughly translated to volume, any recipe calling for over 1 tablespoon sugar per cup of flour will benefit from SAF Gold.

But can't you just use SAF Red, and let everything rise longer?

Yes – but there's a tradeoff. Most sweet doughs also include eggs, milk, and/or butter. Letting these elements sit at warm room temperature for hours at a time, as the dough rises, can cause them to take on a slightly tangy, fermented flavor; and this flavor can clash with the appealing sweetness of your finished loaf. SAF Gold, with its shorter rising time, prevents this flavor deterioration.

Let's see what happens when we test Red against Gold in our Hawaiian Buns. With the buns' sugar/flour ratio climbing above 22%, they're one sweet candidate for this test!

Here are the two doughs just after mixing (top), and 90 minutes later (bottom). That's SAF Gold on the left, SAF Red on the right.

I shape the dough into buns, and let them rise for an hour (bottom).

The SAF Gold buns (left) have risen slightly more than the Red buns; see how the Gold buns are filling more of the pan?

And here they are, baked and ready to enjoy.

SAF Gold wins the sweet dough test.

That's Gold on the left, Red on the right. In sweeter recipes, Gold produces a higher-rising bun.

So we've gotten to the end of our tests, and I'm happy to say SAF instant yeast has validated my long-time faith. For the full range of all my yeast baking, SAF is the choice.

Still, there's one more reason to choose SAF instant yeast:

The price is right.

Sold in its typical three-packet, 3/4-ounce strip, active dry yeast or fast-rising yeast at the grocery store costs around $40 a pound.

A pound of SAF Red instant yeast – the equivalent of 64 (1/4-ounce) packets – costs $5.95.

Are you worried about using up a pound of yeast? Stored in your freezer, it'll stay good for at least a year, and probably longer. In fact, though the manufacturer would certainly never recommend it, I've used 6-year-old instant yeast (stored in the freezer), and still achieved good results.

SAF gives you the most bang for your buck. Its value, combined with quality, seals the deal for me.

Which yeast to choose – the bottom line:

P.S. For those of you who go WAY back, fresh yeast (cake yeast) was the staple of every bread baker's kitchen. These days, though, the familiar foil-wrapped cubes are available only in scattered grocery stores. So for the sake of simplicity, I didn't include fresh yeast in these tests.

Looking for more information on successful yeast-bread baking? See our 5 Quick Tips for High-Rising Yeast Loaves.