Several sources (e.g., The Bread Baker's Apprentice, The Fresh Loaf's Yeast FAQ, and even On Food and Cooking) tell me that active dry yeast must be reactivated by proofing in warm water, or the bread won't rise adequately.

My bread machine manual says to keep it dry, so I have. I've kneaded it into breads I've made by hand, once again dry. I've mixed it with the dry ingredients in a stand mixer, before adding water. None of these fail to rise adequately, or noticeably less than when I proof it. (I'm using Red Star Active Dry Yeast)

I'm wondering, am I missing something? Why does something that according to almost anywhere I look is not supposed to work seem to work just fine?

The only clue I've got is that On Food and Cooking warns that "at cooler soaking temperatures, the yeast cells recover poorly and release substances that interfere with gluten formation (glutathione)."

edit: To clarify: yes, it's active dry yeast; "Red Star Active Dry Yeast" in particular. Yes, the bread machine manual says active dry yeast, not instant, and has different instructions for rapid rise.


5 Answers 5


No, it isn't actually necessary. The yeast activates just fine with the moisture in the bread. I've been using Active Dry Yeast for years and hardly ever bother with proofing it.

Proofing shows that the yeast is actually alive. If you have any doubt about it, proof it as the first thing that you do, before mixing up the other ingredients (and especially before putting liquid in). If it fails then you didn't waste materials.

  • 3
    When we found a jar of active dry yeast in the freezer that was three years old, proofing was vital to discover that the yeast was dead. However, for recently bought yeast, you don't actually need to proof it.
    – Martha F.
    Commented Feb 18, 2011 at 17:50

Your bread machine manual is probably telling you to use instant yeast and not active dry yeast if you are not to hydrate it first.

Instant yeast (which is my favorite) can be added directly whereas active dry yeast has to be rehydrated first -preferably with warm water.

  • No, it clearly says "active dry". It has different instructions (and settings on the machine) for rapid rise. And I've definitely been using active dry, and it works.
    – derobert
    Commented Feb 18, 2011 at 17:16

Yes,active dry yeast need to be reactivated.Instant dry yeast don't need it. Active dry yeast must be reactivated by proofing in warm water, or the bread won't rise adequately.


Late to the party but, YOU DO NOT need to “prove” (as it was called way back when) yeast BEFORE using it UNLESS you are unsure of it. If it is old and you can’t remember how long you have had it then you need “PROOF” that it will work. You don’t want to waste all of your ingredients by using something that is dead and won’t cause your dough to rise so, if you’re using a typical 1/4-ounce packet of yeast, just follow the directions on the back: dissolve the contents of the packet in 1/4 cup warm water with 1 teaspoon sugar. After 10 minutes, the mixture should be bubbly. Once you’ve “proved” the yeast is still alive, go ahead and add it to your recipe – reducing the water in the recipe by 1/4 cup. 👨🏼‍🍳Source: the chef who taught me in culinary school.

  • 2
    Erm, putting the yeast in some water with a bit of sugar to activate it before adding to the rest of the ingredients is typically considered “proofing”?
    – Stephie
    Commented Nov 11, 2018 at 12:12

I have been successfully making 1-2 loaves a week using a low-end ToastMaster bread machine for 11 years.

Their manual says:


"For all programs except FAST BAKE™ we used RED STAR® Active Dry Yeast when we developed the bread recipes. However, RED STAR® QUICK•RISETM Yeast may also be used. We found that we did not have to vary the amount used when we substituted one for the other. When using bread machine yeast, follow the package instructions."


I use Red Star Active Dry Yeast that I keep in a jar in my fridge. I do not "reactivate" it and get nice tall and tasty loaves.

I just replenished that jar with yeast from a 3 year old package of Red Star Active Dry Yeast that has been double sealed in plastic stored in my freezer, and it came out fine.

proofed 3 year old frozen Active Dry Yeast

100% whole wheat w/ raisins

Hope this helps.

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