# How do I substitute proofed dried active yeast for fresh yeast?

I have a recipe that calls for fresh yeast, but I want to substitute a particular weight of dried active yeast for the fresh yeast.

It seems from this question that I do not need to proof the dried active yeast and can simply weigh the amount of granules out of the dried yeast and just make the dough with that relying on the water content of the dough to work on the yeast.

What I am interested in though is if I decided to proof the yeast, how would I go about doing this to use in the recipe?

The bread recipe calls for a weight measure of yeast which is easy to achieve without activating the yeast. However activating the yeast calls for a specific weight of the yeast along with measurements of sugar and water. This would leave me with a liquid of a particular volume - this doesn't translate into a weight of dried active yeast too easy any more. Secondly, the bread recipe calls for water, yet adding the proofed yeast would change the ratios of this and I imagine alter the consistency of the dough.

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Good question - your title was backwards, though (see for example english.stackexchange.com/questions/23360/substitute-x-for-y). – Jefromi Feb 28 '13 at 1:41
@Jefromi Whoops! I'm sorry, I am a native English speaker but I suffer from dyslexia so easily get confused over that sort of thing. Thanks for the correction. :) – R4D4 Feb 28 '13 at 11:16

In both cases, you don't add the recipe's amount of water to the proofed yeast. If your recipe says e.g. 500 g flour, 300 g water and 10 g fresh yeast, you measure these 300 ml water, then pour some of the 300 ml over 10 g of pressed yeast to proof it, adding a teaspoon of sugar if you want it quicker. After that, you mix flour, proofed yeast and the remaining water together (for simplicity, I left out salt and possible other ingredients).

You do it exactly the same way with dry yeast, only you have to use the correct substitute ratio, which is 3:1. So you measure 300 ml of water and (1/3)*10 g = 3.3 g of dry yeast. Then you pour some of the 300 g of water over the dry yeast, and after it has bloomed, you mix flour, sponge and the remaining water. The bread hydration stays correct, and the fermentation time/amount is equivalent to the fresh yeast case.

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Very concise answer, thank you very much. :) – R4D4 Feb 26 '13 at 18:55

Proof the yeast in the water you mention in the last sentence.

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Thanks for your answer. :) – R4D4 Feb 26 '13 at 18:56

If you want to make sure it works properly, use instant and not active dry. Active dry will probably work, but you can't really rely on it. Instant yeast is a little closer to fresh yeast and keeps a lot more reliably. I have heard that on occasion a recipe pops up that requires dissolving the yeast in cold water; for that, you want cake yeast and nothing else, because dry yeasts can't handle the cold shock. Other than that, cake yeast is kind of a pain and not usually worth the effort.

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The OP is asking about this in the context of proofing, and the whole point of that is to verify that the yeast is going to work - so you can rely on it. – Jefromi Mar 1 '13 at 4:55