🍞 Yeast Conversion Calculator

Convert between active dry, instant and fresh (cake) yeast quantities using standard baking conversion ratios.

Amount

Unit

Yeast Type

Everything is converted through instant yeast

Whatever you type is turned into grams of instant yeast first, then the other two are rebuilt from it. Teaspoons of dry yeast are weighed at 3.1 g:

1 g instant = 1.25 g active dry = 3 g fresh (cake) yeast

instant grams = active grams / 1.25 = fresh grams / 3

The default, 2.25 tsp of active dry, is one standard sachet: 6.98 g. That comes back as 5.58 g of instant (1.80 tsp) or 16.74 g of fresh. So a recipe wanting one packet of active dry needs a scant 1 3/4 tsp of instant, or a 17 g lump of fresh - about two-fifths of a 42 g cube.

Why the three are not interchangeable gram for gram

Instant is the strongest by weight. Finer particles and gentler drying leave more live cells, so you need roughly 25% less of it than active dry. It also goes straight into the flour, where active dry is traditionally softened in warm liquid first.
Fresh yeast is about 70% water, which is the whole reason for the 3x figure - you are mostly buying moisture. It lasts around two weeks in the fridge against a year for a sealed dry sachet.
Enter fresh yeast in grams. The teaspoon setting uses the dry yeast density of 3.1 g/tsp for all three types, and crumbled fresh yeast is far lighter than that, so a teaspoon reading will be wrong.

Yeast quantity and rising time do not trade off proportionally. Halving the yeast lengthens the rise by well under double, and dough temperature matters more than dose - roughly a doubling of activity for every 10°C. Adding extra yeast to hurry things along mostly buys you a coarse crumb and a beery smell.

Frequently asked questions

How much instant yeast do I use instead of active dry?

About 25% less. A 7 g sachet of active dry becomes 5.6 g of instant, which is 1.8 tsp rather than 2.25. Stir it into the flour and skip the proofing step.

How much fresh yeast equals a packet of dry yeast?

Roughly 17 g of fresh for one 7 g packet of active dry, or 3 g of fresh for every gram of instant. Crumble it into the liquid rather than adding it dry.

Can I use less yeast and let the dough rise longer?

Yes, and the bread is usually better for it. A quarter of the yeast with an overnight rise in the fridge gives the enzymes time to develop flavour the fast version never gets. Judge it by the dough doubling, not by the clock.