Yeast Conversion: Instant, Active Dry and Fresh Yeast

Use 1 g of instant yeast for every 1.25 g of active dry yeast or 3 g of fresh (cake) yeast. One standard packet holds 7 g, about 2¼ teaspoons, of either instant or active dry yeast.

The three main types

Fresh yeast is mostly water, which is why you need about three times as much. Active dry yeast has larger granules with a layer of dormant cells on the outside, so it is a little weaker gram for gram than instant.

Conversion chart by weight

Fresh yeast to dry

Spoons to grams

Instant and active dry yeast weigh about the same by volume.

For small amounts in long, slow doughs, a scale that reads to 0.1 g helps a lot.

A simpler rule many bakers use

Modern active dry yeast is much more vigorous than it used to be, and many bakers simply swap it 1:1 with instant. The dough may rise a little more slowly with active dry, which is rarely a problem. The 1.25 ratio matters most in lean breads with long rises, where yeast amount controls timing.

Packets around the world

A packet of dry yeast typically raises about 500 g (4 cups) of flour in an ordinary sandwich bread.

Yeast as a percentage of flour

Bakers often express yeast as a baker's percentage of flour weight.

Sugar, butter and eggs slow yeast down, which is why enriched doughs need more of it.

Temperatures that matter

Swapping yeast for sourdough starter

There's no exact conversion, but a workable start: replace a 7 g packet in a 500 g flour recipe with about 100–150 g of active, bubbly sourdough starter (100% hydration). Remove half the starter's weight from the recipe's flour and half from its water, and expect the rise to take 4–8 hours instead of 1–2.