Yeast Converter

Three kinds of yeast, one job

Fresh yeast, active dry yeast and instant yeast are the same organism prepared in different ways, so they can replace one another if you adjust the amount. Fresh yeast is soft and moist, active dry is dried into larger granules, and instant is dried into fine granules that dissolve quickly. Because they contain different amounts of water and live cells, a gram of one is not a gram of another.

This converter takes whatever you have in the cupboard, whether it is weighed, spooned, in a packet or in a cube, and shows the equivalent of all three types. Use it when the recipe names a yeast you don’t have, or when an older recipe lists fresh yeast and your shop only sells dried.

Why the amounts differ

Fresh yeast is roughly two thirds water, so much of its weight is not yeast at all. Drying concentrates the cells. Active dry yeast has larger granules with a layer of dormant cells on the outside, which is why it is traditionally dissolved in warm water first. Instant yeast is dried more gently and ground finer, so more of it is active and it can go straight into the flour.

Those differences give the standard conversion the calculator uses: 1 part fresh yeast equals 0.4 parts active dry or one third of a part instant, by weight. Brands vary a little, so treat the result as a close starting point rather than an exact equivalence.

How to convert

1. Under Yeast you have, choose the Type: Instant (rapid rise), Active dry, or Fresh (cake, compressed).
2. Pick how it is Measured in: Weight, Teaspoons, Packets (7 g, 2¼ tsp) or Fresh yeast cubes (42 g).
3. Enter the Amount.

The top results show the equivalent weight of Fresh yeast, Active dry and Instant. Below, Spoons and packs gives teaspoons for the dry types, how many 7 g packets that is, and the equivalent in fresh yeast cubes. The Metric and Imperial switch changes the weights between grams and ounces.

Worked example: an old recipe calls for 25 g of fresh yeast

You only have instant yeast. Choose Fresh (cake, compressed), measured by Weight, and enter 25 g. The converter shows:

• Fresh yeast: 25 g
• Active dry: 10 g
• Instant: 8.33 g
• Active dry, teaspoons: 3¼ tsp
• Instant, teaspoons: 2⅝ tsp
• Active dry, 7 g packets: 1.43
• Instant, 7 g packets: 1.19
• Fresh yeast cubes (42 g): 0.6

So you would use 8.33 g of instant yeast, or just over one packet. Teaspoons are rounded to the nearest eighth, based on about 3.1 g of dry yeast per teaspoon.

Going the other way, one packet of active dry yeast (choose Active dry, Packets, amount 1) works out to 17.5 g of fresh yeast or 5.83 g of instant, which is 1⅞ tsp. A single level teaspoon of instant yeast is 3.11 g, the same as 9.33 g of fresh.

Tips and mistakes to avoid

• Weigh small amounts when you can. A teaspoon of yeast can vary by a gram depending on how it is scooped, which is a big difference in a slow dough.
• Keep active dry yeast happy. If you use it in place of instant, dissolving it in some of the recipe’s lukewarm water for a few minutes helps it get going.
• Hot water kills yeast. Water that feels hot to the touch, well above body temperature, can damage it. The dough water temperature calculator helps you choose a safe, useful temperature.
• Fresh yeast does not keep. It lasts a couple of weeks in the fridge. If it is dry, crumbly and dark, replace it.
• Adjust timing, not just amount. Using less yeast than a recipe says is fine if you allow a longer rise.

In pizza dough, where yeast is usually given as a percentage of flour, the pizza dough calculator converts the percentage automatically when you switch yeast types.

Yeast questions

Can I swap instant and active dry yeast one for one?

Many bakers do, and in a long rise the difference is small. For closer results, use about 20% more active dry than instant, which is what the 0.4 and one third ratios work out to.

Why can’t I enter fresh yeast in teaspoons?

Fresh yeast is soft and crumbly, so a teaspoon of it is not a reliable measure. The converter accepts it by weight or in standard 42 g cubes instead.

Is a packet always 7 g?

In the US a standard packet holds 7 g, about 2¼ teaspoons. Sachets elsewhere can differ, so check the label and enter the weight if it is not 7 g.

Can I convert yeast to sourdough starter?

Not with a simple ratio. Sourdough brings acidity, flavour and a much slower rise, so the whole recipe and its timing change. The sourdough recipe builder is a better place to start a sourdough version.

Does yeast go off?

Dried yeast keeps well sealed, especially in the fridge or freezer, but it slowly loses strength. If a dough is rising unusually slowly, test the yeast in warm water with a pinch of sugar; it should foam within about 10 minutes.