The recipe asks for a packet of active dry yeast. The shop only had instant yeast, or a friend gave you a block of fresh yeast. Can you use it, and how much? Bread is unforgiving about yeast, and too little means a dense loaf and too much gives a loaf that tastes of beer.
Active dry, instant and fresh yeast are the same organism in different forms, and they are not used in equal amounts. This yeast converter swaps between them, and between grams, teaspoons and packets.
How to use the Yeast Converter#
- Enter the amount. Type the amount of yeast in the recipe.
- Choose the unit. Packets, teaspoons, grams or ounces.
- Say what the recipe calls for. Pick active dry, instant or fresh.
- Say what you have. Pick the type of yeast you want to use.
- Read the result. The amount is shown in grams and teaspoons, with the third type below it.
The three types of yeast#
Active dry yeast is sold as small granules with a dried outer coating, and it is usually dissolved in warm water before use. Instant yeast, also called rapid rise or bread machine yeast, has finer granules and no coating, so it can go straight into the flour. Fresh yeast, also called cake or compressed yeast, is a moist block that is crumbled into the dough or dissolved in liquid, and it has the shortest shelf life, a couple of weeks in the fridge.
Conversion ratios#
Instant yeast is stronger than active dry yeast because more of its cells are alive, so you use about three quarters as much. Fresh yeast contains water, so you need more of it by weight. A standard packet of dry yeast, about 7 grams, is equal to a 0.6 ounce cake of fresh yeast, which is about 17 grams. The calculator therefore uses 2.4 times the weight for fresh yeast. Some sources use a ratio of 2 to 3, so treat it as a close starting point.
| Type | Equal to one 7 g packet of active dry | Teaspoons |
|---|---|---|
| Active dry yeast | 7 g | 2 1/4 tsp |
| Instant yeast | 5.3 g | 1 3/4 tsp |
| Fresh yeast | 17 g (0.6 oz) | n/a |
Grams, teaspoons and packets#
A standard US packet of yeast holds 1/4 ounce, which is about 7 grams or 2 1/4 teaspoons. That works out to about 3.1 grams per teaspoon of dry yeast. Packets from some other countries are different, so check the label. If a recipe calls for one packet, use a scale and weigh 7 grams, which is more reliable than a teaspoon. A loose spoonful of granules can vary by a fifth.
Using the swap in a recipe#
Swapping yeast types does not change the recipe much. If you replace active dry yeast with instant, skip the step of dissolving it in water, mix it into the dry ingredients and use the amount the calculator gives. Instant yeast may rise a little faster, so watch the dough and not the clock. If you use fresh yeast, crumble it into warm liquid and stir until it dissolves. Cold or old fresh yeast loses strength, so use it within the date on the pack.
Check that your yeast is alive#
If you are not sure the yeast is good, test it. Mix a teaspoon of yeast and a pinch of sugar into half a cup of warm water, about 105 to 110 degrees Fahrenheit, which is warm but not hot. After ten minutes it should be foamy. If nothing happens, the yeast is dead or the water was too hot, and you should start again. Water much hotter than about 130 degrees Fahrenheit can kill yeast.
Storing yeast#
Unopened packets of dry yeast keep well in a cool, dry cupboard until the date on the pack. Once opened, the yeast loses strength faster, so keep it in a sealed container in the fridge, or in the freezer if you bake rarely. Cold yeast should come to room temperature before you use it, or you can mix it into the flour without dissolving it. Fresh yeast has a much shorter life, usually a couple of weeks in the fridge, and it can be frozen in small pieces. Fresh yeast that has turned dark, dry or smelly should be thrown away. If you suspect any yeast is old, use the foam test described above before you commit a whole batch of dough.
Frequently asked questions#
About 1 3/4 teaspoons, or about 5 grams, which is three quarters of a packet.
About 17 grams, or 0.6 ounces, which is one small cake.
About 2 1/4 teaspoons, which is 7 grams or 1/4 ounce.
Yes. Use about three quarters as much and mix it straight into the flour.
Yes. Use a third more, and dissolve it in warm water first.
Mix it with warm water and a pinch of sugar. It should foam within ten minutes.
Sources and further reading#
- Red Star Yeast. Packet size and cake yeast equivalence from a yeast maker.
- Fleischmann’s Yeast. Product information on active dry and instant yeast.
- Wikipedia: Baker’s yeast. Forms of baker’s yeast and their relative strength.
- King Arthur Baking: Ingredient Weight Chart. Weights per cup for flour, sugar, butter, honey and more.