Checking active dry yeast means mixing it with suitable warm liquid and looking for activity before making the dough. This is different from proving dough, when an already mixed dough rises.
Before you start
- Read the yeast packet and your recipe. Use a small bowl and, where the packet specifies a temperature, a thermometer. Check the packet date and storage instructions.
Step by step
Prepare the liquid as directed
Use the amount and temperature specified by the yeast manufacturer’s activity test, or the measured liquid in a recipe that explicitly dissolves the yeast. Add sugar only in the amount directed. Warm does not mean hot: excessive heat can damage the yeast.
Stir in the yeast
Disperse the yeast in the liquid and leave it for the test time specified on the packet. Keep the bowl away from a cold draught. Avoid repeatedly stirring away the foam you are trying to observe.
Look for a foamy surface
A foamy cap and visible bubbling indicate activity. If the mixture remains flat after the specified time, check that the temperature and test quantities were correct. Retest with a fresh packet before committing the rest of the ingredients.
Image by JustRecipesAccount for the test ingredients
If the recipe uses the test mixture, include its liquid and sugar in the recipe totals. Do not add an extra bowl of test liquid to a dough that already contains its full liquid allowance.
An activity test is not always a required step
Many modern active dry and instant yeasts can be mixed directly with flour. Follow the packet and recipe: checking activity is useful when you doubt the yeast, but should not be presented as mandatory for every dough. A foamy test cannot guarantee a good rise if the finished dough is later mishandled.
