Active dry yeast is a dormant form of yeast and needs to be rehydrated or proofed prior to using it in a recipe. This means that the yeast needs to be dissolved in warm water (a bit of sugar helps the yeast to activate more quickly since sugar acts as a food for the yeast) and left for a few minutes to activate before using in the recipe.

Instant yeast is different than active dry yeast in that it does not need to be rehydrated or proofed prior to using in a recipe. The granules of instant yeast are smaller than active dry yeast and you can add the yeast directly in with all the other dough ingredients without letting it activate in warm water first.

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