Why won't my yeast activate when making cinnamon rolls?

"Why won't my yeast activate when making cinnamon rolls?"

I get asked this a lot here in Canada, especially once the cinnamon roll baking starts and a batch just sits there doing nothing. Before you blame the recipe, suspect the yeast itself.

Even newer yeast can already be dead. The milk in the dough makes it hard to tell, so test the yeast on its own first.

Stir it into plain warm water with a little sugar, separate from the milk. Then wait ten minutes and watch the surface.

If there is no foam after ten minutes, the yeast is done. No foam means replace it with a fresh pack instead of wasting the whole batch of dough finding out.

Asked on r/AskBaking

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