Can I use too much yeast?

The answer

Yes, too much yeast gives a harsh, yeasty taste and a dough that rises quickly and may then collapse. Using the amount in your recipe, or the packaging guidance, matters more than adding extra; a 7 g packet holds about 2¼ teaspoons. A smaller amount with a longer, cooler rise usually gives better flavor and a more stable dough. Too little yeast is the opposite problem, producing a slow, heavy dough. When in doubt, use slightly less and allow more time.