There are a few simple things you can do to ensure that you never have a stuck fermentation:
First, just make sure your fermentation area is between 65 and 75 °F.
Make sure that your equipment is properly cleaned and sanitized.
Always use fresh yeast, and make sure you are using the yeast called for in the recipe.
Don’t use any old packet you have laying around. Hydrating your yeast before pitching also helps, but make sure that you pitch the yeast within 20 minutes of hydration.
Adding yeast nutrient before pitching the yeast gives the yeast nourishment so that it will stay healthy throughout the fermentation process. Use 1 teaspoon per gallon.
Lastly, aerate the must by vigorously stirring it just prior to pitching the yeast. Yeast needs oxygen to begin fermentation.
