Simple syrup is usually good for about 1 month in the fridge if it’s a standard 1:1 sugar-to-water mix, and up to about 6 months if it’s a richer 2:1 syrup. Flavored versions often spoil sooner, especially if they include fresh fruit or juice.

Quick scoop

  • Standard simple syrup: about 1 month refrigerated.
  • Rich simple syrup (2:1): up to 6 months refrigerated.
  • Flavored syrup with fresh fruit or puree: often 2–3 weeks or less.
  • Store-bought opened syrup: commonly 1 to 6 months , depending on the product and storage.

Signs it’s gone bad

Toss it if you notice:

  • Mold.
  • A sour or off smell.
  • Cloudiness that wasn’t there before.
  • Crystallization plus an odd smell or taste.

Storage tip

Keep it in a clean, airtight container in the fridge for the best shelf life.

If you want, I can also give you a “how to tell if simple syrup is still safe” checklist.