We’ve all been there. You’re knee-deep into a recipe for homemade biscuits, baked potatoes, or beef pierogis only to realize you forgot to pick up a necessary ingredient: sour cream. Don’t panic! Making sour cream from scratch only requires three ingredients: milk, distilled white vinegar, and heavy cream. Or, if you have buttermilk on hand, you can skip the milk and vinegar and use that instead. Once you taste homemade sour cream in coffee cake or French onion dip, we swear you’ll never go back.