For a long time, most ingredients fell into one of two personal categories: The stuff I always had (flour, eggs, butter, A1 Sauce—a personal obsession and a story for another time), and the stuff I NEVER had. Ever. Example: If a recipe called for buttermilk, I'd lose my mind. I wouldn't think to buy it at the supermarket each week. And because I had to frantically search for a solution so many times, I now know it by heart: I do the same measure of whole milk with roughly a cap-full of white vinegar.

I've started a list of things I make sure to buy or replenish—even if they seem extraneous. It really has saved me. Add them to your shopping list, and I promise they will not go to waste—because I'll also tell you how not to waste them.

Buttermilk: I use this as the top example because I went from never having it to now not being able to live without it. Chocolate cupcakes, Texas sheet cake, waffles—just a few of the things made better by its existence. Frankly, I'll often use it when recipes call for plain milk because it adds a richness that milk alone doesn't. The good news: This stuff takes forever to go bad (so you're not buying it one week and tossing what's left the next). The better news: When it is about to expire, my lucky family gets pancakes.

Lemons: At random moments throughout the year, I get into a lemon zone. I make lemon bars, lemon meringue pie, lemon-garlic shrimp—often times in rapid succession. But fresh lemon juice also pops up in recipes when I least expect it: as a drop of acidity in a soup, a flavor addition to a marinade. If I'm not in the zone, I'm screwed. Now, I keep them on hand all year round, and put them to good use if too much time passes. I squeeze some into a pot of cooking rice and to keep the rice from sticking together; I'll add the same amount to the water when I'm blanching vegetables to keep their colors bright.

Sour Cream: You either love this stuff or hate it. I'm the former: A baked potato with sour cream and chives is one of my all-time favorite foods. Sour cream often gets a bad rep because it can be so high in fat—but you don't need a lot of it to make it work hard in your recipes. I use it in zucchini bread or pound cake batter to make the final result more decadent, or mix into a creamy dressing to give it more body.

Red wine vinegar: There's a reason why every dish you put balsamic vinegar in becomes "balsamic whatever:" It overpowers everything it touches. I've only recently begun to appreciate its milder cousin, and I now make sure I'm never without it. It adds acidity and depth of flavor in a subtle way. (My dad loves this stuff so much that he often orders a salad with extra on the side.) Just a couple of my favorite uses: A drop in a slow-cooked beef stew rounds out the flavors; a little bit in chicken or tuna salad cuts through all that creaminess.

What surprising ingredient can you not live without? Leave me a comment, and let me know how you use it.