Easiest Way to Improve the Flavor of Soups and Stews

By the editors of Cook's Illustrated

Why does a soup taste better the day after it's made? And other delicious effects of chemical reactions over time.

Soups and stews are ideal for cold winter nights. And good news for cooks who enjoy make-ahead meals: Cooking batches ahead of time and reheating them when you want them is not only a great way to get dinner on the table quickly, but the meal will taste better than a freshly made pot, too.

Why Does Flavor Improve Overnight?

To get to the bottom of why the flavor of soups and stews improve when made in advance, we had a conversation with our science editor, Guy Crosby. He explained that even after cooking ceases, many chemical reactions continue to take place in foods. In the case of a soup or stew containing milk or cream, the lactose breaks down into sweeter-tasting glucose. Similarly, the carbohydrates in onions develop into sugars such as fructose and glucose. Proteins in meat turn into individual amino acids that act as flavor enhancers. Finally, starches in potatoes and flour break down into flavorful compounds.

To verify this, we made batches of Best French Onion Soup, Simple Beef Chili, and Creamless Creamy Tomato Soup and refrigerated them. Two days later, fresh batches of each recipe were served hot alongside the reheated soups and stews. Tasters unanimously preferred the onion, tomato, and black bean soups that had been held for two days, calling them “sweeter,” “more robust-tasting,” and “well rounded.” When it came to the chili, most tasters made the same comments, but some preferred the fresh sample—as it sat, the chile flavors became sweeter and less sharp. If you like vibrant chile flavor, it’s best to serve chili the same day you make it.