How to Prevent Sour Cream From Curdling in Soups and Sauces

Given the weather and general mood, I suspect that many of you have shifted into Soup Mode (except our editor-in-chief, Jordan Calhoun, a slightly misguided soul who maintains soup is “not a meal”). Soup Mode is good, as is its cousin, Creamy Sauce Mode, the mode where one feels inclined to drown proteins and vegetables in a luscious, often dairy-based sauce, and pile the whole mess on some noodles or rice. Both modes benefit from a little sour cream (or crème fraîche), but there is a right way to do it.

Adding a dollop of Daisy to your cream-of-whatever soup or beef stroganoff sauce is an easy way to give it a luscious body and creamy texture, but adding fridge-cold sour cream to a big, bubbling pot of hot soup or pan of sauce can cause the proteins to coagulate, curdling the cream and giving your dish an unappealing split appearance. But there is an easy way to avoid all of this. You just have to temper.

What is tempering?

Tempering is the act of slowly adding a hot ingredient to a cold one, to raise its temperature and make it more compatible with the overall dish. This is commonly done when adding eggs to custards and pastry creams (to prevent them from scrambling), but it’s just as valuable in comforting savoury dishes. (Do not confuse this with tempering chocolate, a method where the chocolate is heated and cooled to stabilise the fat to give it a shiny appearance and prevent blooming.)

How to temper

Grab a heat-safe bowl and add your cold ingredient to it. Slowly add a couple of small ladlefuls of the soup or sauce, one at a time, to the cold ingredient, whisking briskly to combine. Then add the tempered mixture back to the big pot of soup or sauce, whisking once more to create a smooth, creamy look and feel.