Sour Cream Sauce

This sour cream sauce is about as fast as sauce-making gets. A cornstarch slurry mixed with dill, salt, and sour cream heats through in about a minute, thickening into a smooth, creamy sauce that works on everything from baked fish to steamed vegetables to boiled potatoes.

The cornstarch-water slurry gets mixed first, completely smooth and lump-free, before the sour cream goes in. This order matters. Adding cornstarch directly to sour cream creates stubborn clumps that won’t dissolve no matter how much you stir. Dissolving it in water first ensures a perfectly smooth sauce every time.

Keeping the heat at medium-high and cooking for just one minute is enough to activate the cornstarch and warm the sauce through. Going longer or higher risks breaking the sour cream, which turns it grainy and thin instead of thick and glossy. Constant stirring keeps everything in suspension and prevents the bottom from scorching.

Kitchen Tips

• Don’t let it boil. Sour cream separates at high temperatures. A vigorous simmer is the hottest you should go.
• Make the slurry completely smooth before adding other ingredients. Run your fingers through it. If you feel any grains, keep stirring.
• Serve immediately. This sauce thickens as it cools and doesn’t reheat as smoothly as the first time around.

Variations

• Add a squeeze of lemon juice for a brighter sauce that pairs especially well with fish.
• Swap dill for chives or tarragon depending on what you’re serving it with. Each herb shifts the sauce toward a different flavor profile.