Mushroom Soup Concentrate

This is the homemade answer to that ubiquitous red-and-white can of condensed mushroom soup that lurks in every American pantry. Real fresh mushrooms (a full two pounds), real butter, real broth, no preservatives or modified food starch. The flavor difference is genuinely shocking: deeper, mushroomier, less salty, and free of that vague tinned aftertaste.

The technique is essentially a roux-thickened veloute. Onion, celery and parsley sweat in butter to build aromatic depth, then sliced mushrooms join and release their water as they cook. Flour goes in next to coat everything, and a slow pour of broth turns it into a thick, glossy concentrate.

It’s called a concentrate because that’s how to use it. Spoon it into casseroles, green bean casseroles, chicken pot pies and tuna noodle bakes wherever a recipe calls for canned cream of mushroom. Or thin with milk or cream for a proper bowl of soup.

Pro Tips

• Use a mix of mushrooms if you can. Standard white button alone is fine, but adding cremini, shiitake or portobello deepens the flavor dramatically.
• Don’t wash the mushrooms under running water. They’re sponges and absorb moisture that will make the soup watery. Wipe with a damp cloth or use a mushroom brush.
• Slice cap and chop stems separately. Stems are tougher and benefit from chopping smaller so they cook through; caps slice prettier.
• Stir the flour in until fully coated and cooked, about 1 minute, before adding broth. Raw flour gives the soup a pasty, starchy taste.
• Pour the broth in slowly while whisking. Dumping it all in causes lumps that won’t whisk out.

Variations

• Use vegetable broth instead of beef or chicken for a vegetarian version.
• Stir in 2 tablespoons dry sherry or Madeira at the end for a French restaurant-style depth.
• Replace half the broth with heavy cream for a richer, more luxurious soup that works as a sauce for chicken or pork.