What does it mean if a broth breaks" when making a soup (like fats/emulsion separate) and how can you fix or prevent that?"

Question

Did your creamy soup 'break'? Learn what causes this separation to happen and what you can do to fix it or prevent it from happening again.

Answer 1

A broth 'breaks' when the fats separate from the liquid, creating an unappetizing oily layer. You can often fix it by whisking in a starch slurry (cornstarch or flour mixed with cold water) or by emulsifying with a blender.

Detailed Explanation:

When making soup, especially those with a significant amount of fat (like bone broths or cream-based soups), the emulsion can sometimes destabilize, causing the fat to separate. This is what's meant by the broth 'breaking.' Several factors can contribute to this:

1. Temperature Fluctuations: Rapid changes in temperature, especially overheating, can cause the emulsion to break down.

2. Acidity: Adding acidic ingredients like lemon juice or tomatoes too early in the cooking process can destabilize the emulsion.

3. Fat Content: Soups with a very high fat content are more prone to breaking.

4. Lack of Emulsifiers: Emulsifiers like starches or proteins help bind fat and water together. If there aren't enough natural emulsifiers or if they've been broken down by overcooking, the broth can break.

Here's how to fix a broken broth:

1. Starch Slurry: Mix 1-2 tablespoons of cornstarch or flour with an equal amount of cold water to form a smooth slurry. Gradually whisk the slurry into the simmering soup. The starch will help re-emulsify the fat and liquid.

2. Blending: Carefully transfer the soup to a blender (or use an immersion blender) and blend until smooth. The high-speed blending will help re-emulsify the fat. Be cautious when blending hot liquids; vent the blender lid to prevent pressure buildup.

3. Add More Liquid: Sometimes, adding a bit more broth or water can help re-establish the emulsion, especially if the soup has become too concentrated.

Pro Tip:

To prevent a broth from breaking in the first place, avoid high heat and rapid temperature changes. Add acidic ingredients towards the end of the cooking process. If making a cream-based soup, temper the cream by gradually adding small amounts of the hot broth to the cream before adding the cream to the entire pot. This helps prevent curdling and separation.