1. Simmer it down
What goes wrong: Thin soup is often just soup with too much water.
The fix: Take the lid off and simmer gently for 10 to 15 minutes, stirring now and then. Water evaporates, flavor concentrates, and the soup thickens without adding anything. Taste before you add more salt, because reducing makes it saltier.
2. Blend some of it
What goes wrong: Stirring in flour or starch at the end is the first thing most people reach for, and it can taste pasty.
The fix: Scoop out a cupful or two of the soup, including plenty of the solids, blend it smooth, and stir it back in. This works especially well with potato, squash, bean and vegetable soups, and it thickens with the soup's own flavor. An immersion blender lets you pulse right in the pot.
3. Mash the potatoes or beans
What goes wrong: You do not always need to blend anything.
The fix: Press a few spoonfuls of the cooked potatoes, beans or lentils against the side of the pot with a fork or masher. The starch released thickens the broth and the soup stays chunky.
4. Use a cornstarch slurry
What goes wrong: Dropping cornstarch straight into hot soup makes lumps.
The fix: Mix a tablespoon of cornstarch with a couple of tablespoons of cold water until smooth, stir it into the simmering soup, and cook for a minute or two until it thickens. Add a little at a time, because it keeps thickening as it sits. Arrowroot works the same way.
5. Make a quick roux or flour paste
What goes wrong: Plain flour sprinkled in raw leaves a floury taste.
The fix: Cook equal parts butter and flour in a small pan for a minute or two, then whisk in some hot broth from the soup and stir that back into the pot. Or knead equal amounts of soft butter and flour into a paste and whisk in small pieces until the soup thickens, simmering a couple of minutes after each addition.
6. Add something starchy
What goes wrong: Sometimes the quickest fix is already in the pantry.
The fix: A handful of instant potato flakes, a spoonful of cooked rice, a few rolled oats or a slice of torn bread simmered in the soup and then blended adds body fast.
7. Cool it before it goes in the freezer
What goes wrong: Putting a hot pot straight into the freezer warms everything around it and can leave the middle of the soup warm for a long time.
The fix: Let the soup cool, then chill it in the fridge. Cooling it in shallow containers or in small portions speeds this up a lot.
8. Freeze it in single portions
What goes wrong: A big frozen block means thawing the whole thing even when you want one bowl.
The fix: Portion the soup before it freezes. Freezer trays with set portion sizes, muffin tins, or freezer bags laid flat all work: freeze until solid, then pop the blocks out and store them together in a bag. Flat bags also stack neatly and thaw quickly. Label the bag with the soup name and the date.
9. Leave room for it to expand
What goes wrong: Soup grows as it freezes, which can crack rigid containers or split lids.
The fix: Leave a little space at the top of any container, and do not fill bags to the brim. Let the air out of bags before sealing.
10. Hold back the dairy, noodles and rice
What goes wrong: Cream can separate and noodles or rice turn mushy when frozen in the soup.
The fix: Freeze the base without them. After thawing, reheat the soup, then stir in the cream at the end and add freshly cooked noodles or rice. A splash of broth loosens soup that thickened in the freezer.
11. Thaw it gently
What goes wrong: Reheating frozen soup too fast scorches the bottom and leaves the center cold.
The fix: Thaw it overnight in the fridge when you can. Otherwise warm the frozen block in a covered pot over low heat with a splash of water or broth, stirring now and then, until it is steaming hot all the way through.
A tool that makes freezing portions easy
Silicone freezer trays with fixed portion sizes are the simplest way to do step 8. The Souper Cubes 2-Cup Tray has four 2-cup wells with printed fill lines, which is about one bowl of soup per block, according to the product listing. We have not used it ourselves; we compared it with other trays from specs and owner reviews in our silicone freezer tray guide.
See the Souper Cubes 2-Cup Tray on Amazon (affiliate link) · Read the silicone freezer tray guide
Recipes that use these tips
These soups put the thickening and freezing tips to work:
- Roasted butternut squash soup: blend part of it for thickness.
- Potato leek soup: mash some of the potatoes to thicken.
- Creamy tomato basil soup: stir the cream in after reheating.
- Homemade chicken noodle soup: freeze the broth, add fresh noodles.
- Beef barley soup: a hearty soup that freezes well.