A poster in Reddit’s cooking forum tells an all-too-familiar tale. She makes lentil soup in her Instant Pot, and despite following the directions to a T, ends up with a watery, thin finished product. Her solution? Add plain instant mashed potatoes (which are essentially just dehydrated potatoes) to the finished soup recipe as a thickening agent. Simple? Yes. Incredibly effective? You bet. This trick works because the instant mashed potatoes are naturally starchy and therefore are similar in form to other commonly used thickeners, such as cornstarch, only without the clumps. After her post went viral with 870 comments and an 85 percent upvote from community members, the original poster went back to add some additional tips. She points out that it’s wise to consider what type of soup you are making before adding the dried potato. For example, a delicate miso soup might not be the right candidate, while a potato leek or cream-based soup could work perfectly. You could always test the combo out on a small portion of soup before altering your full batch, just to be on the safe side.
Other Effective Ways to Thicken Soup
Make a Roux
While the tater hack is a good one, it’s not the only way to thicken a soup. If you don’t have instant mashed potatoes on hand or are looking for another way, try making a roux. Whisk a few tablespoons of flour or cornstarch into a little water or broth, then whisk that mixture into the soup itself.
Give It a Whirl
Another option is to puree a few cups of the soup—broth, veggies, and anything else—and then pour it back into the main pot (you can also use an immersion blender). This will thicken the texture by way of aeration without adding anything extra.
Add Starchy Ingredients
Adding rice or lentils, for instance, will seriously beef up a lackluster soup.
Stir in Something Creamy
Finally, you can always add yogurt, cream, or coconut milk to your soup to get that creamy, thick texture you’re looking for.
