How to freeze and reheat soup
A couple of weeks ago, Steve, a Soup Chick reader, wrote to tell me he's planning a soup-and-sandwich fundraiser in the Fall, and he wants to make some soups ahead and freeze them. Though I've marked many of the soups on Soup Chick as make ahead and freeze recipes, he requested more detailed information about how to freeze soup. Steve, thanks for asking.
According to the United States Department of Agriculture, almost any food can be frozen. Almost any soup can be frozen, too, though some will lose a bit of texture in the process. When it comes to soup, that's not always terribly important, as most soups already have a kind of slip-slidey quality, and you can perk up a frozen soup by adding a few fresh ingredients (vegetables, pasta, cream) before you serve.
- When making a vegetable soup to freeze, undercook your vegetables a bit. If they're still crunchy when the soup goes into the freezer, they'll have better texture when defrosted. Potatoes can become a bit mealy, but soups with pureed potatoes freeze well.
- If your recipe calls for the addition of fresh tender herbs, such as basil or parsley, omit those prior to freezing, and add them when you reheat. More hearty herbs (thyme, rosemary, sage) often are added early in the cooking process, and they'll stand up to the freezer without losing their zing.
- Bean soups love the freezer.
- Brown rice and wild rice take to freezing a bit better than white or converted rice, though all rice will soften as it thaws.
- Pasta can get somewhat mushy, so either undercook it in the soup, or add pasta after you defrost and reheat.
- If your soup contains shellfish, you should make the soup base (without the fish) and freeze that. When you're ready to serve, thaw and reheat the base, and add fresh shellfish, which will take just minutes to cook.
- I don't know who started the rumor that you can't freeze cream-based soups. You can, but there are a few tricks to it. (See below.) Sometimes soups with a milk or cream base will separate during the freezing process, but you can whisk them back to health with a bit of fresh cream or an arrowroot slurry (arrowroot mixed with water). So, go ahead and make (and freeze) that in-season corn chowder.
- If your recipe calls for the addition of cheese just before serving, omit that prior to freezing, and add it during the reheating. Even though you can freeze cheese on its own, it will reheat at a different speed than the soup contents around it.
Rule of thumb: If you can freeze the components, you probably can freeze the soup.
Step One: The Big Chill
Before you can freeze your soup, you need to chill (the soup, not you). Never put hot food directly into the freezer; you'll riase the temperature of the freezer and endanger the safety of the food in it.
Remove the pot from heat. Let the soup sit for 20-30 minutes, uncovered. Stir occasionally to release more heat from the soup. When the soup has reached room temperature, it's ready to be packed.
If you're in a super hurry, you can set the pot of slightly cooled soup into a larger pot (or the kitchen sink) in a few inches of ice water (water with ice cubes). Don't put your pot directly from the stove into ice water, because even the toughest pot might crack from thermal shock. Once the contents are somewhat cooled, an ice water bath can speed the process.
If you live in a cold climate like New England, let Mother Nature help you cool your soup in the winter. I like to let the soup cool for 20-30 minutes in the kitchen; then, I set the entire pot outside on my porch to cool for another 30 minutes in the frigid air.
Step Two: Pack It In
After the soup is chilled to room temperature or below, transfer the soup into containers. What type of containers work best? Some people like to use Ziploc® heavy freezer bags, which take up less space in the freezer. I prefer sturdy food storage containers with tight-fitting lids, to minimize leaks and prevent the transference of any other smells from the freezer.
Be sure to leave at least half an inch of extra space in the container to allow the liquid to expand as it freezes. If you use bags, squeeze out as much air as possible, but don't overfill the bags. Remember to leave a bit of expansion space.
To prevent freezer burn, press a piece of plastic wrap directly onto the surface of the soup before you put the cover on the container.
Another favorite way to freeze soup is by portioning it into silicone muffin pans. When the soup freezes, squeeze the "muffins" into ziploc bags. [When you want a bowl of soup pop one or two of the frozen soup muffins into a bowl and reheat.]
If you're making a cream-based soup, pour off most of the liquid, and freeze the solid portion of the soup. When you reheat, add fresh cream or milk.
Please do not freeze soup in containers that are not specifically marked food-safe or freezer-safe.
Step Three: Deep Freeze
Once the soup is chilled and packed, label it with a marker or a paper label. Note the type of soup and the date.
To freeze soup in bags, set the bags on a cookie sheet and freeze in a single layer. When the soups are frozen solid, you can stack them in your freezer. Although I know many people who prefer this method, I've had a few unfortunate leakage episodes, so I prefer the containers.
Step Four: Heat and Eat
Note the dates on the soup containers in your freezer, and try to use your soups within 3 months (though many non-cream soups will keep as long as 6 months).
There are a few ways to defrost your soup. The best, and safest, is to let the container sit in the refrigerator overnight.
If the soup does not have a cream base, you can defrost in the microwave. My microwave has a defrost setting, though I seldom use it. Instead, I heat on medium, a minute or two at a time, until the soup is uniformly thawed; then, I heat on high to serving temperature.
To resuscitate a cream-based soup that has separated, first thaw the soup in the refrigerator overnight. If it's a pureed soup, toss it into the blender or food processor, or use an immersion blender. Then, transfer the soup to a Dutch oven or heavy stockpot, and heat gently on the stovetop.
If it's a soup with solids (chicken, vegetables, etc.), and you have frozen the solids separately, spoon the thawed solids into a heavy Dutch oven or stock pot. Add fresh cream or milk or broth, and whisk together.
Soups that have been frozen might lose a bit of texture, but they won't lose flavor.
Do you have any additional tips for freezing and reheating soup? What soups do you make ahead and freeze?