Pureed soups are a great way to keep warm and nourished during cold weather. With a wide variety of delicious recipes available, from silky cream of celery soup to traditional vichyssoise, it can be tempting to make this kind of meal a part of your regular routine. In fact, one might even be tempted to make a large batch of soup and can it for maximum convenience; however, this is not a wise choice. While many types of soup can safely be canned at home, pureed soup is an exception. Here's why canning pureed soup poses a risk to your health.
Soup that has been pureed is difficult to can safely due to both the texture of the liquid and the chemistry of its ingredients. The primary concern caused by these soups is their consistency. The result of pureeing soup is that it tends to make the resulting liquid very dense, and this density can make it difficult for the heat that sterilizes canned food to properly penetrate the entirety of the soup. In addition, pureed soups tend to consist primarily of vegetables, which have low acidity and can provide a breeding ground for botulism, a dangerous pathogen that causes serious food poisoning. Between these two factors, it is wise to find other methods of preserving this kind of soup.
How To Preserve Pureed Soups
The easiest alternative to canning soup that has already been pureed is to simply create soup bases that can be canned and then finish cooking them upon opening when you are ready to eat them. For example, if you wish to preserve a smooth and creamy butternut squash soup, you can prepare the soup by following all of the recipe steps up until blending the soup. You will be able to safely can the soup in its chunky format and then puree it into its final form on the day you wish to serve it.
If this approach does not appeal to you, the next best option is to skip canning your pureed soup and freeze it instead. To do so, wait for your soup to cool and then add it to an airtight container with room left over for the soup to expand. In the freezer, you can expect most soups to last for up to three months.
Read the original article on Tasting Table.