1. Choose Your Equipment - When it comes time to puree a soup, our main choices are a blender, a food processor, or an immersion blender. Each has their pros and cons:
• Blenders - Blenders do a great job of pureeing soups. The only difficulty comes from transferring the hot soup to and from the blender itself, an annoying, messy, and potentially hazardous process. Blenders will also occasionally leave small chunks of soup unprocessed, especially older blenders.
• Food Processors - Food processors tend to chop up the soup into small pieces rather than actually pureeing it, leaving the soup with a slightly gritty texture and non-uniform pieces. Some of this can be helped with the tips below, but I've found that a truly silky puree is a little beyond the reach of most food processors.
• Immersion Blenders - If perfect creaminess is your aim, an immersion blender is a must-have item. I resisted its lure for years before finally giving in, and I haven't regretted it for a moment. There's no mess of transferring the soup; all the pureeing is done right in the pot. And the immersion blender mashes even the tiniest particles into oblivion. This is my new best friend when it comes to pureed soups.
• Other Equipment - In a pinch, you can use a potato masher to puree your soup or press the entire batch of soup through a strainer (or tamis). Both methods will require some muscle work, but will get the job done!
2. Soft But Not Mushy - Don't rush the cooking process and try to puree the soup while the vegetables are still hard or your soup will end up tasting gritty. You want the vegetables soft all the way through, but not so cooked that they fall apart into mush.
3. Adding Cream and/or Oil - Many recipes have you stir in the cream or last few tablespoons of oil once the pureed soup is back in the pot. Instead, try streaming some or all of it into the soup as it purees. This makes a better emulsion and gives the soup a creamier feeling in your mouth.
4. Add a Slice of Bread - This is one of those bits of kitchen magic that has to be tried to be believed. Add a slice of bread, torn into big pieces, to the blender or food processor along with the soup, and somehow this helps to make a more uniform puree with fewer chunks left behind. I usually do 1/2 - 1 piece of bread with each batch being pureed. (Added bonus, you won't need to add as much cream later on!)
5. Pass the Soup Through a Strainer - Set a strainer over your soup pot and let the soup drip through after its been pureed. This separates out any big chunks left behind by blender or food processor, which can then be re-blended. A plastic scraper will help push the soup through the strainer more quickly.
What other tips do you have for making perfectly pureed soups?