Blending and Processing Hot Liquids

Homemade Tomato SoupOne mistake we’ve made more than once is the blow-back and spills from trying to blend hot liquids, particularly tomato soup. What a mess! Here are a couple of things we’ve learned about this.

  • When blending a hot liquid, remove it from the heat and allow it to cool for about 5 minutes to vent some of that built up energy.
  • Carefully transfer the liquid to your blender or food processor, filling it no more than half full.
  • When using a blender, loosen the small filler cap in the lid, or lift up the corner of the lid away from you to let steam vent. This avoids the vacuum effect that creates heat explosions and blasts soup all over. The hot liquid, the vibration, and the steam will all always conspire to blow the lid off, and many folks have coated their ceiling with hot soup. You have to hold the lid down firmly when pulsing soup.
  • Use a cloth towel folded several times to protect your hands from the hot liquid. Press down on the towel on the top of the blender to catch any droplets, pulse a few times, then process on high speed until smooth.

Blending While Cold
3-blade blenderInstead of blending hot liquids, try blending the tomatoes together with your sautéed, and cooled, aromatics before assembling the soup. This step might raise an eyebrow at first, but sautéing the onions and garlic before blending ensures the bite of those aromatics is cooked out without overcooking the soup. Some cooks say that the veggies resist breaking down at this stage, leaving tiny bits behind, making the soup a little more grainy than desired. Personally, we don’t mind a little texture.

But, blenders, generally speaking, tend to get things smoother than processors or handhelds, so you might employ the blender for this process, and use small batches and longer blends to achieve a better texture. There’s another option. You might prefer doing the cooking a day ahead, letting things cool off, and then using the blender before reheating the next day when the flavor may actually be improved.

A Word About Blenders
We’ve had, and worn out, many blenders over the years. This is our current home model. It has three blades on the shaft for small to big jobs, a vent/pouring lid in the top, suction cups to keep it in place on the counter while conquering tough jobs, a measuring scale on the 72-Ounce Pitcher, and a motor powerful enough to handle mixing bread dough! It also has a 64-oz. food processor bowl. This has been a workhorse, and we are very pleased with its performance.

Larry with Pot of Hot BrothBlending and processing hot liquids can be fairly dangerous work, so you need to think ahead to protect yourself. Recommended practices are: 1) Use a lot less liquid in the blender than normal. Do batches if needed, 2) Vent the lid so the steam can escape, 3) Cover the lid with a kitchen towel as you start to insure there’s no spray, and 4) Start the blender slow and then speed it up. Be safe! Try not to join the soup-on-the-ceiling club!