Hot liquid in a closed jar continues to produce steam. When the blade starts spinning, liquid is flung against the walls, the trapped steam expands rapidly, and the lid is pushed upward. The result is not just spilled soup; it is boiling liquid hitting your face and hands. That is why the jar is filled halfway, the plug in the center of the lid is removed and loosely covered with a folded towel, and you hold the lid down through the towel and start on low speed. Some high-speed blenders, however, require the plug to stay in place with hot liquids; if your blender's manual says otherwise, follow it.
A hot liquid continues to produce steam even after it has been removed from its container. In an open pot, the steam rises freely and goes unnoticed. A blender jar, however, is a narrow container with a lid; steam from the hot soup inside fills the jar and has nowhere to escape. Steam is the same substance in a much larger volume, so it quickly creates pressure in an enclosed space. Even before the blade spins, simply closing the lid causes pressure to start building inside the jar.
Once the blade starts spinning, things escalate. The rotating blade flings liquid against the walls, suddenly increases its surface area, and multiplies evaporation. At the same time, the liquid rises in a vortex. Steam trapped under the lid pushes against it along with the rising liquid, and the lid can lift even if someone is pressing down on it by hand. What comes out is not a warm splash but liquid close to its boiling point; hitting the face or hands can cause serious burns. It can all happen in one or two seconds.
The first precaution is the volume. Fill the jar with hot liquid no more than halfway; the space above it leaves room for both the rising liquid and expanding steam. Blending the same soup in two batches is always faster than letting it overflow in one batch. The second precaution is the lid: most blender lids have one removable measuring cup or plug in the center. Remove this piece and loosely cover the opening with a folded kitchen towel; the towel catches splashes while allowing steam to escape.
The third precaution is speed. Do not start the appliance directly on high; run it at the lowest speed, then increase the speed gradually after the liquid starts moving. A sudden start can send still liquid upward all at once. If you need to hold the lid down by hand, use a folded, thick towel rather than a bare hand, and keep your hand over the center of the lid. If possible, let the jar cool a little before filling it; letting boiling soup stand for a few minutes significantly reduces the risk.
An immersion blender almost never has this problem, for a simple reason: the pot is open, steam rises freely, and pressure does not build up. That is why the safest way to blend hot soup is to put the immersion blender directly into the pot instead of transferring the soup to a blender. With an immersion blender, too, start it only after the blade head is fully submerged in the liquid, or it may splash. Blenders with glass jars are lower risk when the manufacturer says they are heat-resistant, but the same fill-level and lid rules still apply.
Comments (1)
Sıcak çorbayı blenderda çekerken kapak fırladı ve mutfak baştan aşağı çorba oldu, elim de yandı. Bu uyarıyı daha önce okumak isterdim.