Milk watcher

A milk watcher, milk saver, pot watcher, pot minder, milk guard, or boil over preventer is a cooking utensil placed at the bottom of a pot to prevent boiling over of liquids, and especially the burning (scorching) of milk.

A milk watcher is a disk with a raised rim, and is notched on one side (see images). Some milk savers are designed so they can be used with the obverse or reverse side facing up, so they appear to have two notches. The interior of the disk is not level; it slants upward toward the notched side creating a space just behind the notch where water vapor can collect. Water vapor is trapped under the Milk Saver causing the notched side to rise up, releasing the water vapor at the same time circulating liquid around the base of the pot and making a rattling noise.^[1]

How it works

Normally, boiling water does not boil over. When fats, starches, and some other substances are present in boiling water, for example by adding milk or pasta, boiling over can occur. A film forms on the surface of the boiling liquid; for example, cream can boil over as milk fat separates from the milk.^[2] The increased viscosity of the liquid causes the steam bubbles to form foam trapped under the film, pushing the film up and over the lip of the pot, boiling over. A milk watcher disrupts this process by dispersing heat from the burner more evenly, circulating liquid around the bottom of the pot, collecting small bubbles of steam under the milk watcher into a large bubble and releasing it in a manner that may puncture the surface film, and finally the milk watcher itself may absorb some excess heat that would have gone into producing steam bubbles.

The device rattles alerting the cook that boiling is occurring. By circulating fluid the device might also prevent anything from depositing on the bottom of the pot and eventually burning.^[3]

Alternatives

These alternatives to a milk watcher may not address the burning of material deposited on the bottom of the pot:

• Being attentive, lowering the heat, and stirring the fluid with a spoon.
• Placing a spoon across the top of the pot.^[4]
• Placing a long spoon into the pot.^[5]
• Blow air onto the fluid, for example with an electric fan such as the Boiling Minder.^[6]
• Spray water onto the surface of the boiling fluid with a spray bottle.^[7]

References

External links

Media related to [//commons.wikimedia.org/wiki/Category:Milk_watcher Milk watcher] at Wikimedia Commons

• Why does Milk spill over when it Boils?
• Why does milk boil faster than water?
• What is a Boil Over Preventer