The Brilliant Butter Hack To Prevent Water From Boiling Over

We've all hit the boiling point in the kitchen. You throw a pot of water onto the stove with some potatoes, pasta, or rice and turn your back. Suddenly, you hear a loud sizzle and spin around to see your burners soaked and your pot missing half its water content. Luckily, there's a way to prevent this from happening besides babysitting the pot and wasting precious time in the kitchen. In fact, all this hack involves is a stick of butter.

Coating the rim of a pot of boiling water with a thin layer of butter is usually enough to stop a hot water disaster in its tracks. That's because butter is basically just fat, which acts as a naturally hydrophobic barrier that helps pop the bubbles that float up to the surface, preventing them from expanding into a foamy mess. Likewise, simply adding a slice of butter to the pot or pouring some oil on top of the surface of the water will also help stop any over-boiling, but it's also riskier and potentially messier.

Adding butter to a pot full of boiling water is a trick that has been recommended for literally decades, if not longer. As proof, there's an entry from a cookbook published in 1923 that elegantly states that "butter acts the same as oil on troubled waters and keeps it calm and manageable." In a more scientific sense, we know that this happens because of the hydrophobic nature of fat (which butter is primarily made from). The makeup repels water and traps the surface tension that would otherwise boil over. 

Water on its own will usually just boil until it evaporates, but adding more ingredients to the pot will create more surface area for bubbles to form, making a mess. In addition, the starches inside items like pasta and potatoes prevents the bubbles from bursting, leading to layers of hot foam that eventually surges over the lid of the pot.

Butter, or even oil, on the other hand, helps pop these bubbles that collect on the surface of the water and prevent the foamy buildup.

Adding olive oil to a pot of boiling water will have the same effect, but it's not necessarily the best practice. Even with butter on the rim, there's always a risk of a spill, and an oily surface will make the mess more slippery and, more importantly, more dangerous if it hits the flame of the burner and helps ignite it further. If you want to use oil or cooking spray, just blot a dab on a napkin and wipe some around the rim the same as you would with a stick of butter.

Other methods of preventing a boil-over all similarly help pop those bubbles faster so they don't collect on the surface. Like butter or oil, the heat-resistant properties of a wooden spoon resting on top of the rim will destabilize the bubbles and pop them before the water spills over. Picking a bigger pot helps, too, since a larger surface area will allow for more space for the bubbles to collect and eventually burst. And, while keeping the lid on a pot will help heat the water up faster, the trapped steam from the bubbles will make it boil over sooner. If you're in a hurry, keep the lid on until the water reaches a rolling boil, then leave it off when you're cooking your food.