You want faster ice cubes?

You want faster ice cubes?

Summers have come in India. And its a very common and frustration situation when you open the fridge and find the ice cube trays empty. People who can not compromise and want their drinks to be chilled, here is the thing to do for faster ice cubes:

Use Hot water. Yes, hot boiling water for making ice cubes. Hot water freezes more rapidly than cold. Also, hot water produces better quality clear cubes.

The phenomenon of hot water turning into ice faster than cold water is known as the Mpemba Effect, named after a Tanzanian student who observed his hot ice cream mix freezing more rapidly than the cold version.

Use BPA-free plastic trays, stainless steel, or silicone ones. Hot water can cause BPA leaching in certain plastics not rated as BPA-free. Using metal trays is advisable because of its little insulation.

Why hot water freezes faster than cold water?

A water molecule is made up of two hydrogen atoms and one oxygen atom which are bounded together by sharing of electrons, known as a covalent bond. Water molecules are then connected to each other by inter molecular force known as hydrogen bond. A hydrogen bond is a weak type of force that forms a special type of dipole-dipole attraction which occurs when a hydrogen atom bonded to a strongly electro-negative atom exists in the vicinity of another electro-negative atom with a lone pair of electrons.

According to the Nanyang study, these bonds are behind the Mpemba effect.

Normally covalent bonds will soften and lengthen as they are heated. But in water because of the unique properties of hydrogen bonds the opposite effect happens.

Hydrogen bond brings water molecules into close contact, and a natural repulsion between the molecules causes covalent bond to stretch and store energy. As the liquid warms up, the hydrogen bonds stretch as water gets less dense and the molecules move further apart.

The extra stretch in hydrogen bonds allows the covalent bonds to relax and shrink a little, giving up their energy. The process of covalent bonds giving up their energy is equivalent to cooling, so warm water should in theory cool faster than cold, which is Mpemba effect.

More importantly, the rate at which the energy in these shrunken covalent bonds released is dependent exponentially on how much energy was initially stored. Effectively, hot water has energy wound up like a spring which gets released when you begin to cool it, allowing it to cool and freeze faster.

Why people say it is not preferable to put hot food in fridge?

The rule of thumb to keep hot foods hot (60 degree or hotter) and cold food cold (4 degree or colder) to keep them out of the danger zone, which is any temperature in between.

It’s usually OK to put hot food in the fridge. As a matter of fact, it’s preferable. Despite some information to the contrary, putting hot food in the fridge won’t harm your appliance or affect the temperature of the foods around it.

Bacteria can grow on food within two hours unless it’s refrigerated, especially high-risk foods such as meat, poultry,fish, eggs and other dairy products.

Where you may run into trouble is if you have huge quantities of food in deep dishes, like soup in a massive stock pot.