why is homemade ice different from other ice?


Any time I’ve ever made ice at home the ice cubes are opaque – this is the case in different houses. But ice I get in restaurants, cafes and bars the cubes are always clear.
Anyone know the reason?

In: 2

The opaqueness is from minerals in the water because at home you just use water from the tap. If you want clear cubes you can use distilled or filtered water.

It’s mostly air bubbles and some impurities trapped by freezing the ice very quickly. There are ways that you can freeze the ice to make it clear, but it mostly involves taking longer to freeze it, so unless you have a particular need to improve the aesthetics of your ice, there isn’t much reason to do it.

Cloudiness is often due to entrapped air dissolved in the water that form microbubbles as the water freezes.

Fill a glass bottle with water, it will probably have some initial cloudiness, but that will rise to the top and dissipate.

Now wait an hour or so, bubbles will form on the sides as more air comes out of solution. Thump gently to knock those bubbles out, then carefully pour into an ice tray, the ice will be much clearer.

The main culprit is your faucet aerator, which, as its’ name implies, mixes air into the water stream.

Restaurant Ice machines don’t use an aerator.

Home-made ice freezes from the outside in. There’s dissolved air in the water but it can’t escape once there’s a clear layer of ice all around, so you get a cloud of air bubbles forced out of solution in the middle of the cubes. What you can do instead is fill an insulated container with water and put it in the freezer with the top open. Then it will freeze from the top down giving a thick clear slab of ice at the top. Pull this layer out before the water freezes all the way to the bottom and you get clear ice.