Ice Spikes: Rare Freezer Formations

This is a new one to me: probably because this household doesn't use distilled water for ice cubes.

"Ice Spikes"
SnowCrystals.com (February 1, 1999)

"... Strange things you can find in your freezer ..."

"Ice spikes are odd ice structures that occasionally grow out of ice cube trays. Unlike some of the strange things you might find growing in your refrigerator, ice spikes are made of nothing but ice. Ice spikes are the result of physics, not biology.

"Here are some pictures I took of ice spikes that grew in my kitchen freezer. They look a lot like the limestone stalagmites found in caves, although there was no water dripping inside my freezer when these formed.

"To see your own ice spikes, make ice cubes in an ordinary ice cube tray, in an ordinary household freezer, but using distilled water, which you can buy in most supermarkets for about a dollar a gallon. We've tried several different freezers, and almost always got some ice spikes to grow...."

There's some interesting physics involved here. Also, a way to add a little spirit of adventure to making ice cubes: will they form ice spikes this time? Are the freezer conditions right?