I keep my Brown Sugar Bourbon in the freezer, because it tastes better cold and doesn't freeze. I only drink a couple BSBs over ice per month, but when my arthritis is acting up, it makes a good general anaesthetic.
Yesterday I had one with dinner, and it tasted really good so I poured more into my glass after dinner. I couldn't finish the second one. I stuck it in the freezer.
This morning it was frozen. Apparently there was enough water from the half-thawed ice cubes to cross over some threshold and the whole snifter became a mushy ice cube.
Isn't science amazing?