[barttenbrinke]

We used to put a marble and water in an empty camera film roll canister (transparant). Freeze in the freezer and flip over. If you come back and the Marble is frozen on the bottom of the canister: don't eat anything! #lowtech

[mcpherrinm]

I've always just put an ice cube in a ziplock bag. If it isn't square, that means it's melted & refrozen. The marble trick seems like it's probably more sensitive, but I also don't have marbles and film canisters laying around.

[win_ini]

Low effort too: I just look at the ice in the bucket rose if it's frozen in a blob - or a pool of frozen water at the bottom. :)

[manyxcxi]

This is a tip EVERYONE should know and I still do this! I use a half filled bottle of water, a small rock, and mark safe/not safe so anyone who's not me knows which way it should be.

Pretty sure it was my great-grandpa who taught me that.

[detaro]

I remember that my parents' old freezer had something like this built-in (using colored liquid instead of the marble, but the principle is the same). Seemed like such an easy and obvious feature.

[RankingMember]

I love low-tech solutions like this.