Can I use an unopened cake mix over a year past the Best By date?

It's generally not recommended to use a cake mix that's over a year past the Best By date.

Here's why:

* Loss of quality: While cake mix itself won't "go bad" in the traditional sense, ingredients like leavening agents (baking powder, baking soda) can lose their potency over time. This could result in a cake that doesn't rise properly, is dense, or has a flat taste.

* Changes in texture: The flour and other ingredients in the mix may also change in texture, resulting in a cake that is dry or crumbly.

* Taste alteration: The flavor of the mix can be affected by the aging of ingredients, potentially making the final cake taste stale or off.

However, there are a few factors to consider:

* Storage conditions: If the cake mix was stored properly in a cool, dry place, it might still be usable.

* Your risk tolerance: If you're willing to experiment, you can try using the mix. Just be aware that the final product might not turn out as expected.

If you're unsure, it's always best to err on the side of caution and use a fresh cake mix.

You can always test a small amount of the mix to see if it still reacts properly to water and leavening agents. If it does, then it might still be good to use.