If a bottle of wine is 10.5 alcohol what proof that?

You're likely asking about the "proof" of a wine that is 10.5% alcohol by volume (ABV).

Here's how to calculate the proof:

* Proof is double the ABV: So, a 10.5% ABV wine is 21 proof.

Important Note:

* The term "proof" is primarily used in the United States for spirits (liquor). Wine is typically labeled with its ABV percentage.

* You might see "proof" used for wine in some informal contexts, but it's not the standard way to express its alcohol content.