No, you should not put an unopened bottle of champagne in the freezer. Champagne, like other carbonated beverages, is prone to expanding when frozen, which can cause the bottle to burst or explode due to the pressure buildup.
If you want to chill a bottle of champagne quickly, there are safer methods to do so:
Ice Bucket Method: Fill a bucket or large container with ice and cold water, then submerge the bottle in the ice. Add some salt to the ice-water mixture, as this can help lower the freezing point and chill the champagne faster.
Chilling Sleeve: Use a champagne chilling sleeve or wrap the bottle with a damp cloth or paper towel and place it in the refrigerator. The moisture from the cloth evaporates and cools the bottle more rapidly.
Chilling in the Fridge: If you have some time, simply place the bottle in the refrigerator for a few hours or overnight.
Remember, once you open the bottle of champagne, you can put it back in the refrigerator or use a champagne stopper to keep it chilled and bubbly for a short period. If you don't finish the bottle, it's best to store it in the refrigerator with a proper stopper rather than freezing it.