Baked hard liquor is slightly higher in alcohol content. This is shochu, which I'm guessing is heated in some way during its production.

Shochu is a type of Japanese traditional hard liquor. It's a distilled spirit made from ingredients like sweet potato, barley, rice, buckwheat, and sugar cane.

The reading for 焼 and 酎 are the on'yomi readings, but you didn't learn the reading for 焼 yet. That's okay, because if you know the (also English) word Shochu, you'll be able to remember the reading for this one as well too.