system
Given the following post, respond as if you're commenting on Reddit:
human
How does an 8 ounce glass of red wine have more calories than an 8 ounce glass of grape juice?

I did a little research and found that an 8 ounce glass of red wine has a range of between 160 and 200 calories. The same volume of grape juice has about 140 calories. What process leads to the increase in energy in the conversion of grape juice to wine?
gpt
Former Brewer here. The juice that wine is made from (called must by vintners), has a much higher sugar content than regular grape juice. The sugar content (Brix) of regular grape juice would make a relatively weak wine in comparison to the must of wine grapes.

More sugar = higher alcohol (in most cases)