It wasn't until (Louis) Pasteur that we knew how wine was made. Prior to that, it was like magic. In low-acid situations, you'd stick your nose in it and it would be disgusting.

When you make lemonade, you add lemon not just for the flavor. Even Kool-Aid has acid.

Make up some sugar water. Ten percent sugar is about what Kool-Aid is. Taste it. See how much you like it. Then add some lemon juice and do the same thing.

Soft drinks are very acidic. When I was a child, I remember my parents using Coke to clean out a radiator.

More sugar will make it taste less acid.

That's what you people never understand," said Rincewind, wearily. "You think magic is just something you can pick up and use like a, a -"

"Parsnip?" said Nijel.

"Wine Bottle?" said the Seriph.

"Something like that," said Rincewind cautiously, but rallied somewhat and went on, "But the truth is, is -"

"Not like that?"

"More like a wine bottle?" said the Seriph hopefully.

"Magic uses people," said Rincewind hurriedly. "It affects you as much as you affect it, sort of thing. You can't mess around with magical things without it affecting you. I just thought I'd better warn you."

"Like a wine bottle," said Creosote, "that -"

"- drinks you back," said Rincewind.