Re: What's process called that turns red wine to white when adding ammonia?

The first thing to explain is that red white is red in colour because it has chemicals in called anthocyanins. These anthocyanins are natural dyes and are found in a whole heaps of other foods.

The strange thing about anthocyanins are they are extremely sensitive to acids and bases. Now the normal colour of the chemical is red, but as you noticed if you added ammonia, which is a base,then it turns to clear or pale green. An interesting thing you can try at home, is repeat what the guy on TV did and once your wine has turned clearish then add vinegar. Any type will do but the clear table variety will be better. By adding the vinegar, which is an acid you can turn the clear wine back to red!

One interesting point is that the colour of red wine, all comes from the skin of the grapes, if you skinned every grap and made the wine from the flesh of those grapes it wouldn't be red at all.

The last thing you asked was whether it would do the same thing with grape juice, well it certainly will, you could also use cherry juice or red cabbage, they all have the same anthocyanins in them that make them red.

Well hope that answers all your questions

David Barker