Subject: What's process called that turns red wine to white when add ammonia?

My mom and I were watching a cooking show and the guy put ammonia into a glass 
of red wine and the wine turned white. He said what the process was called but 
we didn't catch it.  I was wondering if ammonia would take the color out of 
grape juice.

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