What is the shelf-life of MTG?

[vtoodler]

I've got a 32 ounce bottle of MTG from May 2009. I don't know if I should still use it, or if it may be too old now.

What is MTG's shelf life? How long have you used a bottle of it?

 

[nissi]

Here's the people who make it, call and ask them... : http://www.shapleys.com/