I was given 10 gallons of homebrewed mead in a carboy. It was made by my brother-in-law and his friend almost 10 years ago. His friend moved away and he's kept the mead in the carboy, in a box (so it's not really exposed to light) for this entire time in his garage.
1) is it safe to drink? 2) if possible, how do I know? (ie what should I look for) 3) is there anything I should do prior to opening the carboy?
Background: I have homebrewed once, and although I was successful it was done with someone who was experienced. I inhereted all his equipment along with the mead and I need to decide what to do with this mead (he said it was ~14%abv before I start to organize and clean everything so I can learn from scratch.