I have some Chinook hop plugs that I’m thinking about using. They’re unopened and completely vacuum packed (no space for air inside), and they’ve been in my freezer since I bought them.
They’re the 2006 crop, packaged in October of 2007. I wouldn’t use leaf hops that were this old, but I feel like the plugs keep much better. Any opinions?
I’d say there’s a decent chance they’re fine to use. Open 'em up and smell 'em.
+1
Open them up and smell them…if they smell good…use them. If they are vacuum sealed they are protected from most of the dehydration and oxidation that would have damaged them if they weren’t properly packaged. The key is in the aroma.
While we’re talking about it…
How long do hops last? I have some whole leaf hops from my hop harvest last year (2009) that have been sitting in my freezer. Would these still be good for brewing? What should I look for to see if the hops are “past their expiration date”?
If O2 is removed from the packaging and the hops are stored in a freezer, you can easily keep them good for several years. To judge iof they’re still good, smell them. Typically, if they smell “cheesy”, they’re no good.
Vacuum packed hops in an O2 barrier bag will last 2 years with not much degradation. The AA is going down, but in a freezer you are keeping this to a minimum.
If the hops are not vacuum packed, and in a ZipLoc, they might only last a month according to the guys at Gorst Valley hops. ZipLocs are not barrier bags, O2 difusses through.
…it’s time to make some Belgians 
What about the food saver bags?
That’s what I use.
The guy from Gorst Valley said those are O2 Barrier bags.
Well if the zip-loc rumor is true, I might have some cheesy hops waiting for me. Bummer…
++1
Also, the utilization may have degraded a little too. But if they have been in the freezer the whole time probably not by much. I have used hops that were 1+ years old and stored in the freezer for an IPA which turned out as a Pale Ale.
Of they smell funky you can always use them for a lambic! Just make sure you boil long, 4-5 hours, and the smells should boil off.
FWIW, I keep my pellet hops in the original vacuum bag and a ziploc. I’ll press out as much air as I can and wrap them tight, then put them in ziplocs in the freezer. Not as good as original packaging, but better than nothing. It seems they last quite a while this way. That being said, I need to clean out and toss some old hops in the freezer. Another reason for kitting it - no hop leftovers!