I found two extract kits in my basement I had forgotten all about. I purchased then November or December of 2015. I still had the yeast in the Northern Brewer shipping box. The basement stays about 62 deg in the Winter and 65 in in the Summer. We did have an incident this summer that may have allowed the basement to get up into the 70's. I will replace the yeasts. One is a Dry Irish Stout and the other is a Big Honkin' Stout. I plan to brew one of them this weekend. I'm not sure of the shelf life. Think they are any good?