using old pellet hops

[apshaffer]

I found a bag of Centennial pellets in my freezer that are over a year old. On Beersmith, it says Centennial has a 'hop stability index' of 40, or 40% of the alphas are lost after 6 months. The Centennial was 9.2% to start.

Hops are harvested once a year in late summer. So If I buy some pellet hops in say April that are 10% AA, aren't they already over 6 months old (assuming they were harvested the prior season)? So right out of the gate my 10% AA hops are really only 6%?

I plan on using these Centennials, but I'm not sure how to figure out the alphas? I think I bought them last spring (april/may '11), which means they're from the 2010 season. For simplicity, I'm going to say they are 1 year old. By my math that means they are around 3.3% AA. Does that sound close?

 

[apshaffer]

Anyone?

 

[sweetcell]

nope, you're not close. the HSI measures loss at room temperature, exposed. if you had them air-tight in yout freezer then you've lost very little.

when the hops are first harvested and sealed, they're typically put in UV-resistant, nitrogen-flushed mylar bags. those go a long way in protecting them, and there is usually refrigeration involved as well.

so from your original 9.2%, you might be down to 8% IMO. depends on what state they were in your freezer (air-tight or not).