When designing an IPA, what specific component or combination of chemical components in the hop am I looking for? I want to venture out more, and try new hop varieties in an IPA. Besides looking for the freshest hops, should I be looking at hop components such as, total oil, co-humulone, beta-acids, alpha-acids, myrcene, humulene, or farnesene?
Often times I can't find the classic IPA hops, such as, Simcoe, Citra, or Centennial. So I would like to know what exactly to look for in a hop variety before I buy it and run a test brew.
A lot of brewers look at myrcene content, but that really doesn’t tell the whole story. Some other components people are looking at include linalool, geraniol, nerol, and B-Citronellol, which apparently is a compound transformed from geraniol by brewers yeast. Hop analysis and resulting hop character in beer is a very complex subject, and I’m not sure there is one good answer at this point. I’ve had brews made with different hop varieties, where the analysis matches up pretty close, but the flavor profiles are completely different. And no offense to the hop suppliers’ literature, but I find their recommended substitutions to be very questionable.
So one of the best methods I've found is to taste other brewers beers that use the hops I'm interested in. Seriously, I find this so much more valuable than looking at a specification/analysis sheet.
Alpha acids definitely don’t tell the whole story-I’ve had 2 beers dry-hopped with hops at very similar high alpha acid levels, one had a huge hop presence and one had very little. So you need to be careful reading too much into the analytics, because there is more to it that really isn’t completely understood yet. In my opinion, we’re not really close to having a good understanding of the dynamics of hop flavor in craft brewed beer.
And, one last comment, hop flavor in beer is influenced by so much more than the hop variety itself-yeast variety looks to play a key role, as does fermentation temperature, pitch rate, aging temperature, where the hops are added, the beer style and the malts in the recipe, how the hops were harvested, how they were kilned, how old the hops are, storage conditions, and on and on.