Enjoy a science lesson with your Northern Hemisphere Harvest Ale

For the sake of today’s discussion, I’m going to have to get all “nerd-speak” on the readers at home. We’ll be talking about hops and their role in the beer-making process, which means I’m about to break out some science on you. Well, me and my trusty copy of Charlie Papazian’s “Joy of Home Brewing.” Let’s go dork out for a while, shall we?

Hops, or Humulus lupulus, grow in massive, long vines, like mutant string bean plants. Because pollinated seeds don’t work in the brewing process, male and female plants are kept separate. As ancient civilizations began to purposely cultivate hops for use in the making of beer circa 1079, they had only a rudimentary understanding of their preservative qualities. A few centuries and scientific advancements later revealed that it is hops’ alpha oils that act as an anti-bacterial agent, limiting spoilage.

About those hop oils: Hops contain chemical compounds known as alpha and beta acids. Alpha is responsible for imparting bitterness to the beer. The longer the hops boil in the wort — the mixture of water and malted grain, the more bitter the finished product. Beta acids, however, can’t achieve isomerisation, or molecule transformation, like alpha acids do. Instead, their role is as an aromatic agent, and hops high in beta acids are used toward the end of the boil. If they’re used after the boil — when the beer is cooling — it’s a technique known as dry-hopping.

Wet-hopping is when fresh, whole-cone hops are used within less than 24 hours of picking to ensure the resin is still at its optimal level. Hops harvesting is an arduous task. Add to that the cost of quickly plucking, packing and shipping the little guys, — usually by air freight — and one can see why most brewers don’t bother with wet-hopping.

Sierra Nevada isn’t “most brewers.” Its Northern Hemisphere Harvest was one of the first wet-hopped ales produced in the U.S. As it was the first commercial brewery to make use of Cascade hops way back in 1980, the brewery decided to pay tribute to those and one of Oregon’s other big-name hops, Centennial, and showcase their wonderful aromatics.

Northern Hemisphere is a brilliantly balanced ale. The color is liquid copper, like a brand new penny. The bonus oil from the fresh hops lets the voluminous head stay around for days while leaving behind lacing like the vines that spawned the hops. Orchards of grapefruit and pine scents waft out of the beer, with a dusty touch of malt. Much more of the same on the palate — loads of citrus, flowers, grass and resin, with a solid malt backbone that’s both bready and caramel-sweet. And excellent carbonation yields a rather creamy texture, while the bitterness is noticeable but not overbearing.

Hopjacks Pizza Kitchen & Taproom, 10 Palafox Place. 497-6073, or visit www.hopjacks.com.