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 apart from each other. As ancient civilizations began to purposely cultivate hops for use in the making of beer circa 1079, they only had a rudimentary understanding of its 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 are used towards 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.
Conversely, wet-hopping is when fresh whole cone hops are picked and then used in less than 24 hours to ensure the resin is still at its optimal level. As hop harvesting alone 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.” Their Northern Hemisphere Ale was one of the first wet-hopped ales produced in the U.S. As they were the first commercial brewery to make use of Cascade hops way back in 1980, they decided to pay tribute to those and one of Oregon’s other big-name hops, Centennial, and showcase their wonderful aromatics.
Northern Hemisphere is brilliantly-balanced ale. The color is liquid copper like a brand-new penny. The bonus oil from the fresh hops let the voluminous head stay around for days while leaving behind lacing like the vines that spawned them. 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. Excellent carbonation yields a rather creamy texture while the bitterness is noticeable but not overbearing.