Hop Farm near Traverse City, MI

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Understanding Hops: Alpha and Beta Acids

2013 Homegrown Chinook

Hops, or Humulus Lupulus, are one of the key ingredients in brewing beer. Hops used for beer come from the female plant and the cones consist of water, total resins, essential oils, tannins, monosaccharides, pectins, amino acids,lipids, and wax.  Total resin (which makes up roughly 15% of the total cone weight) and essential oils (which make up .5% of the total cone weight), together hold the most value to brewers. While the essential oils contribute to the aroma and flavor of the beer, the total resin contains the alpha and beta acids.

Alpha Acids:
Alpha acids are the main source of bittering for beer and are measured by the percentage of total weight of the hop. But, alpha acids are not soluble in wort and impart no bitterness. During the boil, alpha acids are isomerized by heat, into iso-alpha acids. This conversion is slow and almost never completed. After a one hour boil, only 25-30% of the alpha acids have been converted into iso-alpha acids. Therefore, the longer the hops are boiled, the more iso-alpha acids are in the final beer, creating more bitterness. We calculate this by IBUs (International Bitterness Units). The gravity of the wort also has an affect on iso-alpha acid conversion. Higher gravity worts have a slower conversion of alpha acids to iso-alpha acids. This is why extract brewers that only boil 3-4 gallons of their wort and top off with water to reach 5 gallons, need more hops to reach the same IBUs as brewers that use full boils.

Michigan Summer Ale: Coriander Wheat Ale

Summer time in Michigan is all about being outside. Our winters keep us cooped up, and as soon as the weather turns for the better, Michiganders flood to the outdoors. For me, canoeing down the Huron River is my all time favorite weekend activity. So, I wanted to brew a beer that would be a great sidekick on the water. My goal is to create session strength, easy drinking, and Michigan inspired beer. 

Luckily for me I live near Adventures In Homebrewing which sells grain from Michigan Malt, a local organic "micro malting operation." 


American wheat beer comes to mind, when thinking about a light summer ales. I split the base malt 50% Michigan Malt 2-row, 50% Michigan Malt Wheat Malt, and added some Caravienne for some color and toasted nut flavors. (Just a note, I do consistently get a 3-5% drop in efficiency when using Michigan Malt).  I chose Saaz hops because of it's spicy, herbal characteristics that will accompany the citrus from coriander. The coriander is very subtle in this recipe. The small addition provides subtle hints of citrus and pine, but is not over powering. Coriander needs a little prep work to bring out the oil aromas and flavors. When using coriander, roast the seeds in a small frying pan. When there is consistent popping, remove the seeds form the heat, cool, and place them in a zip lock bag. Then take a rolling pin and aggressively roll over the seeds to crack their shells. This makes the 
coriander seeds much more aromatic and pungent. Finally, I decided to use a fresh culture of Bell's Oberon Yeast, to round out the flavors. Bell's Oberon Yeast is a little more complex than California Ale, or American Ale yeast. All together I am very pleased with how this beer turned out.

How to Culture Bell's House Yeast: culturing yeast from a commercial bottle

Bell's Brewery (in Kalamazoo, MI) is one of Michigan's largest and most successful breweries. Their two flagship beers, Oberon and Two Hearted Ale, are two of the highest rated beers in the country. Bells uses a proprietary yeast strain for their ales that is not available for homebrewers. In my opinion, Bell's Brewery produces very simple beers, but their house yeast creates an interesting, unique final product. So, in order to use their yeast in my homebrews, I need to go straight to the source.  Fortunately for homebrewers, Bell's does not filter their ales, therefore making it possible for to culture their yeast from their bottles.