Hops play 3 important roles in the making of your beer. They are used for adding 'aroma', 'flavor' and 'bitterness' to your beer recipes depending on when and for how long they are added during the boil. A good rule of thumb can be summed up as 'the more hops that go in early in the boil, the more bitter your beer will be. The more hops that go in towards the end of the boil the hoppier your beer will seem in aroma and flavor though not necessarily in bitterness'
Hop resins are composed of two main acids, alpha acids that are responsible for the bitter flavor in the beer and beta acids that contribute to your beer's aroma. Aroma hops are often added after the wort has cooled and while the beer ferments, a technique known as "dry hopping" which contributes to the hop aroma. Bittering hops are typically boiled for 30–60 minutes and during this time the aromatic compounds evaporate off.
Example: I'll use my latest Weizen/Weissbier recipe below to show how I record my hop additions and how these additions are then used during my brewing process.
I used qBrew's default 'Weizen/Weissbier' style guidelines to crunch this recipe's numbers.
Size 2.13 gallons: Estimated IBU=17, SRM=4, OG=1.050, FG=1.013, ABV=4.9%
2 pounds Muntons Wheat DME
1/2 pound Golden Blossom Honey
1/2 ounce Halleteur pellet hops boiled for 30 minutes
1/4 ounce Halleteur pellet hops boiled for 12 minutes
1/4 ounce Halleteur pellet hops finishing
11.5 gram Fermentis Safbrew WB-06 yeast
Pitched at 65F and fermented at 60F
Directions:
Boil 6 quarts of filtered water
Boil 1/2 oz. hops for 30 minutes
Boil 1/4 oz. hops for 12 minutes
Boil 1/2 lb. Honey for 10 minutes
Add 2 lbs. DME at 5 minutes and boil until hotbreak
Boil DME for 5 minutes
1/4 ounce Halleteur pellet hops finishing
Use Screwy's Cooler to lower wort temperature to 70F
Add 2 quarts cold filtered water to Mr. Beer fermenter
Pour cooled wort into fermenter keg, including 1/4 oz. finishing hops and pitch yeast
Ferment at constant 60F temperature for 21 days
Hops In Muslin Sack Floating At Hotbreak
When I'm designing a recipe I add in all my grains first so I can calculate the alcohol content of the fermentable sugars. The next thing I do is calculate my hop additions to determine how much bittering, flavor and aroma I will want to add to offset the sweetness of the malts and other fermentables in the wort. An authentic German Weissbier style uses Halleteur hops which are relatively low in alpha acids (2.5-5%) so I used 1/2 ounce with a 30 minute boil time to extract the main bitterness level for the style.
If I were only interested in bitterness and using a shorter boil time or using a smaller amount of hops I could have used Columbus hops that have higher levels of alpha acids (13-16%) but I wanted this beer to be as close to the authentic German style as possible.
I use the timings below as general guidelines for adding hops to my recipes.
Aroma: For peak aroma add your hops to the boiling water no more than 7 minutes prior to turning off the heat source.
Flavor: For peak flavor add your hops to the boiling water no more than 20 minutes prior to turning off the heat source.
Bitterness: For peak bitterness add your hops to the boiling water no more than 60 minutes prior to turning off the heat source
The bitterness of beer is measured in International Bittering Units or IBU for short and as a measure of the actual bitterness of a beer as contributed by the alpha acid from hops. Generally speaking, beers with IBUs of less than 20 have little to no apparent hops presence. Beers with IBUs from 20 to 45 are the most common and have mild to pronounced hops presence. Beers with IBUs greater than 45 are heavily hopped and can be quite bitter.
Another factor to be considered is that recipes resulting in a higher OG or Original Gravity will require a higher IBU measurement to maintain 'balance', not too sweet and not too bitter.
An example would be Cowboy Golden Lager w/Pale Export that uses 1 can of Cowboy Golden Lager (HME) and 1 can of Pale Export (UME) as together they will have an OG of 1.010 (4.0% ABV) and an IBU of 16 giving it a 'balanced' flavor.
An example would be Cowboy Golden Lager w/Pale Export that uses 1 can of Cowboy Golden Lager (HME) and 1 can of Pale Export (UME) as together they will have an OG of 1.010 (4.0% ABV) and an IBU of 16 giving it a 'balanced' flavor.
Balanced Beer Hop Chart
Wort OG IBU
------- ---
1.010 4
1.020 8
1.030 12
1.040 16
1.050 24
1.060 32
1.070 40
1.080 48
1.090 56
1.100 64
The BJCP Style Guidelines state the desired number of International Bittering Units (IBU) that are needed to obtain a balance between hopped bitterness and malt sweetness in a hopped beer style. Beers that don't taste sweet or bitter are considered to be balanced, although individual beer drinkers may perceive this differently.
If we were to calculate the bitterness of a 1.21 pound can of Mr. Beer 'Classic American Blonde' hopped malt extract or HME as the only fermentable in the recipe, then we would enter it's alpha acid as 10.2% and using 1 ounce and a 5 minute boil to give us 19 International Bittering Units or IBUs.
When using whole, plugs or pellet hops it's important to point out that the percentages of alpha acids will vary from season to season so make sure you look on the packaging to see what alpha acid values you should enter.



