Continuous Hopping: Experimenting with Hops at Home

In 2001, Dogfish Head released the “90 minute”  IPA, and ever since, people have been trying to figure out exactly what Dogfish Head meant by “continuously hopping” a beer.  On the renown of this nearly perfect IPA, Dogfish Head rose to prominence as one of America’s greatest breweries.  While they had already created several incredible concoctions (like the India Brown Ale, Immort-Ale, and World Wide Stout), 90 minute became Dogfish’s most important contribution to the beer world.  Esquire magazine even called it, “the best IPA in America”(1).  In fact, beer enthusiasts loved 90 minute so much, that the brewery decided to create an entire line of continuously hopped IPAs around the beer which now include a 60 minute, a 120 minute (previously reviewed), and a 75 minute variety (“a cask-conditioned blend of 60 and 90 minute”, with a little maple syrup added into the mix).   However, while thousands have enjoyed the complicated tastes of one of these excellent American IPAs, many people are still wondering what continuous hopping means and how it changes the taste of the beer.  If you or anyone you know has ever pondered these questions, here’s your chance to find out.  Let’s start with hops.

According to Charlie Papazian, beer expert and home-brewing guru, “brewers first used hops in making beer over a thousand years ago”.  In those days, hops were primarily used as preservatives and antiseptics, but by the mid 19th-century, brewers were utilizing hops for their astounding aromas and tastes (2)*.  Hops are flowers, and brewed into beer much like tea is steeped in water. The lupilin glands in each hop contain resins and oils that aid in the brewing process, and create the hops’ bitter tastes.  Brewers add hops to the mix (or wort) at varying points in the process to aid in the “bitterness, flavor, and aroma” of the beer.  Brewers around the world have come up with a simple way of describing how bitter a brew is as a result of the alpha hops used.  They call this standard International Bitterness Units, or IBUs.  “One IBU is equal to 1 millogram of isomerized alpha acid (the resin that makes hops bitter) in 1 liter of…beer.”

So, why is all this information important?  Well, in traditional brewing, hops are added at the beginning of the boil for bitterness, later in the process “for flavoring”, and at the end of brewing, for aroma (3).  However, Dogfish Head had the bright idea of “continuously” adding hops to the beer throughout the entire process of brewing.  They named the beers they created by the time spent continuously hopping each of the brews (60 minute, 90 minute, etc.)  In order to standardize the amount of hops, they had to create a machine, which they called “Sir Hops-A-Lot”. The beers they created were revolutionary in style and precision.  They even have perfect IBUs. 60 minute has 60 IBUs.  90 minute has 90.  I bet you can guess how many 120 has.  Many people have tried continuous hopping at home.   Several people have blogged about attempts at using a stop watch to add hops on a fixed cycle.  I have a friend who has tried dropping in hops at different points in the boil, sometimes with a stop watch and sometimes on whim.  The results differ based on how much, how often, and when you decide to add your hops.  One man, Paul Zocco, went so far as to design his own “continous hopping” device to help standardize his results.  He called his machine, “The Zopinator”.  You can read about it here. However, no home brewer (to my knowledge) has been able to replicate Dogfish Head’s accuracy and precision in making continously hopped beers.

While nobody may be able to duplicate what Dogfish-head has created, you too can experiment with continuous hopping.  You can try simulating Dogfish’s process, making a hopper using Zocco’s method, or creating your own novel way of adding hops. The hops Dogfish Head  uses are “warrior”, “amarillo”, and a “mystery hop X”.  Some people have guessed simcoe, but with so many hops on the market, it’s hard to know.  Mess around with the recipe a little, and you might discover your own 90 minute is better than Dogfish’s.  Either way, play around with hops! Experiment, have fun, and no matter how you go about it:

“Relax. Don’t worry. Have a Homebrew!”

-Charlie Papazian

*Relatively recently brewers have also learned that hops “coagulate and eliminate undesirable malt proteins in the brew kettle”.

1.  Dogfish Head. Shaun Tyndall. 1995. Dogfish Head. 7/11/12 <;.

2. Papazian, Charlie. The Complete Joy of Homebrewing. New York: HarperCollins Publishers Inc., 2003.

3. Paul Zocco, The Zopinator Zocco, Paul. “Zopinator.” Dogfish Head.  Shaun Tyndall. 1995. Dogfish Head.  7/15/12 <;.


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