By Chris Jennings
For the Oregon Beer Growler
Pushing the limits and finding new ways to tackle big problems is what drives many a passionate homebrewer. In the Pacific Northwest, a lot of innovation also revolves around the hop. Brewing huge IPAs can test our equipment and general knowledge about yeast. For instance, once you have that 1.095 starting gravity, getting the yeast to perform can be a challenge. Knowing how to approach common problems when making double IPAs will help you avoid a bad final product and possibly even create a great one.
Brewing Big IPAs
There are a few things to remember when crafting your own version of these big brews. As the name implies, you want to double everything: hops, malts and even yeast. If you’ve never made this style, you can simply start by doubling all of the ingredients in your favorite Northwest IPA recipe. Make sure you have enough grain or malt extract to hit a starting gravity of at least 1.065. Any starting gravity above 1.085 is considered “out of style.” Feel free to experiment. The mash will require a bit more water than normal to ensure a good extraction, so get a boil kettle that’s large enough to handle the extra volume.
When using extract, don’t exceed approximately 10 pounds for a 5-gallon batch. Non-fermentable sugars in the extract will add too much sweetness to the finished product. To make up any extra gravity, there’s no harm in using a small amount of sugar. This technique can also be used if you don’t quite hit the numbers you’re going for when brewing all grain. Add the sugar during the last five minutes of the boil to avoid caramelizing and stir frequently so that it doesn’t sink to the bottom of the pot and scorch. Due to the extra volume, boil for 90 minutes. That also provides 30 more minutes for hop additions. When timing this out, remember that anything incorporated in the first 45 minutes will significantly increase the bitterness of the beer.
Finessing the Yeast
Come yeast-pitching time, be sure you’re using a strain that will be able to tolerate the higher alcohol content you’re shooting for. This information should be available at your local homebrew supply shop. Additionally, it’s advisable to use two packets of yeast. The average yeast pitch has about 100 billion cells. According to yeast companies, this is sufficient for a 5-gallon batch with a starting gravity of 1.050, however, anything below 1.060 should lead to good fermentation.
The biggest problem with brewing higher-gravity beers is the yeast not doing its job. Make sure you help create a wort that’s the perfect, cozy home for those little yeasties to thrive and get to work. After your boil is complete, chill it quickly by using an ice bath or a chiller to avoid the production of dimethyl sulfide (DMS), a common off-flavor that can resemble the taste of cooked vegetables. It’s also important to ensure the yeast is the same temperature as the wort. Too much of a difference will cause the yeast cells to rupture. Take your yeast out of the refrigerator and allow it to warm up to room temperature. Before pitching, introduce oxygen to the wort to help get the yeast started.
Shaking the fermenter is adequate, but if you’re feeling adventurous, you can purchase an oxygenation assembly system that injects oxygen into the wort as it travels into the fermenter. You’ll also need a bottle of oxygen, which can be found at some hardware stores. Take care to not go overboard when adding oxygen.
Even after giving the yeast a fighting chance, it won’t always perform. In the event of stuck fermentation, when the yeast has gone dormant, there are still a few options. Adding more yeast to the fermenter is the quickest and easiest fix. However, the best time to do this would be before the wort has fermented at all because a later introduction could create off-flavors. If fermentation has gotten underway and then come to a halt, transfer the beer from the primary fermenter to a secondary. This will rouse some of the yeast and get the beer away from the dead yeast and protein.
Don’t focus solely on the activity in the air lock because many things can make it bubble. The only way to know whether fermenting has stopped prematurely or finished the way you’d planned is by taking a gravity reading. Even if you didn’t hit the numbers you’d hoped, the test of the tongue is, perhaps, most important. Only you can decided if your method needs adjustment or if you’re on the way to brewing an award-winning double IPA.
Jake's Wedding Imperial IPA [AG]
Jake's Wedding Imperial IPA [Extract]
By Chris Jennings
For the Oregon Beer Growler
The tasty brews we enjoy are, for the most part, created using the same four ingredients: hops, malt, water and yeast. These ingredients all have their own unique flavors and aromas that are most of the time simple to identify. They do, however, lend off flavors and aromas if the beer or wort are not handled properly. The most common undesirable traits are diacetyl, dimethyl sulfide (DMS), oxidation, sourness and skunkiness. These flavors and aromas can be prevented by knowing where in the process they occur and how to avoid allowing them to form. All of the off flavors listed, with the exception of DMS, occur in the final stage of our beer making process.
Identifying Off Flavors and Fixes
Diacetyl is one of the compounds formed by yeast during fermentation. It has a buttered popcorn or butterscotch flavor and aroma. Most often it’s found in beers that have been rushed or lagers that have not been given a chance to rest. If the yeast is given enough time at the right temperature the diacetyl will be reabsorbed. With lagers, a diacetyl rest is used to clean up the flavor of the beer. Once fermentation is close to complete, you want to bring a lager up to ale temperature (65-72 F) to allow the yeast to finish working. This rest occurs naturally with ales as long as they are allowed to finish fermentation without being rushed. A good rule for most ales is to allow them to ferment at least 10 days.
Dimethyl sulfide is a compound that is naturally occurring in the malt that we use to make our homebrews. It can be characterized by the aroma or flavor of creamed corn or cooked vegetables. One of the reasons we boil is to evaporate this compound. When boiling you want the wort to be completely uncovered so that the compounds don’t condensate on a lid and end up right back in the wort. Chilling the wort as fast as possible is also a very important step because the compound is formed between 120-200 F.
Oxidation occurs when the finished beer is exposed to a large amount of air. It will lend to a cardboard or flat flavor and can smell almost like sherry. In older beers, this is sometimes a desirable flavor. In younger brews, however, it means that either the beer was transferred with too much exposure to the air or that it sat too long in the fermenter. Once fermentation is complete, the beer needs to be transferred to an air-tight, sealable container, like a bottle or keg, that carbon dioxide can be added to in order to purge the air. During the transfer, you want to fill the container from the bottom up by using a siphon.
Sometimes a sour beer can be a desirable thing, but when it’s unintended it can be a terrible experience. Sour flavors and aromas can mean that during the brewing process something that touched the wort or beer was not properly sanitized. After the boil is complete, everything that touches our brew needs to be thoroughly sanitized. This will ensure that no wild yeast or bacteria get into our brews, potentially ruining them.
We all have had a skunky beer. Though it has become a common flavor for some brands, it is never a good thing. The skunky flavor is created when ultraviolet light hits the beer or wort once the boil is over. The light breaks down compounds in the hops that then become a skunky flavor rather than the wonderful piney-citrus notes we all love in a good IPA. Make sure that any clear fermentors are covered and hidden from sunlight and use bottles that are not green or clear. These measures will help prevent your homebrews from becoming skunky.
All off flavors are avoidable. As long as we pay attention to the causes, we can ensure that none of our brews end up being dumped down the drain.
Harrumph Session Ale [AG]
Harrumph Session Ale [Extract]
Stories from the print edition of the Oregon Beer Growler.