A common way to make beer using malt extract is to rely on light or pale malt extract as the base of the recipe. To add additional malt color, flavor and aroma, specialty grains are steeped. For example, the grain bill for a pale ale recipe may consist of several pounds of dried malt extract and a pound or so of crystal malt. In a recipe like this, the specialty grains supply their flavors, aromas and a small amount of carbohydrates (that add to the specific gravity of the wort).
The light malt extract base supplies most of the carbohydrates (fermentable or otherwise) to the wort, as well as some flavor and aroma. However, given the way malt extract is processed, much of the aroma associated with the base malt is lost. (For example, Pilsner malt extract (liquid or powder) is made from Pilsner malt (a malted grain). During it’s manufacture, some of the aroma of the Pilsner malt (the grain) is lost while the extract is condensed via evaporation.) If you are formulating an extract beer, there is an easy way to add base malt aroma back to your beer — add some base malt to your steeped malts. Common base malts include 2-row pale malt, 2-row pale ale malt, Pilsner malt, Vienna malt, Munich malt, wheat malt and 6-row pale malt.
Although specialty grains add malt aroma to a beer, the aroma they add is different from the aroma of base grains. You can easily verify this by smelling a handful of 2-row pale malt vs. a handful of crystal malt.
Some extract brewers may be reluctant to add base grains to their steeping grains because they have heard that base grains need to be mashed, not just steeped. Steeping base grains at the wrong temperature or volume can lead to starch haze in your beer. While this is true, mashing is similar to steeping. If you “steep” base grains in the right temperature range and with the right amount of water, you are mashing and do not have to worry about starch haze.
Adding base grains to most extract beers is easy. First decide how much base grains you can steep. This will depend on how much space you have in the vessel you steep in. Adding even 1.0 pound (0.45 kg) of base malt to a 5.0-gallon (19-L) recipe can make a noticeable difference. Two pounds of combined base and specialty malt can be steeped (mashed) in a standard 3-qt. (~3 L) soup pot. The “grain tea” from this can be added to your brewpot when it is ready, and you can be heating water in your brewpot during the steep (mash).
Once you have decided how much base grain to add, calculate how much light malt extract to remove from the recipe to compensate. If you use dried malt extract, multiply the weight of the base malt added by 0.53 and subtract that amount of malt extract from the recipe. If you use liquid malt extract, multiply the weight of the base malts by 0.65.
For example, let’s say your recipe contained 7.0 lbs. (3.2 kg) of dried malt extract and 0.75 lbs. (0.34 kg) of crystal malt. Additionally, lets says the all-grain equivalent recipe specified 12 lbs. (5.4 kg) British 2-row pale ale malt (Maris Otter) and the same amount of crystal malt. You decide to add 1.25 lbs. (0.57 kg) of base malt (the Maris Otter) to make 2.0 lbs. (0.91 kg) of malt total. To make room for the added base malt, subtract 1.25 X 0.53 = 0.66 lbs. of dried malt extract from your initial amount (7.0 lbs). Your grain bill is then 6.33 lbs. (2.9 kg) dried malt extract, 1.25 lbs. (0.57 kg) British 2-row pale ale malt (Maris Otter) and 0.75 lbs. (0.34 kg) crystal malt).
When you brew, just multiply the total weight of your grains (base plus specialty, in pounds) times 1.4 and add this volume of water (in quarts). (Alternately, multiply the weight in kilograms by 2.6 and add this volume of water in liters.) For example, if you have 2.0 lbs. (0.91 kg) of combined grains, “steep” them in 2.0 X 1.4 = 2.8 qts. of water.
“Steep” (mash) the grains at 148–162 °F for around 45 minutes. If you have the equivalent all-grain recipe, steep at the temperature of the saccharification rest (usually the longest rest if there are more than one, and in the temperature range given above).
Adding base grains to an extract beer recipe is simple and will definitely improve the malt aroma of that beer.