Sweetgrass is a perennial grass that's native to the cooler regions of the Northern Hemisphere. It grows north of Nebraska from coast to coast, and at higher elevations (above 7,000 feet) farther south in the Rockies. It is not a common grass in the wild; you would have to know what you're looking for to find it. Sweetgrass is also known as vanilla grass, Seneca grass and holy grass. With its sweet, vanilla-like fragrance, sweetgrass has been part of sacred and spiritual practices for centuries. Its scientific name, Hierochloe odorata, comes from the Greek "hieros" (sacred) and "chloe" (grass). More recently, sweetgrass has been classified as Hierochloe hirta.
Sweetgrass prefers cool, moist places along streams, bogs, wetlands or wooded areas. It is not typically found in uniform patches in the wild, but interspersed among other plants. Sweetgrass spreads rather well by rhizomes and is usually propagated from cuttings rather than by seed. (Rhizomes are underground shoots; they grow horizontally through the soil a short distance from the parent plant before sprouting up to the soil surface to begin growing as another plant.) Due to its alpine heritage, sweetgrass often flowers early in the spring, before most other grasses. The longest leaves that grow from shoots without seedheads are preferred for braiding, and also seem to have the most aromatic properties.
Sweetgrass has a long history of use by humans. Early Europeans would spread dried sweetgrass at the entrance to churches on special occasions. Native cultures in North America have many uses for sweetgrass. They burn it as ceremonial incense, weave it into baskets and decorations, and steep it in water for a hair, skin and eye wash, or for use as a cold medicine, analgesic or insecticide. The sweet fragrance of dried sweetgrass is due to a substance called coumarin, which has anti-coagulant properties in the blood. Coumarin is an active ingredient in Coumadin, a prescription drug used to prevent blood clots in some patients after surgery.
Meanwhile, back at the brewery
During a decade of homebrewing experience I have made several batches of pale ale that required dry hopping in the secondary fermenter. I decided to use the same technique with sweetgrass to preserve the delicate aroma that would have been lost if I had added the foliage to the boil. So after the usual brewing process and primary fermentation, I racked a Kölsch-style ale into a secondary carboy, cut an ounce of dried sweetgrass into four-inch pieces and dropped them into the brew.
I must admit that the sight of a bunch of chopped-up grass floating around in my carefully brewed ale made me a little nervous. I wondered if I'd get the delicate vanilla flavor I sought or a batch of contaminated beer that tasted like hay. Things went smoothly, however, and I sampled the brew every day to see how the flavor developed. After five days the flavor seemed about right, so I racked, primed and bottled my experiment and left it to condition in a cool, dark corner of the basement.
After several weeks of conditioning, I chilled a few bottles of my Sweetgrass Ale and sampled the results. The beer had a very distinctive sweet-vanilla flavor and aroma with a slightly grassy finish. But after two months in the bottle, the grassy taste receded, leaving a unique, refreshing aroma and palate with a light, malty finish. Obviously the base beer you choose for your Sweetgrass Ale will influence the final product. I prefer a German-style ale or wheat beer with enough bitterness (20–30 IBUs) to offset the sweetgrass.
If you have trouble finding sweetgrass growing wild in your region, find a local expert to help you track some down or search the Internet for suppliers of dried sweetgrass braids (we list a few sources below). For additional information on sweetgrass, check out the U.S. Department of Agriculture database at http://plants.usda.gov.
(5 gallons/19 liters, all grain)
OG = 1.040 FG = 1.010
IBUs = 13 ABV = 3.9%
5 lbs. (2.25 kg) pale malt
2.5 lbs. (1.12 kg) wheat malt
8 oz. (224 g) crystal malt (10 °L)
8 oz. (224 g) Vienna malt
2.8 AAU Cascade hops (0.56 oz./16 g @ 5% alpha acid)
2 AAU Hallertau hops (0.5 oz./14 g @ 4% alpha acid)
1 oz. (28 g) dried sweetgrass leaves ("dry hop" in secondary)
0.25 oz. (7 g) Hallertau hops (dry hop in secondary)
Wyeast 1007 (German Ale) yeast
8 oz. (224 g) of dry malt extract for priming
Step by step
Crush malt and mash at 153 °F (67 °C) for 90 minutes at pH 5.3. Sparge with a little less than 3 gallons (11.4 liters) of 168 °F (76 °C) water at pH 6.2. Top up to at least 6 gallons (22.8 liters) to allow 1-gallon (3.8-liter) loss during boil. Bring to a boil and add Cascade hops for last 60 minutes of the boil. Add 0.5 ounce (14 gram) Hallertau hops for last 20 minutes of the boil.
When done boiling, chill with wort chiller to 65–70 °F (18–21 °C) and siphon into glass carboy. Aerate the wort and pitch a one-pint (470 mL) yeast starter. Set carboy in 58 °F place (14 °C) until primary fermentation is complete (about 2 weeks). Rack beer onto sweetgrass cut into 3-4 inch pieces and 0.25 ounce (7 g) of whole Hallertau hops in a sanitized glass carboy for secondary fermentation at 58 °F (14 °C). Allow sweetgrass and hops to soak for 3 days in secondary fermenter, then rack into a bottling bucket and add 8 ounces (224 g) of dry malt extract, pre-boiled in a pint (470 mL) of water. Bottle the batch. Allow beer to condition in the bottle for at least one month in a cool, dark place.
Partial-mash option: Replace the 7.5 pounds (3.4 kg) of pale malt and wheat malt with 6 pounds (2.7 kg) of liquid malt extract (LME) for wheat beers. Steep Vienna and crystal malts at 153 °F (67 °C) for 45 minutes. Bring this wort to a boil and add LME.