All About Beer Magazine - Volume 36, Issue 6
January 1, 2016 By
Rosmarinus for Homebrewing Gruit
Rosemary was commonly used to brew gruits in the Middle Ages.

Long before hops were first cultivated for brewing a millennium ago, beers were either unflavored or infused with a mélange of herbs, roots, blossoms and spices. Popular through the Middle Ages in Europe, these botanicals often served the same antiseptic purpose as hops later would, but were also used for their medicinal or healing properties. Many were euphoric, narcotic, psychotropic or even toxic.

According to historian Martyn Cornell, these herbal mixtures were variously known as gruit, grout, grute, kraut, kruit or kruyt, all of which meant “herb” in Continental European languages. Brews made with them are referred to as gruit beer or ale (beer being proper in this context), but often today simply as gruit. In Britain, similarly suffused ales were also common and are more appropriately labeled as “herb ale,” since the term gruit and its derivatives were not used there. I’ll refer to all of them with the catch-all, gruit.

The Botanicals

Increasingly, botanicals are being featured in a new generation of gruit by North American as well as a few Scottish and German brewers. These offer thought-provoking, creative examples for homebrewers to emulate. At our disposal is everything needed to re-create ancient, Medieval and modern interpretations of this intriguing genre of retro-brews.

Gruit can be crafted from many angles. They can be modeled on known anachronistic and ancient recipes or those conjured up by today’s innovative microbrewers. They can be concocted with complex or simplistic formulations. Seasonal, regional or wild gruits are possible with some imagination. They are a perfect and challenging fit for homebrewing gardeners, foragers and herbalists. The list of potential ingredients is extensive.

Yarrow, bog myrtle, and wild rosemary were the most common gruit botanicals during the Middle Ages, according to Cornell. Wormwood, lavender, hyssop, fennel seed, woodruff, heather, mugwort, ground ivy, sage, mint, nettle, lemon balm and juniper berry are also mentioned frequently. All would be apropos in authentic gruit.

Some others that crop up in bygone or current offerings are Labrador tea, St. John’s wort, lemon grass, ginger, rosemary, clove, spruce, caraway seed, anise, nutmeg, cinnamon, licorice, hops, basil, oregano, vanilla, bay leaf, borage, coriander, peppercorns, tarragon, dandelion, goldenrod, rose hips, chamomile, nasturtium, thyme, citrus rind, herbal and true teas, honeysuckle, elderberry and elderberry flowers. There are many other medicinal, wild and common plants that have been used.

All of those can be purchased, grown or foraged.

The Strategy

Since gruit botanicals will used in place of hops in our homebrew, it is necessary to make additions throughout the boil and beyond. Unlike hops, however, their diverse characteristics require that they be considered and treated individually, depending on application. Some can be used as bittering, flavoring and aromatic additions, while others are best for late kettle or “dry” applications to prevent the loss of desired aromatics and flavors.

Bog myrtle, rosemary, yarrow, juniper berry, mugwort, sage and wormwood can be used as bittering agents. Boiling them for about 30 minutes in the wort will result in full extraction. You can make a second or third addition for more flavoring and aromatics as the boil approaches the finish line, much like hops.

Start with 1 to 2 ounces combined weight of these for each addition per 5 gallons.

Most of those listed would not provide much in the way of bittering qualities, but are quite effective for flavor and aromatics. Those should be used for 10 minutes or less in the boil or at knockout. For a more gentle, natural flavor and aroma, they could also be added to the primary fermenter when the bulk of the fermentation has subsided or suspended in the conditioning or secondary vessel. Spices and herbs such as coriander, cinnamon, nutmeg, anise or mint would benefit from a short time in the boil, whereas the more delicate botanicals, like hyssop, heather tips, lavender, or goldenrod should be used at knockout or later to preserve floral qualities. Up to 2 ounces of dried ingredient will suffice.

Consider using a bittering herb for the early additions, and two or three of these flavoring/aromatic ones for the later additions. Don’t discount minimal additions of preservative bittering hops for those that feature floral and herbal aromatics. Don’t want to go all-in with 5 gallons or want to fine-tune the quantities? Brew a pilot gallon of gruit from a gallon of pre-hopped wort and scale up. Use five or fewer different botanicals per batch to prevent an overly “busy” brew.

The Wort

Gruit wort also is worthy of careful, creative planning. For Middle Ages gruit beer, build wort that is somewhat dark and a bit rough around the edges to reasonably imitate its crudely made malt, and include some adjunct.

For all-grain recipes, use a base of premium ale malt or a mix of pilsner/pale and Munich. Add brown or amber malt for a rustic, earthy edge and/or a touch of roasted malt/barley. Oats, wheat and rye were normal grist components, and the creamy mouthfeel and silky texture they offer play nicely with resinous botanicals. Raw flaked and malted grains would all work. Add authentic character and gravity with some wildflower honey. Wort gravity should be medium-strong, say, 1.060-1.080 to avoid overwhelming the botanicals.

Extract and partial-grain brewers can make excellent gruit. Start with pale or amber malt extract and some Munich, wheat or rye malt extract and honey. Steep a small amount of roasted barley. Raw or flaked grains and brown or amber malts need to be mashed, so they are excluded from the steeped grain/extract method. They are, of course, fair game for partial mashers.

For modern interpretations, the wort is as wide open as the botanical additions.

Fermentation

Since the domain of gruit was Northern Europe, Scandinavia and Britain, nearly any top-fermenting European yeast would fit the bill. An altbier or Kölsch yeast ferments quickly and thoroughly, leaves a mellow, malty footprint.

Wheat beer and Belgian yeasts produce unmistakable spicy/fruity notes by themselves and have an Old World, complex character. What about wild or nontraditional microbial strains? Brettanomyces and Lactobacillus were no doubt regular gruit interlopers. A forager gruit with wildflower honey and Brettanomyces primary or secondary fermentation would be an excellent project.

Though gruit is a rather underrepresented beer style, it seems to be gaining some steam.It is a very broad topic and warrants far more exploration butkeep the embers glowing, a coincidental, serendipitous nod to gruit’s ultra-local, small-scale history.  

Alt Kruyt

All-grain, 5 gallons, OG 1.070

Mash at 150 degrees F for one hour: 2 pounds Munich malt, 2 pounds brown malt, 5 pounds Pilsner malt, 2 pounds flaked oats and 1 pound Caramunich III malt

Collect wort, bring to a boil for 30 minutes, then add 1 ounce each of marsh rosemary, bog myrtle and yarrow

Boil for another 30 minutes, stir in 1.5 pounds dark or wildflower honey, chill and transfer to the primary fermenter

Add 1 ounce of each botanical to the fermenter

Ferment with Wyeast 1007 or 2565, or White Labs WLP003 or WLP011

Summer Gruit

Extract/steeped grain, 5 gallons, OG 1.055

Bring brewing water to 155 degrees F and steep 0.5 pounds Carapils malt for 20 minutes

Add 3 pounds wheat DME and 2 pounds light DME and to the brewing water

Bring to a boil for 20 minutes and add 1 ounce Saaz hops

Boil for 20 minutes and add 1 ounce lemon balm and add 1 ounce grated ginger

Boil for 10 minutes, stir in 1 pound light honey, 1 ounce lavender flowers and 2 ounces heather flowers

Turn off the burner and allow the botanicals to steep for 15 minutes with intermittent stirring before chilling wort

Ferment with saison (Wyeast 3711), witbier (White Labs WLP400), Belgian (White Labs WLP570) or German (Wyeast 1007) yeast

For all-grain, substitute 6 pounds Pilsner malt and 3 pounds wheat malt for the DME, and mash at 152 degrees F for one hour


K. Florian Klemp
K. Florian Klemp is an award-winning homebrewer.