Gruit (or sometimes grut) is an old-fashioned herb mixture used for bittering and flavoring beer, popular before the extensive use of hops. Gruit or grut ale may also refer to the beverage produced using gruit. Gruit was a combination of herbs, traditionally consisting of...
sweet gale (Myrica gale), mugwort (Artemisia vulgaris), yarrow (Achillea millefolium), heather (Calluna vulgaris) and Labrador Tea (Rhododendron tomentosum, formerly known as Ledum palustre). Gruit varied somewhat, each gruit producer including different herbs to produce unique flavors and effects. Other adjunct herbs included juniper berries, ginger, caraway seed, aniseed, nutmeg, cinnamon, and even hops in variable proportions. Some gruit ingredients are now known to have preservative qualities. [wikipedia]. Besides the traditional gruit herb mixtures, other herbs have a history of use in ales. Costmary (Tanacetum balsamita), also known as bible leaf or alecost, was once used to flavor ales, as the name alecost implies. Chamomile makes a lovely ale. The list goes on and on. The book Sacred and Herbal Healing Beers contains recipes for a number different herbs. Another resource with some info on gruit-based beers is Richard Unger's Beer in the Middle Ages and Rennaissance.
How to Make Gruit
Making gruit is as easy as brewing beer at home. Think of Gruit as a hop-free herbal ale; instead of using hops for bittering and aroma, you'll use other herbs. For the best aroma, you should try to use fresh or day-old herbs. This way, the volatile aromatic oils have not evaporated yet. Add bittering herbs early in your boil, and you aromatic components at the end, just like you do with hops. One of the challenges in using new herbs is how much to use. For a point of reference, look at recipies online, or check out a good book on the topic. You can convert any recipe to some standard units, such as oz herb per gallon wort. I list good concentrations for some common brewing herbs below.
The easiest way to brew a tasty batch of hop-free herbal ale or gruit is to start with a good recipe. We are adding new herbal ale recipes all the time, so check back often.
Herb Ratios for Herbal Beers
Here are some ballpark numbers for how many ounces of each herb are needed to flavor one gallon of medium gravity (~5% ABV) ale. Unless otherwise noted, weights are for partially dried herbs. Herbs get lighter as water evaporates. If have very fresh cuttings, use more (add 50% or double weight). If your herbs are very dry, use less (say 1/2 or 2/3 the amount I list here). Ounces of semi-fresh herbs for each gallon of ale.