In essence, standart Gruit Ale is primarily a combination of three mild to moderatly narcotic herbs:
Yarrow (Achillea millefolium),
Sweet gale (Myrica gale),
Wild rosemary (Ledum palustre).
But for centuries brewers have used more than 64 plants in their beer recipes. Of these:
50 % are aromatic,
38 % are bittering,
53 % are antiseptics,
47 % are medicinal or believed to have magical virtues.
Perhaps what has made Hops so popular with brewers is that it covers all bases, being aromatic, bittering, antiseptic and medicinal. Other than Hops, only four plants would by themselves qualify in fulfilling all 4 functions :
Their origins are essentially European. The Asian plants which arrived in 11th century Europe became widespread by the 16th century, in reduced proportions however. After the 16th century, American plants such as sassafras (aromatic and antiseptic) also made their way into beer recipes.
From my own,
fairly limited experience,
here are some points to remember in composing a good gruit:
Make sure you include a known antiseptic;
Many bitter herbs in leaf form benefit from a change of water to minimize harshness, hence the advisability of making infusions separate from the wort;
You can treat any flavorful bitter the same as hops, adding half at the beginning of the boil, and the other half at the end;
Many of the more delicate flavor-elements are carried off by the carbon dioxide (the other major byproduct of fermentation); hanging some or even most of your herbs in your brewing bucket during primary and/or secondary fermentations, or introducing more herbs at bottling time, are traditional ways of counteracting this effect that I’ve found work quite well;
Some herbs interact with alcohol to produce synergistic effects, such as licorice and calamus–another good reason for “dry-hopping”;
Sometimes less is more (I have a difficult time with this one);
You can make a good gruit with stuff that’s growing right where you live. Though imported spices have been used to flavor ales and meads for centuries, most major gruit herbs were extremely common, local trees, shrubs and weeds. So my feeling is, we Americans should experiment with native plants as much as possible (while not scorning the “green immigrants”). Early European colonists quickly adapted their brewing practices to the local pharmacopoeia, making beer with such natives as sassafras, wintergreen, wild ginger and wild sarsaparilla;
Most herbs are ridiculously easy to grow: they’re perennials, they have very few pests–even the deer leave them alone–and many of them actually prefer stony, infertile ground. This is especially true of the salvias and the artemisias;
Two ounces of any given dried herb is a good average quantity for a 5-gallon batch of beer (but of course there are plenty of exceptions).
If you’ve never brewed, there’s never been a better time to start. With the help of the internet, you can locate cheap supplies and all sorts of exotic ingredients that might’ve taken months to hunt down just a few years ago. If you’re already a homebrewer, congratulations. It’s legions of American homebrewers who, over the last 30 years, have made the microbrew revolution possible.