Gruit

Gruit (alternately grut or gruyt) is a herb mixture used for bittering and flavouring beer, popular before the extensive use of hops. Gruit or grut ale may also refer to the beverage produced using gruit.
Historically, "gruit" is the term used in an area today covered by the Netherlands, Belgium and westernmost Germany. Today however, "gruit" is a colloquial term for any beer seasoned with gruit-like herbs.
Gruit is a combination of herbs, commonly including sweet gale ("Myrica gale"), mugwort ("Artemisia vulgaris"), yarrow ("Achillea millefolium"), ground ivy ("Glechoma hederacea"), horehound ("Marrubium vulgare"), and Calluna heather ("Calluna vulgaris"). Gruit varied somewhat, each gruit producer including different herbs to produce unique flavors and effects. Other adjunct herbs include juniper berries, ginger, caraway seed, aniseed, nutmeg, cinnamon, mint and occasionally hops in variable proportions (although gruit today is often sought out for lacking hops).
Historical context.
The word "gruit" stems from an area now in the Netherlands, Belgium and westernmost Germany. Here, the sale of gruit was a monopoly held by various local authorities, and as such a de facto tax on beer. The word "gruit" could refer to the herb mixture itself or the monopoly of its sale. The earliest reference to gruit dates from the late 10th century, and although largely replaced by hops in the 14th and 15th century, gruit beer was locally produced in Westphalia up to the 17th century.
Outside the area where the gruit monopoly applied, other countries and regions produced ales containing spices, but they were not named gruit. For instance, some traditional types of unhopped beer such as sahti in Finland, which is spiced with juniper berries and twigs, have survived the advent of hops.
In both the area where gruit existed and outside it, the traditional spices were gradually replaced by hops, in a slow sweep across Europe occurring between the 11th century (in the south and east of the Holy Roman Empire) and the late 16th century (Great Britain). In 16th century Britain, a distinction was made between ale, which was unhopped, and beer, brought by Dutch merchants, which was hopped. Currently, however, ale usually refers to beer produced through a top-fermentation process, not unhopped beer.
The main factor for the replacement of spices by hops is that hops were cheaper (especially in the gruit area, where the price of beer flavouring spices was artificially kept high) and were better at rendering the beer keepable. This preservative effect is thought to have had a large impact on the early movement to switch over, although other plants commonly used in gruit mixes, for example sage, rosemary or bog myrtle, also have antiseptic properties likely to extend the shelf life of beer.
Spruce tips as a local food ingredient has a practical aspect as well; it is a plentiful resource in northern latitudes like Alaska, whereas hops must be imported from the lower 48 United States.
Modern brews.
The 1990s microbrewery movement in North America and Europe saw a renewed interest in unhopped beers and several have tried their hand at reviving ales brewed with gruits, or plants that once were used in it. Commercial examples include:
Since 2013, craft brewers with an interest in making gruit ales have banded together to mark February 1 as International Gruit Day. The day is intended to raise awareness of and pay homage to the historical traditions of brewing with botanicals.