Gruit Ingredients: Bog Myrtle, Yarrow, Heather and More
Published April 2026 · 8-minute read · by Rich, founder of Unhopped
There's no single 'correct' gruit recipe. Across the centuries when gruit dominated European brewing, the specific herbs varied by region, season, and what grew within reach. But certain herbs appear so consistently across historical sources that they form the recognisable backbone of the gruit tradition. This is a guide to those herbs — what they do, how they taste, and what makes each one distinctive.
For the broader context of how these ingredients fit into brewing history, see our guide to gruit beer and What Is Unhopped Beer? A Complete Guide to Beer Without Hops.
The classic gruit triad
Three herbs appear so consistently across historical sources that they're sometimes called the 'classic gruit triad': bog myrtle, yarrow, and wild rosemary. Most documented medieval gruit recipes feature at least one and often all three.
Bog myrtle (Myrica gale)
Other names
Sweet gale, candleberry, gagel (German), pors (Norwegian).
Where it grows
A wetland shrub native to northern Europe and parts of North America. Found across Scotland, Ireland, Scandinavia, and northern Germany. It thrives in acidic bog and peat habitats.
Flavour profile
Resinous, slightly sweet, somewhere between bay leaf and eucalyptus with a hint of pine. Highly aromatic. The leaves contain essential oils that make them powerful when used in small quantities.
Brewing role
Probably the single most-used gruit ingredient across northern Europe. Contributes both bittering and aromatic character. Has documented antimicrobial properties — its preservative effect is part of why it became so widely used. In Norwegian farmhouse brewing, pors (bog myrtle) remains in occasional use today.
Yarrow (Achillea millefolium)
Other names
Milfoil, nosebleed, devil's nettle.
Where it grows
Common across the British Isles, continental Europe, and much of the temperate northern hemisphere. Grows in meadows, roadsides, and disturbed ground.
Flavour profile
Bitter, slightly camphorous, with herbal and faintly floral notes. Less aromatic than bog myrtle but contributes more obvious bitterness.
Brewing role
Historically used both for flavour and as a preservative. Yarrow has documented antibacterial properties and was widely used in medieval medicine, which made its inclusion in beer doubly appealing — medieval gruits were often as much about perceived health benefits as flavour.
Wild rosemary (Rhododendron tomentosum)
Other names
Marsh Labrador tea, marsh tea, porst (German). Note: not the same as culinary rosemary (Rosmarinus officinalis), which is a Mediterranean herb.
Where it grows
Small evergreen shrub found across northern Europe, Scandinavia, and Siberia. Grows in bogs, peatlands, and boreal forests.
Flavour profile
Resinous, terpene-heavy, with a sharp medicinal character somewhere between camphor, juniper, and herbal eucalyptus.
Brewing role
Widely used in northern European gruits, particularly in Scandinavia and the German-speaking regions. Important modern caveat: wild rosemary contains compounds that can be psychoactive and toxic at high doses. Modern brewers using it do so cautiously and in small amounts. This isn't an herb to experiment with casually.
Other common gruit ingredients
Heather (Calluna vulgaris)
Native to Britain, Ireland, and continental Europe. The flowering tips of heather were widely used in Scotland and northern England — either added directly to the boil or used to line the lauter tun as a natural filter. Heather contributes a honeyed, slightly earthy character. Heather ale (leann fraoich) is one of the surviving unhopped beer traditions, kept alive by Williams Brothers Brewing Co. in Alloa with their Fraoch Heather Ale (continuously produced since 1992).
Juniper (Juniperus communis)
The berries and small twigs of common juniper were used widely across Scandinavia, the Baltic states, and parts of central Europe. Juniper contributes a sharp, aromatic character — gin-adjacent, because gin's defining botanical is the same plant. Juniper is the central flavouring of Finnish sahti and Norwegian farmhouse beers, often used both in the boil and as a filter material in the lauter tun (kuurna in Finnish).
Ground ivy (Glechoma hederacea)
Sometimes called 'alehoof' — an alternative name that reflects how heavily it was used in English ale brewing. Ground ivy is a low-growing herb of the mint family with a slightly bitter, minty character. Common across Britain and continental Europe. Used as both a flavouring and a clarifying agent (the herb causes proteins to settle out of the wort).
Mugwort (Artemisia vulgaris)
A bitter herb related to wormwood. Used widely across Europe, particularly in regions where bog myrtle was less available. Contributes pronounced bitterness and a slightly camphorous, sage-like character. Common in central and eastern European gruits.
Sage, caraway, and aniseed
Garden herbs and spices appear in regional gruit recipes, particularly in central and southern European traditions. Sage contributes savoury, slightly camphorous character; caraway adds bread-and-rye notes; aniseed contributes a distinctive sweet-licorice character. These ingredients are more associated with continental European traditions than British or Scandinavian ones.
Spruce tips, fir tips, and pine
Coniferous tips have been used in beer brewing across Scandinavia and parts of North America for centuries. They contribute fresh, resinous, vitamin-C-bright flavour. Spruce tip beers became particularly important historically as a scurvy preventative for sailors and soldiers in regions where fresh fruit was scarce.
Comparing the herbs
| Herb | Region | Flavour | Modern availability |
|---|---|---|---|
| Bog myrtle | Northern Europe, Scotland | Resinous, bay-eucalyptus | Foragable; sold by herbal suppliers |
| Yarrow | Britain, all of Europe | Bitter, herbal, camphorous | Common; foragable in most of UK |
| Wild rosemary | Scandinavia, Germany | Resinous, sharp, medicinal | Rare; potential toxicity warning |
| Heather | Scotland, N. England | Honeyed, earthy | Foragable; sold dried |
| Juniper | Scandinavia, Baltic, Alps | Sharp, gin-like, aromatic | Widely available (gin-making botanical) |
| Ground ivy | Britain, Europe | Bitter, minty | Foragable; common weed |
| Mugwort | Most of Europe | Bitter, camphorous, sage-like | Foragable; sold by herbal suppliers |
| Spruce tips | Scandinavia, North America | Resinous, fresh, vitamin-bright | Seasonal foraging |
How are gruit ingredients used in brewing?
Gruit herbs are typically added to the boil, in the same way hops would be in modern brewing. Different herbs may be added at different times for different effects:
- Early (start of boil) — for bittering. Yarrow, mugwort, and bog myrtle in larger quantities.
- Mid-boil — for both bittering and aroma. Most botanicals work well here.
- Late (last 5-10 minutes) — for aroma. Bog myrtle, juniper, heather flowers, spruce tips.
Some traditions also use herbs as filter materials in the lauter tun — particularly juniper branches in Finnish sahti and heather in Scottish heather ale. The wort is drained through the branch bed, picking up flavour and aroma in the process.
A note on safety
Most gruit ingredients are safe in moderate brewing quantities. But three caveats matter:
- Wild rosemary contains compounds that can be psychoactive and toxic at high doses. Use cautiously, in small amounts, and only with good information.
- Foraged ingredients require positive identification. Several gruit herbs have toxic look-alikes. If you're foraging, use a reliable identification guide and consider consulting a botanical expert until you're confident.
- Pregnancy — several gruit herbs (mugwort, yarrow, certain others) are contraindicated in pregnancy. Pregnant drinkers should research individual herbs before consuming gruit-style beers.
Where to source gruit ingredients today
If you're a home brewer wanting to experiment with gruit, the main UK options are:
- Foraging — many of these herbs grow wild in the UK. Yarrow, ground ivy, and heather are common; bog myrtle requires more specific habitat.
- Herbal suppliers — UK herbalists like Indigo Herbs, Baldwins, and Neal's Yard stock most gruit ingredients in dried form.
- Home brew suppliers — some specialist home brew shops carry pre-mixed gruit blends, particularly around International Gruit Day.
- Books — Stephen Harrod Buhner's Sacred and Herbal Healing Beers and the Maltose Falcons gruit guide both contain detailed ingredient sourcing notes.
Frequently Asked Questions
What is the most common gruit ingredient?
Bog myrtle (Myrica gale, also called sweet gale) appears most consistently across historical gruit recipes from northern Europe. It contributes a resinous, slightly sweet character and has documented antimicrobial properties that helped preserve the beer.
Is wild rosemary the same as cooking rosemary?
No — they're different plants. Wild rosemary (Rhododendron tomentosum, also called marsh Labrador tea) is a small evergreen shrub of northern European bogs. Culinary rosemary (Rosmarinus officinalis) is a Mediterranean herb. Wild rosemary has psychoactive and potentially toxic compounds; culinary rosemary doesn't. Don't substitute one for the other in brewing.
Can I forage gruit ingredients in the UK?
Yes, several gruit herbs are common UK plants — yarrow, ground ivy, heather, and mugwort all grow widely. Bog myrtle is more habitat-specific (acidic bogs and peatlands, mainly in Scotland and parts of northern England). Always positively identify before harvesting; some gruit herbs have toxic look-alikes. Respect local wildlife and access laws.
Are gruit ingredients safe?
Most are safe in moderate brewing quantities. The main exceptions are wild rosemary (which has psychoactive and toxic compounds at high doses) and several herbs that are contraindicated in pregnancy (including mugwort and yarrow). If you're brewing or drinking gruit beer with unusual ingredients, research the specific herbs first.
Where can I buy gruit ingredients in the UK?
UK herbalists like Indigo Herbs, Baldwins, and Neal's Yard stock most gruit ingredients in dried form. Specialist home brew suppliers sometimes carry pre-mixed gruit blends, particularly around International Gruit Day on February 1st. Foraging is also a viable route for several common gruit herbs (yarrow, ground ivy, heather).
What does gruit beer taste like?
Gruit beer tastes herbal and resinous — less crisply bitter than hopped beer, with aromatic notes from whatever herbs were used. Bog myrtle gives bay-eucalyptus character; juniper gives sharp gin-like notes; heather gives honeyed earthiness; yarrow gives camphor-like bitterness. Specific flavour depends entirely on the herb mix.
- Stephen Harrod Buhner, Sacred and Herbal Healing Beers: The Secrets of Ancient Fermentation (Siris Books, 1998) — the most comprehensive treatment of gruit ingredients available.
- Garrett Oliver (ed.), The Oxford Companion to Beer (Oxford University Press, 2011) — entries on individual herbs and gruit history.
- Susan Verberg, The Rise and Fall of Gruit (Brewery History Society) — historical context on which ingredients were used where.
- Lars Marius Garshol, Historical Brewing Techniques: The Lost Art of Farmhouse Brewing (Brewers Publications, 2020) — surviving Norwegian and Lithuanian uses of these ingredients.
- Maltose Falcons Home Brewing Society — gruit brewing guide with practical sourcing notes.
- Plants For A Future (PFAF) database — botanical and edible-uses information for individual gruit herbs.