Making your own vermouth is easy, but requires a bit of plant knowledge and some forward planning. Here is the basic process that works for me:
1. Select the plants that you wish to use
Any plant you like the smell/taste of (and that isn’t stongly toxic!) is fair game. Some plants work better as a direct infusion into the base medium, others work better in tincture – see my notes. Don’t get hung up on this – often you will have tinctured a glut of something months before, others you may have in dry or fresh form. Those that work well in tincture should be infused in a neutral base spirit, minimum 40% ABV for an appropriate length of time. This can vary widely according to the nature of the material (seeds and roots take longer than leaves or flowers) and the strength of the alcohol being used. Some trial and error and regular tasting is required to ascertain optimum infusion. Fragile matter like flowers and shoots can “burn” and deteriorate to a dull “vegetative” flavour very quickly and may only need an hour or two; roots, seeds and fruits tend to be more forgiving and may take days, weeks or months to reach their best. Don’t fret too much, even over-steeped tinctures can make good vermouth.
Here are just a few wild plants that I recommend playing with. Most are extremely common and i’ve leant toward those that favour The Botanist. I often make complex vermouths with over 50 plants in them, but one with only a handful of well chosen and balanced plants can easily be as good.
(Name – plant – part used – flavour profile – recommended infusion method – health warnings – notes).
– Wormwood (A.absinthium, A.pontica, A.maritima) – leaves – bitter/aromatic – tincture – contains thujone – use dry or fresh
– Mugwort (A.vulgaris) – leaves, seeds – aromatic – tincture or infusion – contains thujone – Use dry or fresh
– Bog Myrtle (Myrica gale) – leaves, flowers, seeds – aromatic/bitter – tincture – Use leaves fresh
– Wood Sage (Teucrium scorodonia) – leaves – aromatic/bitter – tincture – contains thujone – Fresh or dried
– Common hogweed (Heracleum sphondyllium) – green or dry seeds, roots – aromatic/bitter – tincture/syrup – fresh or dry seeds
– Carrot Family (Apiaceae) – see link for my list of a dozen or so common members of this family – all excellent candidates for vermouth
– Wood Avens (Geum urbanum) – root – aromatic – tincture/syrup -preferably fresh roots (can be dried)
– Yarrow (Achillea millefolium) – leaves, flowers – aromatic/bitter – infusion – fresh or dry
– Tansy (Tanacetum vulgare) – leaves, flowers – aromatic/bitter – tincture or infusion – contains thujone – fresh or dry
– Fir/Spruce/Larch – (young) needles – aromatic/sharp – infusion – fresh, pinene content pairs well in gin cocktails
– Sorrel (Rumex acetosa) – leaves – acidic – infusion – add sharpness – infusion – use fresh only
– Fruits such as crab apples, sloes, rhubarb, japanese knotweed, blackcurrants etc can add rounded acidity and fruity depth and work particularly well in sweet vermouths. Gooseberries are excellent in dry vermouths. Tincture or crush & infuse into base.
2. Choose a base medium.
Usually this will be a decent-but-not-too-expensive white grape wine without too much flavour of its own, but non-grape wines can also work. I often use birch sap wine which gives a warm, soft base. Gooseberry wine starts you off from a sharp, fruity platform. Beers and ciders can also work and one bright spark attending our Botanist Academy even skimmed a base for his vermouth from the washback of the Bruichladdich mash tub! By all means break all rules if you think it might work, but generally look for an ABV of 10 – 14% in your base.
3. Infuse Plants Directly into Base Medium
Add your plants for direct infusion to the base. The trick next is to heat the base without losing precious alcohol. Alcohol will start to evaporate rapidly at 78?Celsius (173?Farenheit). If you have the gear, packaging sous vide (under plastic) and heating in a water bath to about 70% for 45-60 minutes is ideal – or if you’re in a hurry give it a blast in the microwave! If you don’t have a vacuum packer/water bath, a carefully watched pan and thermometer work fine. Hold it at 60 – 70?C, lid on, for 30 – 40 minutes. Leave the now partially aromatised base to cool.
4. Fortify with Tinctures
This is the fun bit… Line up all the bitter-aromatic tinctures you have prepared and add them – in a careful and measured way – to the base. If i’m making one bottle, I do this with a tablespoon measure. If you think you might be making a masterpiece, be sure to take note of how much of each tincture you add, though personally I prefer to never make the same vermouth twice, no matter how good the last one was! You are looking to bring the alcohol content up to between 16 and 20% ABV. This probably means about 20 – 30 tablespoons at 40% in 750ml of 14% wine. To be honest, I’ve never measured it accurately, preferring to go by taste. By the end of this process you should have an excitingly bitter fortified wine. If you are a real bitter-lover it can be hard to know when to stop!
5. Sweeten to Taste
A vermouth aromatised with only bitter aromatics will be beyond the enjoyment of all but the bitterest of palates. It will require balancing with sweetness. You can decide where on the dry-to-sweet spectum your vermouth ends up by incrementally and adding your choice of sweetener(s):
– Caramel. This is the traditional method for making sweet vermouths. Heat sugar in a pan with a little water until it starts to caramelise. Its your call how deep and “burnt” you wish to take the caramel to.
– Honey can add complex floral dimensions
– Birch sap syrup is my favorite sweetener for vermouth, offering complex sweet and bitter caramel notes. Its very hard won though, and you might want to keep any bottles made with it for “best” (i.e. yourself!)
– Flavoured syrups. My go-to sweetener for many of my bittersweet concoctions is wood avens (Geum urbanum – aka cloveroot) syrup, which lends a warm, spicy bass note. I’ve had good results with other rich, harmonic flavours like burdock, angelica and hogweed root. Play around.
6. Aging, Clarification and Storage
If you want to really pimp your vermouth, you can age it in oak. This is unlikely to be practical for the scale of production we are talking about here, but it is possible to add oak chips to kilners of your preparation. Once happy with the flavour and balance of your vermouth, strain it thoroughly through several layers of muslin, J-cloths or coffee filter. To achieve a fully clear vermouth its necessary to store it near freezing point (about -8?C) for several days to precipitate any remaining solids. Personally I don’t bother. Once you are happy with the finished products, store chilled and use a vacuum cork to prevent oxidation (especially once you start to get down the bottle).