Many renowned spirits attach their pedigree to their water source, from Jack Daniel’s using Cave Spring Hollow’s limestone-filtered water to contrasts between whiskeys: Speyside distilleries in the Spey River watershed and the Lakes Distillery distilling the River Derwent having different attributions, while Island Scotch whiskeys have their characters attached to briny air from the surrounding sea. When distillers start tapping into the tastes and aromas of plants that inhabit aquatic habitats, another range of ingredients and connection to place is available. From the salty water of the sea to the fresh water of rivers and lakes to the water-saturated fens, bogs and margins of fresh water, there is an assortment of aquatic and semiaquatic plants that are potential ingredients for distillers.

Cattail moonshine is an American distillation that uses the starchy roots of cattails (Typha species) as the base for creating alcohol. Due to the effort required to collect enough roots, it does not reward distilling spirits on a commercial level. Neither would using American lotus (Nelumbo lutea), another aquatic plant with carbohydrate-rich roots. However, there are aquatic plants whose powerful flavors are required only in small amounts to create distilled products.

Seaweeds have become increasingly used in spirits. Thousands of edible species of seaweed—with tastes ranging through peppery to sweet and contrasting aromas of ozone, fish and truffles—as well as marine plants and algae offer a vast reserve to experiment with. Seaweed harvesting requires knowledge of safe and sustainable harvesting practices and monitoring of environmental factors, which can make it simpler to work with established seaweed collectors. This was one of the reasons I recommended sugar kelp (Laminaria saccharina) as an ingredient for Isle of Harris Gin; in addition to its flavor profile, there was already a local business harvesting seaweed from the area.

Seraphina Erhart, general manager of Maine Coast Sea Vegetables, outlines a few of the variables that must be considered when collecting seaweed for commercial use: “We monitor programs dealing with water quality in the Gulf of Maine, we sample-test our plants, and our organic requirements have stipulations about where we harvest in relation to municipal sewage treatment plants, nuclear power plants and shipping lanes.”

Oregon’s cool oceanic climate, in which rainfall feeds clear streams, is proving ideal for a popular flavor from the other side of the Pacific Ocean—wasabi (Wasabia japonica). When growing wild in Japan, wasabi inhabits clear woodland streams. It is a difficult habitat to re-create, and one of the reasons why areas with climates similar to wasabi’s wild haunts are suited to wasabi growing. Jennifer Bloeser of Frog Eyes Wasabi said, “We found out most wasabi paste is fake [usually made with horseradish, not wasabi]. We were interested in growing something and realized that the Oregon coast had an optimal climate for wasabi and we wanted to be able to provide people with access to the real thing. The water is clean, cool, coastal stream water—wasabi likes cool water—and because of its purity the plants love it! It makes excellent Bloody Marys by infusing the vodka with fresh wasabi root and serving it garnished with wasabi leaves and leaf stems.” The whole wasabi plant is suffused with a fresh hot taste; its leaves are milder than the rhizome—the rootlike stem that is predominantly used for wasabi. While wasabi’s aroma is retained through distillation, the fierce heat is diminished. Paul Bowler, founder of the Winchester Distillery in England, followed the trend for adding wasabi to Bloody Marys and added locally grown wasabi into his still to create wasabi vodka. It has proved a versatile and enduring version of flavored vodka.

When Bowler created Twisted Nose Gin, he looked for an ingredient that was part of Hampshire, England, where his distillery is based. Hampshire is internationally renowned for its chalk streams, whose waters form the perfect habitat for watercress to grow in. Hampshire watercress was once in such demand that a railway line was built to connect the watercress farms with London. It now operates as a heritage rather than a commercial railway, but by using watercress, Paul drew on local history to build his brand as well as adding a peppery note to his gin. Watercress (Nasturium officinale) is not native to the USA, but has become established in 46 states as a noxious weed. Edible invasive weeds are ideal candidates for commercial uses as a means of controlling their spread, particularly in aquatic systems in which chemical control via herbicides is damaging to native wildlife and picking allows removal of the invasive with minimum disruption to native wildlife. If planning to use an invasive species, it is important to check with local authorities regarding what control measures are being used and if there are any stipulations on collection and transport of the plant.

Another aquatic plant with the pepperiness that is mild in watercress and fierce in wasabi is swamp smartweed (Persicaria hydropiperoides, also referred to by the synonym Polygonum hydropiperoides). Its sprawling weedy habit makes it look unremarkable but its leaves have a peppery bite, and it has a history of use in food and medicine in the USA. It is native to most of the states, although it should not be harvested from the wild in Indiana and New York where it is rare.

In contrast, water mints yield a cooling flavor. There are several species of mint that grow in aquatic habitats across the USA. Water mint (Mentha aquatica), one of the botanicals in The Botanist Gin (Bruichladdich Distillery), is not native to the USA but grows in many states. Wild mint (Mentha arvensis) has similar properties and grows across the USA in marshes, fens, lake edges and damp fields. In taste comparisons with spearmint (Mentha spicata), the main type of mint sold as a fresh herb, water mints are more perfumed and slightly less minty in aroma, which makes them combine better with other ingredients than the strong mint note of spearmint.

Sweet flag (Acorus species) grows wild in the USA but has yet to be utilized by contemporary distillers. Acorus calamus is listed by the FDA as a poisonous plant because of its beta-asarone content. However, recent botanical work has distinguished Acorus americanus from Acorus calamus. A distiller who utilizes Acorus americanus and can demonstrate that the end product does not contain beta-asaraone may, in negotiation with the FDA, be able to add this plant to products. For example, Źubrówka vodka reformulated to remove coumarin in order to sell Bison Grass Vodka in the USA. Is sweet flag worth the extra effort on the part of the distiller? Both Acorus americanus and Acorus calamus have been used as flavorings for centuries, and many old recipes for drinks include sweet flag. It is one of the core flavors of Caperatif, a sweet vermouth resurrected by Ade Badenhorst, a vintner based at Kalmoesfontein farm in South Africa. He makes Caperatif using his farm’s eponymous plant—kalmoes is sweet flag in Afrikaans. Sweet flag roots add depth as well as a perfumy note. It is also available in consistent amounts, allowing seasonal variations in other ingredients to be balanced by a signature element.

There is a codicil to using aquatic plants. Water flows across distances and boundaries. Aquatic plants are vulnerable to pollution. One of the reasons that distilleries have to pay due attention to disposal of waste liquids is that excess nutrients or other contamination released in a body of water can spread far beyond the location it is initially put in. On the other hand, wild water and its occupants have shaped so many locations across the USA. Maritime heritage of settlers and Native American coastal communities tapped into edible seaweeds. New York has over 70,000 miles of rivers and over 7,000 lakes and ponds, making aquatic denizens, including edible plants, notable features of the state. The Floridian aquifer that sprawls under south and eastern Georgia, as well as Florida, provides drinking water for over 10 million people: Why shouldn’t its spring habitats furnish ingredients for distilled beverages? For distillers, it is worth looking not only at water sources but also at what grows in them.