There are several other similar, though less widely distributed Osmundea species, referred to generally “flat fern weeds”, including: Royal Fern Weed (O. osmunda), Brittle Fern Weed (O. oederi), and Iridescent Fern Weed (O. truncata). All are edible and delicious in similar ways to pepper dulse, and are most easily distinguished by their habitats (see below).
- Introduction to Seaweed Foraging
- Edible Seaweed Guide
- Seaweed Webinar (includes an in depth film on pepper dulse)
“The webinar was amazing! You are a good storyteller. Scientific information, combined with tips and beautiful picturing. 👏” – Kanlenaki on Instagram
“This was absolutely brilliant, thank you so very much for being so generous with your knowledge! The webinar format of videos and live worked fantastically!” – Sarah Hobbs, Webinar chat comments
- Identification – 3/5 – Quite distinctive when you tune in to it, though novices may confuse it with other small brown seaweeds like caragheen. Look for small (1-8cm) flattened fronds, irregularly branched, though usually roughly pyramidal in outline at the tips. The colour can vary according to where and when it is growing, from yellowish-green (higher up the shore, in summer) to deep chocolate brown (lower down, winter). See notes on closely related flat fern weeds below. The taste of all flat fern weeds is very distinctive and as no seaweeds growing in inshore tidal zones are toxic, this is a good way to confirm that you have one of them. Occasionally people mistake wrack syphon weed (polysiphonia lanosa) for pepper dulse. It shares some of pepper dulse’s truffly properties, but has an unpleasant gritty texture, and is only found attached to other seaweeds (usually tooth wrack). Wrack syphon weed (I call it mermaid’s pubes, though you will occasionally see it more politely listed as sea truffle) has delicious properties once you overcome it’s challenging texture. Dried and powdered it tastes like truffly curried cauliflower.
- Edibility – 5 /5– Pepper dulse is a true gastronomic gem. Surprising, intense, mineral, aromatic, fishy, peppery, garlicy, powerful umami. Variously described as “The Truffle of the Sea”, as a cross between truffle and lobster and (by me!), chef crack. The flavour , while always extraordinary, can be more or less intense according to which Osmundea species you have, exposure and stage of growth.
- Habitat and other flat fern weed species – Clinging to rock from mid tidal range downwards. The different flat fern weeds mentioned above have the following preferences: Pepper dulse – open rock surfaces on mid and lower shore. Royal and brittle fern weed ply their trade somewhat lower, or in non-draining rock pools. Brittle fern weed is epiphytic, usually on wracks. Royal fern weed grows up to 20cm and has a preference for more exposed coast.
- Distribution – 5/5 – Very common in suitable habitats within its tidal range. Best picked, as with most seaweeds, where it is washed by strong currents.
- Season – All year round in exposed locations, but at its best December-May
- How to harvest – trim from the rocks with scissors. DO NOT PULL as this will bring crumbs of rock and barnacle with it, as well as undermining future growth. Don’t clear whole areas – spread your picking around.
- How to eat: Fresh and raw (ideally with the waves crashing at your feet), or dried as a rich, spicy, aromatic seasoning. Fresh pepper dulse deteriorates quickly, keeping in the fridge for a maximum 5 days. Avoid crushing it as this further reduces its fridge life. It can be pickled, but only use cold vinegar, never hot, as this immediately breaks it down and unleashes its volatile compounds into the air. A friend of mine who was experimenting with it poured boiling water over a load. The vapour that came off it he described as “somewhere between raw onions, pepper spray and mustard gas!” (he survived, but was crying and struggled to breathe for a few minutes). Even cold pickled, pepper dulse will become sludgy in a week or two – though it is the best tasting sludge ever. My tastiest ever pickle combined sea lettuce, dried pepper dulse and dried cep – the most umami-rich pickle i’ve ever tasted.
This amazing little seaweed packs an extraordinary flavour that you really have to taste to believe. I’ve fed it fresh to food lovers who reacted with such amazement, delight and determination to have more, that I expect they are now to be found living in coastal caves as ragged pepper dulse junky hermits, venturing out twice a day to gnaw it fresh from the rocks…
One of my very favourite foraging experiences is gathering and eating pepper dulse on the shore, with the waves breaking about my feet. For me, the flavour is deeply elemental – of rock, sea and brimstone. If you inadvertently pull it from the rocks (rather than trimming with scissors as it should be done), it brings with it some of the rock and barnacle to which it clings. I think this close integration with its rock home that gives it its intense minerality. Seaweed forager extraordinaire, Rory “Fresh From The Sea” MacPhee (to whom I am hugely indebted for introducing me to this delight) believes pepper dulse to live in close and complex mutualism with smaller marine algae and shellfish.
More scientifically, much of the flavour may be due to the presence of terpenoids, a class of strong-smelling organic compounds that are also found in conifer resin and many essential oils. These, and the other pungent compounds that give pepper dulse its extraordinary taste are believed to have evolved to deter some aquatic grazing organisms. There is little published research into the nutritional profile of pepper dulse, but my instinct tells me that, while it may contain many of the beneficial minerals and proteins of other seaweeds, it shouldn’t be eaten in large quantities. This is unlikely to be an issue, as the flavour is so intense, you’ll never need much. Unless you become a certified peppy-D junky like me and over-graze it!
It is possible to buy pepper dulse from commercial harvesters and processors in dried form. This is still a magnificent ingredient that can be used in place of salt, pepper and various spices in many savoury dishes. But really, its but a shadow of its fresh self. Having a fridge-life of about 2 days, I doubt you’ll ever be able to buy it fresh. The purest gastronomy is in tasting this seaweed free, among the rock and foam of its elemental home. Why pay infinitely over the odds for less than half the pleasure…?
Apart from just nibbling it fresh, I like to add the fronds to wild sushi and sashimi, or lay them on pieces of smoked egg. Coat the rim of a glass with it in dried, powdered form to make a filthy dirty martini (add a spiral wrack caper instead of a salty olive), or sprinkle it on soft boiled eggs. As a spice, the only limits are your imagination – but as is so often the case with wild foods, keeping it simple often works best – sprinkle it on fish or (even better) shellfish before grilling. See and listen to my exploration of our native spice rack here.
- Edible seaweed guide
- Introduction to foraging for seaweeds
- Recipe: Scottish dashi broth
- Recipe: How to make sushi with wild ingredients
- Wild Food Guide
- 10 wild foods in season now