Rachel Lambert: forager, author, guide
Foraging colourful seaweeds on a foraging course in Cornwall

Hi, I live two minutes from the sea and a stone's throw from Seasalt's first-ever shop! I run my own business teaching people to forage along the coast and seashore in Cornwall. Though the coastline is also where I chill out, look for finds and walk the dog...

This is a blog I wrote for Seasalt Cornwall where I discuss things I find when beachcombing along the shoreline, including;

  • a colourful range of seaweeds
  • kelp claws, 'brains' and whips!
  • litter picking
  • sifting for micro plastics (and taking them off the beach)
  • sea glass, a range of shells including limpet 'rings' and finding a special pebble.

You can read the full blog here; A walk along the seashore with Rachel Lambert

Bladder wrack or popweed (Fucus vesiculosus) - the seaweed of my childhood - is a common, edible seaweed with air bladders that can be popped like bubble wrap! It also has amazing health benefits including the ability to inhibit a common gut bacteria.

Here I share where to find it, how to identify it, common mistakes, health benefits and why it is good for our guts. How to harvest it, how it reproduces and easy and safe ways to incorporate it into your diet.

Bladder wrack is one of 16 seaweeds in my pocket seaweed book, along with two step-by-step recipes for it, and I regularly teach it on my seaweed foraging courses.

Bladder wrack growing on the shore in Scotland

Where to find bladder wrack

Bladder wrack is a common seaweed that grows around the coast of the UK and across the shores of the Atlantic and Baltic seas. It favours sheltered, rocky areas with some degree of disturbance and rough treatment from the sea!

It can also be found in exposed rocky areas, however it may not form the 'bladders' in really exposed places (see how to identify bladder wrack and common mistakes).

Detail of the bladders and mid-rib of bladder wrack

How to identify bladder wrack

Bladder wrack is a brown seaweed and one of several species of 'wracks'. It is a yellowy-brown when wet, but looks almost black when dried. It has pairs of 'bladders' (air-filled pockets) either side of the mid-rib, which usually makes it easy to identify.

It grows from 15 to 90 cm long and from 0.6-2.5 cm wide and has branched fronds often with a wavy edge. The air pockets give it the common name popweed, as you can pop these bladders like a seaweed bubble wrack!

How to harvest bladder wrack

Just cut the fresh tips of the seaweed, leaving plenty behind. Only cut the tips from half of each plant.

Harvesting bladder wrack

Can bladder wrack be confused with other seaweeds?

Yes. Sometimes bladder wrack is confused with similar seaweeds such as flat wrack, spiral wrack (Fucus spiralis) or serrated, toothed wrack (Fucus serratus).

However neither of these seaweeds have air bladders and spiral wrack tends to twist into a subtle spiral as it grows and toothed wrack has a distinctive serrated edge.

Confusion can arise, however, when bladder wrack grows on exposed shores and the bladders don't form, or when it is too young to have produced bladders yet. A wavy or toothed edge is easy to distinguish, but comparing it to spiral wrack, you'll need to check if the fronds twist and check the size.

Spiral wrack only grows to about 20 cm long and 2 cm wide, so less than a quarter of the length that bladder wrack grows.

Handful of fresh bladder wrack tips

Health benefits of eating bladder wrack

Bladder wrack is high in iodine, vitamin C, iron and calcium. Iodine is essential for humans, however the World Health Organisation (WHO) advise on not consuming too much iodine and therefore limiting your intake of brown seaweeds.

In Japan, daily consumption of brown seaweeds, such as kelp in miso soup is common, and the Japanese are renown for their healthy, traditional diet. Kelp (Laminaria digitata) is considerably higher in iodine that bladder wrack.

Bladder wrack and other seaweeds and seagulls

Seaweed Tip...

Thinking of bladder wrack as a condiment rather than a sea vegetable is a helpful guide. However, please consult your GP or a medical herbalist if you have an overactive or underactive thyroid and are taking medication such as thyroxine. As your intake of iodine will effect the thyriod and how this medication works. More information on thyroxine can be found on the NHS website.

Bladder wrack for healthy guts!

Research shows that bladder wrack inhibits the adhesion of a common gut bacteria called Helicobacter pylori to the gut wall. This bacteria is fairly common in humans and regular consumption of bladder wrack can help eliminate it from the body. So the message is; use bladder wrack regularly but in small amounts.

How to use bladder wrack

I have four recipes for bladder wrack in my seaweed foraging book; Pickled Bladder Tips 3 x ways (with cucumber, kohlrabi and along with spices), and a Chicken Broth with noodles and bladder wrack.

However, I use bladder wrack in other ways too! I find it easier to dry and finely grind* bladder wrack and sprinkle small amounts onto fried eggs, into soups, stews, blended with sea salt on fish, into crackers or dips.

Pinch pot of bladder wrack seaweed

When I asked seaweed expert Christine Maggs, one of the co-authors of Seaweeds of Britain and Ireland, how much seaweed should be eaten daily? Her reply was 'no more than a teaspoon.' Actually, one teaspoon of dried and ground seaweed is quite a lot! Personally, I do not eat as much as a teaspoon of seaweed a day, but do manage to add a pinch onto many dishes I make.

*I have guidelines on how to dry and grind seaweeds in my seaweed book.

Seaweed Tip...

Consider having small pinch pots of ground seaweed next to your cooker, or next to your salt and pepper. I find this reminds me to use them regularly!

Pinch pots of dried and ground seaweeds

I teach seaweed foraging courses throughout the year here in Cornwall, UK. I'd love to show you more about these amazing sea vegetables.

Bleached white gutweed (Ulva intestinalis) seaweed

At last, I had arrived on the Isle of Arran. I stepped onto the beach as soon as I could; made a small fire and pottered around perusing the edible wild plants on the foreshore.

After 17 hours of travel on train, bus, ferry and foot I was a little shell-shocked to say the least. Penzance to Arran is a long way, and the public transport journey convoluted. I arrived as I often do - wanting to orientate myself with my new surroundings - and I did feel new, things, the land, felt new.

It was evening, the tide was out and I wasn't sure of the time. June meant that it stayed light till, well, till later than I was used to in Cornwall.

Rowan in flower on the foreshore of Arran Isle

Spotting edible wild plants around me

Rowan, bittercress, nettles, meadowsweet, elder, dock, sea spinach, sea radish... The familiarity of the plants around me, as always, helped me arrive. As I tottered over the seaweed strewn rocks; bladder wrack, channelled wrack, gutweed. Home from home, sort of.

Bleached white seaweed with wrack tips and rock pool on Arran

Which seaweeds are edible?

All of the seaweeds and land plants I mention and spotted are edible and good for you, if processed in the right way. Teaching about the edible seaweeds is a personal passion of mine. Bladder wrack with the bubbles is highest in iodine. Some seaweed is good for helping lose weight and many are low in fat and have high amounts of vitamins and minerals. These seaweeds grow across the UK, but some of the best spots are in Cornwall, Devon, Wales and Scotland.

Each seaweed has an optimum growing and harvesting season and some seaweeds like to grow higher up on the shore, where the environment suits it best. Here I found channelled wrack (Pelvetia canaliculata) and, well, bleached-white gutweed (Ulva intestinalis).

Why does seaweed bleach white?

I looked, I stared. I wasn't sure if I'd ever seen such a large area of bleached, living seaweed before. Of course it was very near mid-summer, with plenty of light and heat, but a sea (excuse the pun) of white seaweed...

Green seaweeds such as gutweed can start to loose its colour when exposed to light. That's why on my seaweed courses and in my seaweed book I suggest storing dried and edible, green seaweeds like gutweed and sea lettuce in a dark cupboard. After all, we eat with our eyes too and green is such a delicious colour to eat!

So, naturally, on that beach on Arran I didn't eat, I stared. My familiar green seaweed wasn't a beautiful edible green colour, it was white, so I left it and walked away.

Handful of freshly picked green seaweed

How seaweeds protect themselves

Seaweeds have various mechanisms to survive change in temperatures and I've written about this before in; Can seaweeds survive the frost and snow?

Gutweed, the white seaweed I was staring at, is particularly good at navigating extreme changes in temperature and salinity. Suited to growing in rock pools on the upper and middle shore it is rather exposed. Sacrificing the top covering to the sun, it can protect the seaweed growing underneath it, where it remains green and in the water.

However, as the heat rises and the water evaporates, higher levels of salt means seaweed can become permanently damaged and significantly reduce its growing and reproducing ability .

Bleached gutweed seaweed growing over rocks in summer

A nature-made seaweed salt

It's now a year (almost to the day) since I was on Arran, and now here I am next to a rock pool of bleached gutweed seaweed on my local West Cornwall shoreline. As my friends swam in the (not-so) warm sea, I pottered around and decided to harvest some.

Wow! To my surprise the dried, white seaweed was crisp with sea salt. Of course! The water had evaporated and what was left was a combination of dried out seaweed and salt.

Seaweed salt is full of nutrients, including iodine, you can buy it or make your own. I have delicious seaweed salt from Scotland and Cornwall, I couldn't say which is best!

Bleached gutweed seaweed and natural sea salt

How to make sea salt and seaweed salt

Sea salt is normally a time-consuming process, whether by companies such as Cornish Sea Salt or artisan wild foodies such as Pascal Baudar. However, here nature had done it, naturally.

Similarly, making a seaweed salt normally requires drying and crumbling seaweeds and combining them with ready-made sea salt. Not here!

This was nature-made, naturally occurring seaweed salt!

Wow! This was such a wild find!

Bleached gutweed seaweed (Ulva intestinalis) protecting lower layers of the same seaweed

How to use nature-made seaweed salt

I plan to cripsy fry some - think ready-salted seaweed snack and crumble some over a homemade sourdough pizza - recipe to come soon.

I'd love to hear if you've ever found this naturally occurring seaweed salt, used it or made your own.

Want to find out more? I cover so much on my 3 hour seaweed foraging course, there's also 5 seaweeds (and recipes in my wild food foraging book and 16 in my seaweed book!

Bowl of shredded, naturally bleached and salty seaweed

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