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