Bladderwrack, raw (organic?)

Bladderwrack ( Fucus vesiculosus) is a brown algae that can be used raw, preferably in organic quality, to make salads or smoothies. Processed into powder or flakes, it flavors soups and stews.

Use in the kitchen

The most striking feature of bladderwrack ( Fucus vesiculosus) are the eponymous gas bubbles that give the brown algae buoyancy in the water. ¹

Is bladderwrack edible? The edible algae has a salty, sea-like taste with an umami aroma. Freshly harvested bladderwrack is leathery. It is mainly sold dried - cut into strips, as flakes or powder. Whether the dried products are raw food depends on the drying process used and the processing. For raw food quality, the maximum temperature during drying must not exceed 42 °C.

How can you eat bladderwrack? Before use, dried bladderwrack that has been cut into strips should be rinsed and soaked in water for 15-20 minutes - this will give it back its crunchy consistency (and increase its volume). Bladderwrack can then be prepared raw, but it can also be boiled, grilled or baked. Like other algae, bladderwrack can be added raw to a salad or made into a smoothie (e.g. with oat drink, banana andraspberries). Steamed with vegetables, it makes a good vegetable side dish. It also tastes excellent in stews, soups and sauces and, fried, goes wonderfully in vegan pasta and rice dishes. Bladderwrack can also be used to enhance recipes with potatoes. Bladderwrack goes particularly well with chili, ginger or sesame seeds.

Bladderwrack flakes or powder can be used to season all kinds of dishes and stir them into dressings, soups or dips - all you need is tiny amounts. The flakes or powder also liven up bread dough and vegan desserts (e.g. with dark chocolate). The flakes (or the cut pieces) can also be used to make tea, which can be sweetened with a little agave syrup if necessary.

What follows is a delicious, vegan bladderwrack recipe that might be especially interesting for (vegan) clam chowder lovers.

Vegan recipe for bladderwrack soup with oyster mushrooms

Ingredients (for 2 people): 6 oyster mushrooms, 2 potatoes, 1 onion, 20 g margarine, 200 ml oat drink, 100 ml oat cream, 400 ml vegetable stock, ½ teaspoon bladderwrack powder (preferably raw and organic).

Preparation: Clean the oyster mushrooms and cut into pieces. Peel the potatoes and cut into small cubes. Peel the onion and dice finely. Heat the margarine in a pan and sauté the onion cubes for 3 minutes. Add the mushrooms and fry for a further 5 minutes. Add the vegetable stock together with the bladderwrack powder and bring to the boil. Add the potatoes and simmer covered for approx. 10 minutes. As soon as the potatoes are soft, add the oat milk and oat cream and stir well. The consistency should be creamy. Bring to the boil again and simmer on a low heat for 15 minutes. The vegan soup with oyster mushrooms and bladderwrack is reminiscent of a mussel soup. Toast or salad goes perfectly with it.

Vegan recipes with bladderwrack (raw) can be found under the note: " Recipes that have the most of this ingredient ".

Purchasing - Storage

Bladderwrack is rarely available to buy fresh. It can be found dried, cut into strips, as flakes or powder in online shops, including in organic quality. Supermarkets (e.g. Coop, Migros, Denner, Volg, Spar, Aldi, Lidl, Rewe, Edeka, Hofer, Billa) and organic supermarkets (e.g. Denn's Biomarkt, Alnatura) generally do not sell the algae. Bladderwrack can also be found as a dietary supplement in the form of capsules.

The availability of bladderwrack varies depending on the size of the store, catchment area, etc. Our recorded food prices for the DA-CH countries can be found above under the ingredient image - and by clicking on them you can see their development at various suppliers.

Storage tips

Dried bladderwrack can be kept for several months if stored in a dry, cool place protected from light.

Ingredients - Nutritional values - Calories

The energy content of bladderwrack (raw) is 43 kcal and is therefore low. With 0.56 g/100g fat, the algae is also low in fat. Carbohydrates are 9.6 g/100g and proteins 1.7 g/100g. The salt content is relatively high at 592 mg/100g (24.7% of the daily requirement). Raw wakame (2215 mg/100g), nori leaves (3439 mg/100g) and dried kombu seaweed (7112 m/100g) contain even more (and too much) salt. ²

Fresh bladderwrack contains a lot of iodine, at 27,600 µg/100g. ³ Algae generally contain a lot of iodine. For example, dried dulse contains 7,500 µg/100g, raw arame algae 8,750 µg/100g, raw laminaria algae 38,000 µg/100g and dried kombu algae 295,400 µg/100g. ² The iodine content of algae can vary considerably depending on the region where it is grown, how it is stored and how it is processed. Read more about iodine in the chapter "Danger - Intolerances - Side Effects".

Raw bladderwrack has a high folate content (180 µg/100g; 90% of the daily requirement). This content is similar to that of arame seaweed (180 µg/100g), kelp (180 µg/100g) and kelp (182 µg/100g). Raw wakame has slightly more at 196 µg/100g and dried dulse has about seven times as much of the vitamin at 1269 µg/100g. ²

Vitamin K is also present in a considerable amount at around 66 µg/100g (88% of the daily requirement). Arame algae (66 µg/100g) and Laminaria algae (66 µg/100g) contain a similar amount. Swiss chard contains much more vitamin K (830 µg/100g). ²

The complete ingredients of bladderwrack (raw), the coverage of the daily requirement and comparison values with other ingredients can be found in our nutrient tables. In the article Nutrients explained you will get a detailed insight into the topic.

Health effects

Bladderwrack ( Fucus vesiculosus) is rich in health-promoting compounds such as polysaccharides (such as fucoidan and alginic acid), polyphenols (such as phlorotannin), xanthophylls (such as fucoxanthin), β-carotene and essential minerals (such as iodine). ^{1, 4} The amount of biologically active compounds in seaweed varies depending on geographical origin, reproductive phase, environmental stressors and season of collection. ⁴

Fucoidans are sulfated polysaccharides belonging to the fucan family and are considered bioactive compounds found only in brown seaweed. Various pharmacological activities have been described for fucoidans ^, including antioxidant, anti-obesity, antidiabetic, antimicrobial, antiviral, antitumor, anti-coagulant and anti-inflammatory.4,5 Phlorotannins are a group of polyphenolic compounds also found only in brown seaweed. They exhibit numerous biological activities such as antioxidant, antibacterial, anti-inflammatory, antidiabetic, anticarcinogenic and antitumor properties.4,6,7 In addition ^, brown seaweed, which has a high concentration of phlorotannins, has been reported ^to have anti-HIV activity.8 Results from a 2008 study showed that fucan purified from bladderwrack also has antiviral effects and high inhibitory activity on HIV reverse transcriptase. ⁹

A 2022 study investigated the antihyperlipidemic (lipid-lowering) effects of phlorotannins from bladderwrack on rats. The results showed that phlorotannin-rich extracts can improve lipid profiles of rats with induced hyperlipidemia (lipid metabolism disorder with elevated blood fats/lipids). Therefore, phlorotannin-rich extracts from bladderwrack could help treat hyperlipidemia, insulin resistance, liver steatosis and associated inflammation. ⁷ Another study from 2020 analyzed the effect of bladderwrack on fat deposition in the liver after administration of a high-fat diet to rats. In summary, the seaweed extract effectively reduces body weight and postprandial (after eating) blood sugar levels, making it a useful tool for reducing the risk of metabolic diseases associated with the consumption of large amounts of dietary fat. ¹⁰

Is bladderwrack suitable for weight loss? There are articles about the slimming effects of bladderwrack on people with blood group 0. However, we are not aware of any scientific studies.

Dangers - Intolerances - Side effects

The brown algae bladderwrack and algae in general are a source of the essential trace element iodine. This plays an important role in thyroid function, as it is required for the synthesis of thyroid hormones. However, long-term, high intake of iodine is problematic and can lead to thyroid dysfunctions such as hyperthyroidism or hypothyroidism.

The recommended iodine intake is 150 μg/day for adults. The Scientific Committee on Food ( SCF) has set a maximum tolerable amount of 600 μg/day. The amount of brown algae biomass that corresponds to a certain amount of iodine varies considerably. The maximum daily iodine intake for adults (600 μg) can be achieved by consuming 0.2 to 11 g of processed, dry brown algae. ¹¹ Although 1 g of bladderwrack, which contains 276 μg of iodine- ³, exceeds the recommended daily intake, it is still within safe limits. Therefore, only consume bladderwrack in small quantities and, when purchasing algae products, make sure that the iodine content and a maximum recommended daily intake are stated. This will enable you to estimate how high your iodine intake is and avoid over-consuming. People with a thyroid dysfunction should avoid consuming bladderwrack.

Although processing processes such as warm water treatments, cooking and fermentation can significantly reduce the iodine content of brown seaweed, it is still high afterwards. ¹¹ A 2023 study examined the effect of warm water treatments in freshwater and seawater on the levels of iodine and other nutrients in the brown seaweed sugar kelp ( Saccharina latissima). The results showed that treatments in both freshwater and seawater significantly reduced iodine content. However, treatment with freshwater resulted in a greater loss of soluble nutrients, mainly carbohydrates and minerals, while treatment with seawater appeared to result in greater nutrient retention. Despite the loss of iodine during processing, the final levels found in this study were higher than current recommendations. ¹²

Folk Medicine - Natural Medicine

The jelly-like mucus contained in the vesicles of bladderwrack has been a liniment for centuries in coastal regions of Great Britain to treat rheumatism, bruised limbs and sprains. Bladderwrack was also used in the fishing villages of Yorkshire as a remedy for bow legs in small children. In coastal counties of Ireland the liniment was used for "weak", sore or sweaty feet and swollen legs. A lesser-known practice, which has been handed down from Donegal, was to suck the mucus from the vesicles and swallow it to cure a sore throat. ¹³

Ecological footprint - animal welfare

Algae remove CO₂ from the atmosphere, which is good for the climate. According to researchers at the Max Planck Institute for Marine Microbiology in Bremen, brown algae absorb large amounts of carbon dioxide from the air and release some of the carbon it contains back into the environment in the form of mucus. Since the algae mucus, called fucoidan, is difficult for other marine creatures to break down, the carbon remains bound in it and does not return to the atmosphere for a long time. Researchers estimate that brown algae could thus absorb up to 550 million tons of carbon dioxide from the air every year. ¹⁴

An LCA calculation of agar (vegan gelling agent made from red algae) came to a CO₂ footprint of -1.11 kg CO2eq/kg from raw material extraction to leaving the factory gate ('cradle to gate'). The cultivation of seaweed had a negative CO₂ life cycle assessment of -7.21 kg CO ₂ eq/kg. This result shows that the carbon uptake by macroalgae can offset the carbon emissions from production. ²¹ This makes macroalgae an excellent starting product. It should be noted, however, that seaweed as a food can only store CO₂ for a short time. ²³ Apart from the very good CO₂ balance, the cultivation of macroalgae also offers many other so-called ecosystem services: it is good for marine life, reduces eutrophication (too many nutrients in the sea) and reduces ocean acidification. ²² But of course it all depends on the implementation and we must be careful not to make the same mistakes in farming at sea as we do on land. Organic seafood should be preferred, as is the case with land-based products.

The production of 500 million tons of algae could absorb 135 million tons of carbon, which corresponds to about 3.2% of the carbon added to seawater annually through greenhouse gas emissions. ²⁰ Further studies and experiments are needed to determine the effect, and in particular in what form the CO₂ can be stored in the algae in the long term.

Seaweed farming can produce large amounts of nutrient-rich food for human consumption. In addition, marine farming appears to be more sustainable than land-based farming, as seaweed farming does not require fresh water ( water footprint), chemical fertilizers, or land, which are major negative factors of farming. ¹²

Animal protection - species protection

Bladderwrack provides a habitat for many marine creatures such as fish, mussels, amphipods, crabs and snails. ¹⁵

In many coastal areas of the world, a shift from perennial benthic vegetation to ephemeral (annual) macroalgae is observed. In the Baltic Sea, this has led to a decline in the previously dominant Fucus species (including bladder wrack). Among other reasons such as increased sedimentation, loss of suitable habitats due to commercial stone extraction or increased grazing by small invertebrate herbivores (as a result of overfishing of the predators of these herbivores), nutrient enrichment appears to be the main reason for this change. A significant decline in Fucus is likely to affect large parts of the ecosystem, as algae provide food for numerous herbivores, substrate for epibionts and shelter for many associated species, play an important role in biogeochemical cycles and provide other valuable ecosystem services. ^{1, 16}

Worldwide occurrence - cultivation

Bladder wrack ( Fucus vesiculosus) is a widespread species that occurs naturally on the coasts of the North Sea (including the Irish Sea), Baltic Sea (including the Gulf of Bothnia), Arctic Sea, Atlantic and Pacific Oceans. ^6,13,17

Found in the wild

Bladder wrack can be found on the shallow coasts of the North Atlantic, the North Sea and the Baltic Sea. It also inhabits the middle tidal zone and river mouths. The algae grow on rocks, stones and wood. They tolerate high temperatures and low salinity. ^1.18

Cultivation - Harvest

Bladder wrack is mainly harvested from wild stocks. Due to its difficulty in artificially inducing reproduction (it has no mobile reproductive stages), it is not currently cultivated. However, attempts are being made to establish bladder wrack on artificial substrates. ¹

Algae can not only be cultivated according to organic standards, but can also be collected. When doing so, it is important to ensure that the collection waters are clean. Collected organic algae therefore come from waters far from busy ports, sewage discharges, nuclear power plants, conventional aqua farms or other sources of pollution. It is also important to harvest sustainably, i.e. only take as much as can grow back. Stocks must be maintained so that other marine life is not harmed by the harvest. ¹⁹

Further information

The brown algae bladderwrack ( Fucus vesiculosus) belongs to the Fucaceae family. It is a perennial algae, around 10-30 cm long, with a brown-green, flattened thallus (vegetative body) that is forked in one plane. An adhesive plate anchors the brown algae to a solid substrate (such as stones, wooden posts, mussel shells). The gas bubbles give the plant its name and are characteristic. They are arranged on both sides of the midrib and stand in pairs in the forks. They ensure that bladderwrack is buoyant in the water. To prevent the plant from drying out at low tide, it is covered with a layer of mucus. ¹

Also read our articles on other brown seaweeds such as arame, wakame, kombu seaweed (dried) and laminaria seaweed ( Laminari a spp.) and on red seaweeds (kelp) such as cartilaginous kelp, dulse (dry kelp) and nori sheets.

Alternative names

Bladderwrack is also called sea oak, sea oak, blahewrack, humpweed, pigweed, Klever, stoneklever or kelp.

In English it is called bladder wrack, lady wrack, sea-wrack, button seaweed or bubbling wrack. ¹³

Other uses

In addition to its use as a food or medicinal product, bladder wrack is used to produce natural antioxidants and bio-oil and to make cosmetics. It is also being investigated as a potential biosorbent for the absorption of toxic metals from contaminated wastewater. ¹⁷