Dried Kelp




About: Tim Anderson is the author of the "Heirloom Technology" column in Make Magazine. He is co-founder of www.zcorp.com, manufacturers of "3D Printer" output devices. His detailed drawings of traditional Pacific...

Here's how to gather and dry kelp.
Kelp is rich in iodine, something many people don't get enough of.
Instead we ingest large quantities of nitrates and perchlorates, which can cause thyroid problems, especially in people with an iodine deficiency. The nitrates mostly come from preservatives in meat. The perchlorates mostly come from solid-fuel rockets and runoff from military installations, and are concentrated in the leaves of irrigated salad crops.
To learn more about these problems, here are some articles from google scholar.

Kelp has a high iodine content. The iodine content varies greatly from one sample to the next.
Excessive iodine can aggravate thyroid problems. Tell your doctor what you're doing and don't over do it.

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Step 1: Gather Kelp

Don't pick living kelp that's still anchored by its stem. The kelp has enough problems already from sea urchins chewing the anchors off, power boaters snagging them and tearing them off, etc etc.
Only gather kelp that's either drifting freely or has washed up on the beach. If there's current, here's how to tell if kelp is anchored without even touching it: If the "head" is pointing upstream, the kelp is anchored. If the "head" is pointing downstream, it's drifting freely.
If you still see a lot of the stem floating at high tide, the kelp is drifting. At low tide you'll see a lot of stem even on anchored kelp.

Here I am off the coast of Northern California. I found this bunch of kelp drifting in the current.
Put it in a bag or other closed container before you get to the beach, you don't want your kelp to get sandy.

Step 2: Rinse the Kelp

If you pick your kelp up off the beach, you'll need to rinse the sand off. The best place to do this is in the sea, right where you gather it. Fresh water makes the kelp really slimy so the sand sticks to it.
It's easier to wash the sand off in salt water than it is in fresh water.
If you want your dried kelp not to be so salty, rinsing in fresh water will do that.
I like mine salty.

Step 3: Dry the Kelp

Drying kelp is easy.
Just hang it anywhere there's some airflow and it will dry out.
You might think of hanging it on a clothesline, but...

Step 4: Built in Clothesline

Kelp has a built in clothesline!
If you find a long piece of kelp, you can just string the whole stem from tree to tree.
The Northwest Coast Natives used to use dried kelp stems as fishing line. If you need to tie two stems together, use a "granny knot". The "granny knot" looks like a square knot done wrong. It's usually a weak and unsafe knot, but is good for tying roots, vines, bark, and other stiff materials that will break if you bend them too far. I learned this from an Ojibway woman while helping to build a birch bark canoe.

Step 5: Dried!

Before long your kelp will be dried. It's amazing how thin and crispy it gets. Even the heads can shrink and turn into something you can bite and chew.
The white stuff on these heads are crystals of salt from the interior.
There are some spots on these leaves, they're eggs from some small sea animal, I eat those too.

Here's my non-scientific method to decide if I need to eat some kelp:
Caffeine stops having much of an affect on me.
I'm getting plenty of sleep, excercise, and sunlight.
I'm getting plenty of iron (anemia runs in my family).
Then I'll nibble a piece of kelp leaf each day for a few days, and usually the caffeine starts working just great!

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    21 Discussions


    Thank you for this and all your very helpful, useful instructables.

    Hope to see you at Maker Faire.



    5 years ago on Introduction

    I have a book on cooking with sea vegetables if you would like to borrow it sometime.


    6 years ago on Step 5

    Good instructable about an overlooked resource! Two cautions - First, I don't believe you need a State of California fishing license to take kelp for personal use, but you DO need a kelp harvesting license if you intend to harvest for sale / profit. Second, there has been detection of radioactive isotopes in California kelp in 2012 following the Fukushima nuclear plant accident. (sorry to be a buzzkill) - Dennis Johnson


    What does kelp taste like? is is crisp and brittle when it dries or chewy/rubbery? I've heard that its very good a while ago when i was in australia, they even had some footage of cattle walking down to the beach to munch on some kelp :)

    2 replies

    It's crisp and brittle when it's fully dried. Salty and tangy if you don't rinse in fresh water. I used to like it best on the second day when it was chewy and no longer slimy.


    Reply 7 years ago on Introduction

    It is a pretty unique flavor, I must say. I cook it in with steamed rice every once in a while- very good!


    10 years ago on Introduction

    how are kelp and seaweed different (he asks, without taking the time to look up the answer himself)? I live in New England, and I think we have the fuzzy reddish stuff that looks like hair, and the green or yellowish stuff in your pics. Are they both kelp, or is the stuff with the bubbly ends kelp and the other seaweed? and are they both edible/tasty? also, I'm getting this downy hair on my chest. should I be concerned??

    1 reply

    Reply 7 years ago on Introduction

    Kelp is a kind of seaweed. The majority of plants in the ocean are kinds of seaweed, so it is just a broad category.

    If it is red and fluffy, it might be dulse, but I'm not sure.


    10 years ago on Step 4

    Wow! I never knew that about granny knots. Any idea why that is?


    10 years ago on Introduction

    Tim you never fail to deliver the goods! Keep 'em coming!


    10 years ago on Introduction

    Excellent. I believe that there are a few small commercial harvesters of wild seaweeds, on both coasts of the U.S., but I'll have to track down the source. I am also fairly sure that "kombu" for making soup/broths is a variety of kelp. I use kombu frequently, in many "brothy" dishes and marinades because it is a natural source of the flavor enhancer MSG. While I agree that synthesized/concentrated MSG is not that great for you, kelp or kombu is a great thing to add that elusive and difficult to describe "other flavor" called "umami".