1/4 Spirulina 101: The Intro

Klara Zietlow
5 min readNov 28, 2021


This is article 1 of 4 in a series about everything you need to know about spirulina. After this introduction, you’ll learn about different grow and harvest methods, nutrition and applications, and barriers to adoption. Enjoy learning more about green goo than you ever knew you needed to!

You may have heard somewhere on the news or from a health nut friend that everyone will be eating algae in the future. Usually that’s greeted with a less than enthusiastic facial expression.

Well, I’m here to tell you that you should…listen to your friend 🙃 Okay, algae won’t become the next corn or wheat or soy but it will definitely play a huge role in transforming our diets from unhealthy + unsustainable to nutritious and earth friendly.

And it all starts with spirulina.

What is Spirulina?

These tiny things are what all the hype is about

The granddaddy of photosynthetic bacteria and a popular microalgal supplement, spirulina can be classified as both a microalgae and bacteria. Structurally speaking, it should be a prokaryotic bacterium. But, it has Chlorophyll A which is a feature of cyanophyceae microalgae.

Whatever it’s called, spirulina has a wide range of enticing reasons to grow it. Whether it’s the fact that algae produces 50–85% of the world’s oxygen, or that spirulina is so nutritious its biggest risk is giving you a nutrition overdose, spirulina will be a key part of our futures.

In this series of articles, I’ll use cyanobacteria and microalgae interchangeably when referring to spirulina, but do understand that they’re very much different things. Spirulina just happens to qualify for both definitions :)

A Quick History Lesson

Today, when algae is mentioned in regards to food, it’s often praised as some sort of “future food”; something new, never been seen before. Yet, this is far from the truth.

Spirulina has been consumed for centuries by indigenous people of Central Africa and Central America. Some African tribes, such as the Kanembu, even use it as their main food source.

Kanembu women make spirulina in to dihé, a dried cake, to sell at the market I Twitter

To Westerners, it seems futuristic and new only because of our limited experience with it. In the 70’s, when it was grown for biofuel, the tanks were made to look very futuristic to excite the world and the fact that NASA is trying to grow it in space doesn’t help with its high tech image either.

A NASA lab’s collection of spirulina I SF Chronicle

People make it out to be so much more complex than it really is. In reality, it’s the same thing women on Lake Chad have been doing for centuries, just with some extra machines. The food is the same.

Women in Chad dry out their spirulina harvest I CNN

Why Spirulina?

Once people get past the whole eating algae thing, there are pretty much only two types that get talked about: spirulina and chlorella.

Epic showdown 🏆

Chlorella, not to be confused with cholera (hehe), is the second most consumed microalgae after spirulina. Though to many they’re just green powders, they have lots of differences and reasons why I think spirulina will make a greater impact.


While spirulina is a spiral-shaped, prokaryotic bacteria, chlorella is spherically shaped and eukaryotic. Chlorella can get up to 100 times larger than spirulina .Chlorella is single-celled and so is spirulina if you look at it closely, but because spirulina cells stick to each other they also function as one whole multicellular, photosynthesizing cyanobacterium.


Spirulina prefers low-alkaline conditions and can grow in fresh, brackish, or salt water. It requires an abundance of sunshine and moderate temperatures. Chlorella on the other hand prefers growing in freshwater occupied by other organisms. This makes it more challenging to harvest than spirulina.

Special Care

Spirulina doesn’t have the hard, indigestible, cellulose rich cell wall that chlorella has, making processing cheaper. Surprisingly, the most highly regarded method of cracking chlorella’s cell wall is gently washing it with sound waves! Spirulina’s digestibility means you don’t need to pay extra for lullaby treatment ;)


Nutrition wise, they’re hard to compare since each has different strengths.

Spirulina contains more essential amino acids, protein, B vitamins, and vitamins C, D and E; chlorella has more vitamin A, iron, omega-3, and zinc. It really depends on what you’re looking for, and you can totally eat both!!

Carbon Sequestering Machine

It seems like every other company is now “sustainable” because they plant trees. Here’s the thing. Trees are great, but they need a lot of space and a lot of time.

Is tree planting oversold? I The Conversation

Algae on the other hand is 400 times more effective at removing carbon dioxide from the air than trees and needs far less space to grow.

Hypergiant, an AI company working on algae carbon sequestration boasts that a container of algae the size of a refrigerator can sequester as much carbon as an entire acre of trees!

Company Hypergiant’s fridge sized carbon sequester I Hypergiant

Not only is this great news for climate change, but they’re thinking of putting them inside of buildings to reduce indoor carbon levels. Offices already have around 405 parts per million of CO2, but in conference rooms, it can soar to 2,000 parts per million!

Now that you know what spirulina is and why I chose to dedicate four entire articles to it, go on to the rest of them!

Next up, Different Methods of Growing and Harvesting Spirulina. 👩‍🌾

Or, skip to article 3, The Nutrition and Applications of Spirulina. 🥗

If you’re really impatient, go all the way to the last article, Barriers to Adoption. ✋

Leave claps, follow, and connect with me! LinkedIn, Twitter 🙏



Klara Zietlow

Passionate about the future of food and the environment. Likes animals too :)