Spirulina (Arthrospira platensis) is a blue-green microalgae cultivated in freshwater ponds and harvested as a dense, nutrient-rich powder. It has a long history as a food source and is now widely used in both food and cosmetic applications for its distinctive colour. We use organic spirulina powder in our Lemongrass Citronella Exploring Soap, Green Zen Refreshing Soap, and Pine Forest Refreshing Soap, where it serves as a natural green colourant.
Why spirulina, not a synthetic dye
Achieving a true green in cold-process soap without synthetic colourants is harder than it sounds. Many natural greens fade quickly or shift unpredictably during the cure period. Spirulina's deep blue-green pigment, a combination of chlorophyll and phycocyanin, holds its colour reasonably well through saponification, settling into the soft sage and teal tones you see in the finished bars.
For a brand built around avoiding synthetic fillers, this matters. Spirulina lets us achieve a genuinely green soap using a whole-food ingredient rather than reaching for an oxide or lab-made pigment. The colour comes from the same compound that makes spirulina green in its natural growing environment.
What it brings beyond colour
Spirulina is naturally rich in proteins, antioxidants, and trace minerals. While the brief contact time of a rinse-off soap means we don't make claims about absorption or skin benefit, the algae does contribute a fine, slightly mineral texture to the bar and is part of what gives these green soaps their distinct character beyond simply looking different from our other formulas.
How the colour changes during cure
Fresh spirulina soap batter starts out a striking, almost teal-blue green. As the bar saponifies and cures over four to six weeks, the colour mellows into a softer, more muted sage. This shift is normal and expected with any natural colourant. The intensity you see in a freshly cut bar will differ from a bar that's been curing for a month, and from bar to bar there will be some natural variation, which is part of what distinguishes a naturally coloured soap from one using a consistent synthetic dye.
Organic certification
The spirulina we use is certified organic, meaning it's grown and processed without synthetic fertilisers or pesticides. For a powder ingredient with a fine, easily airborne texture, sourcing from a certified supplier gives us confidence in both the growing conditions and the processing standards behind it.
In our products
Spirulina currently appears across three of our soaps: Lemongrass Citronella Exploring Soap, Green Zen Refreshing Soap, and Pine Forest Refreshing Soap. It's become something of a signature for our green-toned bars, an ingredient that lets us reach for colour without reaching for anything synthetic.
