Ice cream and gelato are among the best uses for blue spirulina powder. The product is kept cold, the colour is never baked, and the very mild, largely neutral taste of the powder lets the flavour of the base lead. A small amount gives anything from a soft pastel to a bold blue in the cabinet.
There are still a few points to get right: when the colour goes into the mix, how it disperses, how the base colour affects the shade, and how the blue looks once the product is frozen and on display.
Why blue spirulina suits frozen desserts
Blue spirulina is the blue pigment of spirulina, phycocyanin from Arthrospira platensis. Its main weakness is heat: held hot, it fades. Frozen desserts avoid that problem almost entirely once the mix has been pasteurised and cooled.
Because the powder dissolves in water, it blends readily into milk-based and plant-based mixes without the gritty texture or sediment that a whole-alga powder can leave. And since it adds very little flavour, one coloured base can carry many different flavour profiles.
When to add the colour
The key rule is to add blue spirulina after the main heat treatment. In practice:
- Hot-process gelato and ice cream: add it after pasteurisation, once the mix has cooled, for example during ageing or just before batch freezing.
- Cold-process bases: add it with the other ingredients, making sure it is fully dispersed.
- Ready-made or bought-in bases: add it to the chilled base before churning.
Adding the powder before pasteurisation risks losing part of the colour to heat, and makes the result harder to predict from batch to batch.
Dispersion: avoiding specks and streaks
Dry powder tipped into a cold mix can form small clumps that show up later as blue specks in the frozen product. The simple fix is a slurry: whisk the weighed powder into a small portion of the cold mix, or a little water or milk, until completely smooth, then add it to the full batch and mix well. A stick blender helps with larger batches.
For a ripple or swirl, dissolve the powder in a cold sugar syrup or a portion of sauce and fold it through after churning.
Dairy bases
Milk, cream and a white base give the clearest blue. Fior di latte and plain sweet cream bases are ideal: their near-white colour lets the blue show as a clean sky blue or turquoise, depending on dosage. A creamier base softens the shade towards pastel, so a richer mix may need a little more powder for the same depth of colour.
Egg-yolk custard bases are yellow, which shifts blue towards green. If a true blue is the goal, use a yolk-free base; if a mint or teal shade fits the flavour, the yellow can work in your favour.
Plant-based bases
Plant-based frozen desserts vary more in colour. Coconut-based mixes are white and take blue very well. Oat bases are beige and tend to give a softer, slightly greener blue, with almond and soy bases somewhere in between. Banana-based soft serve and other fruit bases take on the colour of the fruit, and banana and mango push the blue to green.
Test the colour in each base separately: a dosage that works in a dairy line will not necessarily give the same shade in a plant-based one.
Sorbets and acidic fruit
Blue sorbets are possible, but acidic fruit works against the colour. Lemon, lime, passion fruit and many berries can soften or dull the blue during storage. Coconut, pear, lychee and other mild, pale fruits are friendlier partners. Whatever the recipe, check the colour after a few days in the freezer, not only on the day of production.
How colour looks in the frozen product
Several things change between the liquid mix and the cabinet:
- Air: churning incorporates air, so the frozen product looks lighter than the mix. A high-overrun ice cream looks paler than a dense gelato at the same dosage.
- Surface frost: judge colour at serving temperature, once any frost on the surface has cleared.
- Light: strong cabinet lighting can fade the surface of a pan left on display for many days, so rotate stock and keep a fresh pan out.
Make the final colour decision on the finished, frozen product, photographed in the same light as your display.
Starting amounts and trials
As a first trial, start with a few grams of powder per kilogram of mix and adjust in small steps until you reach the shade you want. Make two or three test batches side by side, freeze them and compare after a day or two in the cabinet. Record the chosen dosage as a percentage of the mix so that it scales from a single batch freezer to larger production. If the product starts to taste faintly marine, the dose is too high.
Flavour ideas for a blue cabinet
Because the colour carries little flavour, decide what the blue should taste of. Vanilla, sweet cream, coconut, mint, white chocolate, almond and cookies-and-cream style bases all sit well with a blue shade. Our guide to what blue spirulina tastes like has more pairing ideas, and producers developing frozen desserts at scale can read our guide for food manufacturers.
Bulk supply for ice cream makers
Gelato shops, ice cream producers and frozen dessert manufacturers can request a quote, documents or a sample for Bulk Blue Spirulina Powder 25kg, supplied in 25 kg drums, with full pallets of 20 drums for larger producers. For home ice cream makers, the Blue Spirulina Powder – 50g is the place to start.
