Spirulina Powder.

A tall glass, a teaspoon of something improbably green, and a whisk. Spirulina turns juice the color of a deep pond and brings the smell of open water with it, a strange little sea in the morning kitchen.

This is Arthrospira platensis, a spiral-shaped blue-green alga grown in clean freshwater ponds and dried at low temperature into a fine, deep-green powder. Its faintly uncanny cast comes from phycocyanin, a blue-green pigment. Gram for gram it is one of the most protein-dense foods available, a concentrated source of plant protein, iron and B vitamins.

Algae of this kind were gathered from lake surfaces by the Aztecs and, separately, along the shores of Lake Chad, valued as a whole food rather than a remedy. That is still the way to keep it: a daily addition to an ordinary, varied diet.

Details

• Spirulina, Arthrospira platensis
• Grown in clean freshwater ponds, dried at low temperature
• Fine, deep-green powder with a strong green flavor of the sea

How to use

Stir a teaspoon into juice, water or a smoothie. It clumps if simply dropped in, so whisk or blend it to disperse, and fold it into something sweet or acidic if the taste of the sea is too much on its own. It is a whole-food supplement for ordinary nutrition, not a medicine, and no substitute for a varied diet or medical advice.

A little deep green for the pantry shelf, and for the long run of ordinary mornings.