What is bee bread?

How it is made

1. 1CollectionA forager packs pollen into the corbicula on her hind legs, moistening it with nectar to make it stick.
2. 2DepositShe pushes the pollen loads off into a cell near the brood. She does not pack them down herself.
3. 3PackingA house bee packs the pollen tightly with her head, adds nectar and glandular secretions, and seals the cell surface with a film of honey.
4. 4FermentationLactic acid bacteria present in the mixture ferment it over about a week, lowering the pH and preserving it.
5. 5Storage and useThe result keeps for months and is fed to nurse bees, who convert it into brood food.

Why fermentation matters

Raw pollen grains have tough outer walls that resist digestion. Fermentation and the acidic conditions that follow break these down to some degree and make the protein and lipids more accessible. It also preserves the pollen, which would otherwise spoil or mould in a warm humid hive.

What it is for

Protein. A colony's entire brood is built from pollen, and bee bread is how that protein is stored between flows. Nurse bees eat it and convert it into the brood food they secrete from their head glands, which is what larvae actually receive.

A colony without stored pollen stops rearing brood within days. This is why pollen availability in early spring is the binding constraint on colony growth and why a pollen dearth is more urgent than a nectar dearth.

Should people eat it?

Bee bread is sold in small quantities as a supplement, at high prices. It has a genuine protein content, and the same caveats apply as to bee pollen: the health claims run well beyond the evidence, and people with pollen allergies or asthma are at real risk of reacting.

There is also a straightforward ethical point. Harvesting bee bread removes the colony's stored protein, which is a more consequential thing to take than surplus honey.