Not so long ago someone asked me whether it was true that it took the life’s work of five honeybees to make a teaspoonful of honey. Having never seen this assertion made by a reputable source, I thought it an interesting one so I tried to answer the question. Here are my calculations:
1. How much nectar is in a teaspoon of honey?
- One teaspoon of honey is maybe 7ml in volume (depending on the spoon and its holder, of course)
- 7ml = about 10 grammes of honey (density of honey: 1.36 kg/litre according to one source)
- Honey is c. 20% water
- The bees collect nectar to make honey. Nectar varies enormously in its sugar content, but let’s say our spoonful comes from nectar that is 80% water, by weight.
- Therefore to make one spoonful (10 grammes) of honey you need 40 grammes of nectar.
2. How much nectar is made in a worker bee’s lifetime?
- A honeybee’s nectar load is estimated at 25-40mg per trip. Let’s assume 32mg /trip .
- Worker bees begin foraging for nectar when they are a few weeks old. Let’s say a worker bee lives 40 days and starts foraging at 23 days old. That’s a maximum of 17 days foraging.
- We will assume that’s raining on a quarter of these days. That gives her about 12 days foraging in her working life.
- A foraging bee will do about 10-15 trips each (dry) day. Assume 13 trips/day.
- A 32mg nectar load x 13 foraging trips/day x 12 foraging days/life gives 4992 mg = about 5 grammes of nectar in a worker bee’s lifetime.
3. How many worker bee lifetimes does 40 grammes of nectar take?
- 40 grammes nectar = 8 lifetimes of a summer worker bee.
- Therefore one 7ml spoonful of this honey is the foraging life’s work of 8 worker honeybees.
However, as every beekeeper knows, beekeeping is a matter of opinion, and this calculation is no exception. Spoons may be smaller or nectar may be more concentrated. Bees may start foraging younger, may forage longer per day or may have fewer cold wet days. They could carry more, or nectar sources may be closer to or further from the hive. Moreover, an accountant would tell you that if the spoonful of honey was fully costed, then one would have to take into account many other factors such as the honey used as fuel in foraging & honey processing, and the overhead of the queen & the male bees (it would take weeks to build all that in!). I’d say you could pick any multiple between say four and twelve lifetimes, and be quite justified.
So there you have it. A spoonful of honey is the life’s work of eight honeybees. However, as my friend Bill Kantor says, ‘your mileage may vary’.
A version of this post first appeared in An Beachaire – the Irish Beekeeper in 2009.