I make it in five gallon batches, too -that's the size of my carboys. It's a lot, sure, but I plan to be sampling this for 10 years or so, if I can eke it out that long. And of course, a lot of it gets given away.

AFB is American Foulbrood Disease, caused by bacterial spores, and it causes the bee larva to turn brownish, weaken, and sometimes die in the cell before turning into a bee.

In advanced cases, none of the brood survives and the bees eventually all die. Later, if another healthy hive finds the dead one and raids its stores, it can become infected also, because their honey will be loaded with AFB spores. AFB is the primary reason honey importation is not allowed, into NZ.

You detect it by opening up a few capped larva cells on each brood frame, and check for brownish larva (they should be white). Another sign is sunken caps on sealed brood larva, with decaying dead larva inside which "rope out" when you stir the contents of the cell with a matchstick. I've been told there is a distinctive odour as well.