How to read a super without opening a single cell

Every July somebody rings and asks whether a half-capped super is ready to come off. The short answer is no, and the longer answer is that the cappings are telling you something quite precise.

What a capping means

Bees seal a cell when the honey in it is below about 18 % water, and not before. So a sealed cell is a finished cell, whatever the frame around it looks like. A super that is nine-tenths sealed has a tenth of its cells still being worked on, and the honey in those cells is wetter than the honey either side of them.

Take that super off and extract the lot together and you have averaged the ripe honey with the unripe. If the average lands above about 20 % the jar ferments, and it ferments in the customer’s cupboard rather than in your extracting room.

Where the open cells are

They are almost always low down and out at the corners. Fanning moves air along the top bar and down the middle of the face; the bottom corners get least of it and dry last. If your open cells are in the middle of the frame and the edges are sealed, something else is going on — usually the colony has been moved, or a nectar flow started again after it stopped.

What we do

Supers come off at about nine-tenths sealed. The open cells are checked on a refractometer; if the reading is under 18.5 % the frame goes in with the rest, and if it is over, the frame goes back on the hive for another week or is extracted on its own and used for mead.

Nothing over 19 % is jarred here. That is a stricter line than the law asks for, and it is the only reason we can put the date of the crop on the label and not worry about it.