Sometimes you get a frame of honey with many uncapped cells. The cells are uncapped because the nectar hasn’t been dehydrated to the level needed for long-term storage. For whatever reason, the bees did not finish drying those cells and now you are wondering what to do with them.
If you extract the honey from a partially uncapped frame, remember that too many uncapped cells may make the moisture content of the honey excessively high. If you store the frame, the uncapped cells may ferment. So what do you do with it?
One of the easiest ways to get rid of most of the uncapped honey is to give the frames a good hard shake. Hold the frames upside down and flick them with your wrists. The nectar will fly out like rain. Alternatively, you can gently knock the frames against a tree or a post. Since the cells of a honey comb are angled upward, turning the frames upside down aids in getting rid of the wet nectar.
Once you shake out the watery nectar, you can extract the honey or store the frame as is. However, if the honey was very close to being capped, it will probably resist your efforts to shake it free. This is fine for extracting because it is nearly the right moisture content, but storing it in the frame is more problematic.
Honey that is not capped will readily take on water from the atmosphere. Once it takes on water it can ferment. Freezing will prevent fermentation, but unless you live in the frozen north or have a very large freezer, this isn’t very practical.
That said, uncapped honey that is nearly ready to be capped may not ferment at all. I’ve seen it go either way. A lot depends on environmental factors that are difficult to assess.
If you are not planning on either extracting the honey or storing the uncapped frames, you can just give them back to the bees. You don’t even need to shake them because the bees will know what to do with uncapped honey. But give it to them before it ferments—a fermenting honey comb smells like a brewery out of place and the alcohol is not good for your bees.