>How do you recommend to preserve summer pollen for early spring feeding? (in addition to the amount the bees preserve)
I leave it in the hive... but if you want to collect pollen from a pollen trap, you can, and the bees will gather that if you put it in an empty hive in the spring. But usually they have pollen by the time it's warm enough to fly, from the Maples etc.
>I was thinking about putting pollen loaded combs into the super, feeding sugar syrup so the bees fill syrup on top of the pollen and cap it with wax.
Usually they don't cap pollen. I would put the pollen where the bees usually put it, under the brood nest.
>This way the frame could be preserved till next spring in a store.
Bee bread keeps much better than pollen. It's pollen that has a short nutritional life, not bee bread. The bees cover it in honey after it's fermented to keep it.
>Another way could be pushing freshly trapped pollen grain in a jar. In the anaerob environment it would ferment. The pollen grain probably has enough sugar and yeast for this.
But the environment in the hive is quite different and it may ferment quite differently. Yes it has enough of the microbes in it as the bees inoculate it when they gather it, but I would not be so sure I can duplicate the conditions in the hive.
>Apart from being profitable and labor requirement, could it work?
What exactly is the goal beyond the goal and methods the bees already use to stock up pollen for the winter?