I have been working on hybridization processes for 5 years now and conserving pollen is a step for varieties that do not flower at the same time. My practices refer to putting it on a smooth paper (like the one used in baking) since it does not have pores where the pollen catches. I put something on them that creates a dim heat source (26/30°C) like a lamp and I leave it for a while to see how the collected stamens feel like they slide like pebbles or dirt. They give a dry sound like earth but the color is orange or yellow, if it turned white it already died. It's all about using practice as a teacher. and I preserve it with silica gel stones in small containers. some go to the vegetable drawer and others go to the freezer which is -15°C or so. When you take them out to use, they are rehydrated with 100 ml of water and 3 g of sugar. There are times when it looks white when you take it out and other times it looks yellow-orange. the second is fertile. Sometimes I take closed stamens that are very orange-yellow or sometimes I use open stamens. the rest is practice. The key is to repeat many times to see which one works.
