As flipflopgirl stated, when available, you should take the time to buy a quality bean pod and stay away from the prepackaged store bought type.
Many spice and import shops have single bean pods available from their bulk stock. There is also a good variety of fresh bean pods available online.
I would not use price as a quality indicator. Always try to confirm that the beans were hand picked and the vendors bulk beans arrived recently.
Still there's usually no indication of age. A good pod will start to crystallize after time. It may appear as mold but it is perfectly fine to use. I hear about molding beans frequently but have never had any myself. I'm not sure if a product with most of it's moisture removed is going to mold. ? not a scientist :>)
A ripe/mature bean should be hand picked when the tops are starting to turn a yellowish brown. This type of bean will be able to impart flavor even if it's dried to the point of a hard stick of wood or nail.
There are many chefs who actually want this type of bean because they chop or grind the whole bean for use.
I'm not on board with plumping a bean with hot or cold water especially if the liquid is going to be discarded. I personally feel this type of imparted flavor seems to have a cleaner/filtered flavor.
If I take a few pods home for use, I usually store them submerged into my granulated sugar container. I feel when the flavored sugar is cooked or baked the vanilla flavor becomes more of an added aroma than a direct hit on the taste buds. If asked, I would put this type of flavor in my pastry umami category.
If plumping is necessary, I think it's best to have a direct use for the flavored liquid.
This is just my preference, but I usually omit the use of the fresh seed itself in my formulas. I usually flavor the liquid ingredient. I find the fresh seeds to be somewhat overpowering and bitter to the taste. The seeds are usually the byproduct of our pod usage and we use the seed in recipes if the look is needed.
Our bean pod and seeds afterlife is usually in our simple syrup. We avoid using any fresh pods for liquids that are stored and not used quickly. They seem to turn the liquid rancid quickly. Not sure but I imagine the fresh pods contain contaminants.
I'm also not a fan of using liqueur/alcohol to plump beans. Not against flavored bottled liqueurs, different animal. But the alcohol and seed flavors are an overpowering pair. Add evaporation and I feel it enhances the bitter flavor. Just me though.
When you say dehydrate in vanilla extract do ypu mean fill the pod bottle with extract? Would not a warm liquid work better so if a recipe csll for liquid warm it and let pod soak init? I bought my beans from spice barn just haven't used all of them