TIPS
Most miniatures are not bottled to last for more than a few years. The seals blow and evaporation occurs. Miniatures from some producers are much worse than others. Early G& M miniature flasks are good but later Connoisseurs Choice miniatures are poor. Miniatures from Cadenhead and Springbank are bad for evaporation but those from Signatory and James MacArthur are generally very good. Covering the seal with a laboratory tape, "Parafilm M" is the best method that I have found to reduce the effects of evaporation. I now put a piece of that tape round the cap on each of my miniatures. The tape is waxy and not adhesive so no damage occurs to bottles or labels.