I have been having this gritty balm issue for a long time. No matter how long I put the beeswax in the double boiler, the end result will be gritty balm. I even tried using the microwave oven to heat it, but still not smooth... does anyone have this problem with balms? This happened even for simple recipe like 10% beeswax, 20% shea, 70% sweet almond oil/other oils....