Years ago we bought a stirrer/hotplate made by Corning. It has a nice flat top that will hold 9-10 Mannitol bottles. We turn it on a low setting so the bottles don't get too hot to handle and it does a fine job of dissolving the crystals. Actually, that's its primary function anymore since we hardly ever use it as a stirrer!
We have what we call the Hot cabinet. It is a metal cabinet in the storeroom area that has a 150 watt light bulb..it stays on 24-7 and keeps the mannitol nice and warm, no crystals.
We used to have the hot cabinet but switched to the hot plate. Both work well, I'm not exactly sure why we got rid of the hot cabinet. I think because we needed the extra room.
We place ours on top of the water tank of our commercial coffee maker. As the water heats up for the coffee, it makes the metal lid heat up. It takes a few days, but they do dissolve without getting too warm. Years ago, we had a styrofoam cooler that came with a light bulb inside but it eventually cracked on the side and we tossed it. Up stairs in surgery, they keep a flat for the heart room in the blanket warmer.
We had a cabinet with a light bulb (to generate heat) but we were told that constant monitoring was required (like refrigerator temperature logs). So, we bought a warmer from Cole-Parmer that has a temp gauge.
We have an incubator with a thermometer that we use so that we can monitor temps. According to the PI and other sources we found, it should not be kept at constant temperatures above 86 degrees F because it may compromise the integrity of the product, so we keep the incubator at 85 and monitor.
