Carob is more temperamental than chocolate, which has a higher fat content so it doesn't burn or scorch as easily. For those who can't tolerate caffeine, carob makes a good substitute. For large quantities, melt carob chips in small batches -- no more than 3 or 4 cups at a time. Chop or grate blocks or bars of carob into smaller pieces before you melt it.
A double boiler works well to melt carob on the stove. Set the heat to medium and simmer water in the bottom pot, making sure the insert doesn't touch the water; don't let the water come to a full boil. Put the chips or chopped carob into the double-boiler insert and stir continuously with a silicone spatula until the chips become smoothly liquid, about 10 minutes.
Set your microwave to medium power. Pour the carob chips into a glass bowl and microwave them for about 30 seconds. Remove the bowl and stir the chips. Repeat this process until the chips begin to melt, and then heat them for 15 seconds at a time, stirring each time you remove the bowl. Add 1 tablespoon of warm milk or warm water to thin the mixture if necessary, gently stirring it in with a spatula until it reaches your desired consistency.
You can melt carob chips in the oven, but it takes longer than in a microwave. Heat the oven to no higher than 200 degrees Fahrenheit. Put the carob chips or pieces in an ovenproof glass or ceramic baking dish and place it in the oven for about three minutes. Remove the dish, stir the chips and repeat this process until they melt.
Melting carob directly on the stovetop can be tricky. Use a heavy-bottom pot on the lowest heat possible and continuously stir the carob chips to prevent them from catching at the bottom and burning. Keep the pot on the heat just until the chips begin to melt, then remove it and stir continuously until the chips melt completely. Stir the melted carob occasionally until you are ready to use it.