Sunday, July 11, 2010
Back to basics - an aside on melting butters
Sometimes your mango or shea butters can get grainy (this can happen to cocoa butter, but not as often as the other butters). The reason for this is the fatty acid profile of the butters.
Let's look at the fatty acid profile of shea butter - 3 to 7% palmitic acid (C16), 35 to 45% stearic acid (C18), 40 to 55% oleic acid (C18:1), and 3 to 8% linoleic acid (C18:2). The palmitic and stearic acid have different melting and solidification points (the oleic and linoleic aren't solid fatty acids, so they aren't relevant for this situation). After melting, the palmitic and stearic acids will eventually turn solid again, but each does it at a different temperature. If they cool slowly, the fatty acids can crystallize into large clumps, which causes the graininess. If they cool quickly, they won't have time to crystallize and you'll have a smooth product.
If you are finding your mango or shea butter is always grainy no matter what you do, you can temper it the way you would temper chocolate. Melt your mango or shea butter completely, then pour into a mould or container of some kind and put it into the fridge or freezer to cool very quickly. Remove, store in a cool dark place, then use when you need it. This should eliminate the grains you're finding in your products. (The reasons you could be getting grains even when you've been cooling the product quickly could be due to the way you're storing it, the way your supplier is storing it, and possible melting and cooling while shipping from the supplier or from the manufacturer to the supplier.) This will increase the melting point of your mango or shea butter in future products, but it will eliminate the graininess so it's hooray time all around!
This is one of the reasons I suggest melting your butters slightly and to put your products into a fridge or freezer to cool: The less we melt the oils or the quicker we cool them, the less likely we are to see the grains!