I melt down the butters and waxes first (cocoa, shea, beeswax,) combined with my oils and cetearyl alcohol.After It cools and solidifies the following day I add aloe that has a preservative already in It and whip It together with a mixer. I have not had an issue with the formulation remaining solid, but should I be adding a preservative again to the final product after adding the aloe even though the aloe has a preservative in It.