You get a powder (microcrystals) instead of discernible crystals?
I always like to recrystallize methyl esters from methanol if using an alcohol - no chance of transesterification.
If you are getting a powder, that means the temperature/solubility curve is very steep - so you can suddenly become greatly oversaturated and have rapid crystallization.
You can - dissoive to saturation at room temperature. Then add a known amount of extra material - don't saturate at hgh T.
Or - lower the temperature more slowly.