The effect of saturated monoglyceride (SMG) content of four B100s on the cloud point (CP) of blends with four diesel fuels was examined. Detecting CP with a more sensitive light-scattering method allowed observation of an early (higher temperature) CP in blends containing approximately 0.01 wt.% to 0.03 wt.% SMG. Blend samples with SMG content in this range may be particularly prone to unexpected filter clogging above the measured CP. Results for a 140 blend sample matrix revealed that SMG content had a larger effect on CP than other blend properties. An increase of 0.01 wt.% SMG in a biodiesel blend increased CP by as much as 4 degrees C. At a constant SMG level, increasing biodiesel content lowered CP, as did increasing the diesel fuel aromatic content, by improving the solubility of SMG. This implies that lowering the SMG content of a B100 allows preparation of higher biodiesel content blends having the same or lower CP. Increasing the unsaturated monoglyceride-to-SMG ratio by blending in monoolein lowered CP, presumably because monoolein inhibits nucleation of SMG. In most blends with SMG content above 0.01 wt.%, polymorphic phase transformation of crystallized SMG (converting from the metastable alpha-form to the less soluble, stable beta-form) was observed. (C) 2013 The Authors. Published by Elsevier B.V. All rights reserved.