The creaming behaviour of model pourable salad dressings has been stud
ied over a wide range of xanthan and oil phase concentrations. They we
re produced by mixing a colloidally stable emulsion with xanthan solut
ions. The model dressings were completely flocculated by depletion at
all xanthan concentrations >0.1 g/l. Creaming behaviour was in three p
hases: an initial delay phase, followed by more or less linear creamin
g and finally cream compression. Delayed creaming has not been reporte
d previously. It is of great practical interest, because a complete ab
sence of creaming is the aim of successful dressing formulation. The l
ength of the delay phase was proportional to the emulsion concentratio
n, inversely proportional to the oil/aqueous phase density difference
and scaled over move than four orders of magnitude with the xanthan co
ncentration to powers between 3 and 4. Traditionally, the stabilisatio
n of salad dressing by xanthan is explained by the yield stress of its
solutions. It is shown that they do not have one, and we offer an alt
ernative explanation. It is suggested that the depletion flocculation
of the emulsion droplets, induced by the addition of xanthan, leads to
the formation of a particle network and that it is the time-dependent
yield stress of this network which stabilises the dressing.