The cooling rates of a variety of liquids in porcelain mugs
are shown in Fig. 4. The results reveal similar cooling curves
for water, instant coffee and tea. The addition of one or two
teaspoons of sugar to the beverages did not affect cooling. The
introduction of milk (4 8C) resulted in lower temperatures and
cafetie` re coffee had consistently the lowest temperatures.
Indian tea had a similar starting temperature to water, coffee
and tea but cooled more slowly than these liquids. The various
types of milk tested were found to cool at a slower rate than
the other agents as demonstrated in Table 1 with the time
taken for liquids to reach 70 8C, 60 8C and 53 8C.