Given that fat and water do not mix, the melted cheese topping then sits nicely above the puree.
Dr Maureen Cooper, from Stirling University, says the answer lies in the properties of the tomato puree.
The traditional pizza base has fibres which trap water, preventing it from seeping through to the cooked dough and making it soggy.
Given that fat and water do not mix, the melted cheese topping then sits nicely above the puree.
Dr Cooper explained: "We all see the grease on plates which causes washing-up liquid to float on top.
"That is because oil and water do not mix. That same phenomenon can be applied to the cold pizza.
"Because the fat does not go through to the base, the pizza itself tastes so much better.
"That is not the same for chips, which are not recommended for eating cold.
National Science Week
"Unfortunately the chips don't taste nice because the fat congeals. It's the fat which goes solid when the food is no longer warm.
"However, oil at room temperature stays liquid, which feels much nicer on the tongue."
Dr Cooper made public her research during the recent National Science Week, which set out to make the subject more interesting to the general public.
The scientist also thinks she can explain why cold curry tastes much better the day after.
"Spices that are used to make a curry are those which promote digestion.
"So, in terms of aromatherapy, things like clove oil, ginger and garlic are all essential oils which help digestion. While the left-over curry sits, the oils and spices are continuing to tenderise the meat.
"By eating curries we are giving ourselves an aromatherapy session from the inside out."