To condense is to make something denser by removing water, most familiarly in condensed milk, where milk is evaporated to about half its volume. Sweetened condensed milk adds sugar, which preserves it and gives the thick, syrupy product used in desserts worldwide; unsweetened evaporated milk is the plainer cousin. Condensing intensifies flavour and extends keeping quality by lowering water activity. The term also covers the physical change of vapour to liquid, as when steam condenses on a cold lid. In food manufacturing, vacuum evaporation condenses at lower temperatures, protecting delicate flavours from heat damage.