Before refrigeration, making butter and cheese were ways of preserving milk and cream. Farm families made cheese in the hotter months when milk soured too quickly to be used for making butter. When set out in the cooler months, cream rose to the top of the non-homogenized milk. The fat in the collected cream coalesced into butter as it was agitated, or "churned." The thin buttermilk left behind was washed out before the butter was carefully packed away. New England farm women played a vital economic role in the 18th and 19th centuries by producing surplus butter and cheese to sell at the local store. The West Indies islands, devoted to intensive sugar cultivation to the exclusion of all other farming, were an important market for New England butter, cheese, and other foodstuffs.