Ice cream churns the ice cream mixture while cooled inside a household freezer. Some more expensive models have an inbuilt freezing element. A newer method is to add liquid nitrogen to the mixture while stirring it using a spoon or spatula for a few seconds; a similar technique, advocated by Heston Blumenthal as ideal for home cooks, is to add dry ice to the mixture while stirring for a few minutes. Some ice cream recipes call for making a custard, folding in whipped cream, and immediately freezing the mixture. Another method is to use a pre-frozen solution of salt and water, which
Vanilla ice cream the middle of the eighteenth century, French recipes for ice cream started to include egg yolks. When the use of vanilla in foods and drinks became independent of cacao, it became more prominent in French recipes. The French used vanilla to flavor French vanilla ice cream. Vanilla ice cream was introduced to the United States when Thomas Jefferson discovered the flavor in France and brought the recipe to the United States. During the 1780s, Thomas Jefferson wrote his own recipe for vanilla ice cream. The recipe is housed at the Library of Congress. To make ice cream in the United