It may be sweetened with sugar or artificial sweetener. When served cold, it is called "iced coffee". Espresso-based coffee has a variety of possible presentations. In its most basic form, an espresso is served alone as a "shot" or "short black", or with hot water added, when it is known as Caffè Americano. A long black is made by pouring a double espresso into an equal portion of water, retaining the crema, unlike Caffè Americano. Milk is added in various forms to an espresso: steamed milk makes a caffè latte, equal parts steamed milk and milk froth make a cappuccino, and a dollop of hot foamed milk on top creates a caffè macchiato. A flat white is prepared by adding steamed hot milk (microfoam) to espresso so that the flavour is brought out and the texture is unusually velvety. It has less milk than a latte but both are varieties of coffee to which the milk can be added in such a way as to create a decorative surface pattern. Such effects are known as latte art. Coffee can also be incorporated with alcohol to produce a variety of beverages: it is combined with whiskey in Irish coffee, and it forms the base of alcoholic coffee liqueurs such as Kahlúa and Tia Maria. Darker beers such as stout and porter give a chocolate or coffee-like taste due to roasted grains even though actual coffee beans are not added to it. A number of products are sold for the convenience of consumers who do not want to prepare their own coffee or who do not have access to coffeemaking equipment. Instant coffee is dried into soluble powder or freeze-dried into granules that can be quickly dissolved in hot water. Originally invented in 1907, it rapidly gained in popularity in many countries in the post-war period, with Nescafé being the most popular product. Many consumers determined that the convenience in preparing a cup of instant coffee more than made up for a perceived inferior taste, although, since the late 1970s, instant coffee has been produced differently in such a way that is similar to the taste of freshly brewed coffee. Paralleling (and complementing) the rapid rise of instant coffee was the coffee vending machine invented in 1947 and widely distributed since the 1950s. Canned coffee has been popular in Asian countries for many years, particularly in China, Japan, South Korea, and Taiwan. Vending machines typically sell varieties of flavored canned coffee, much like brewed or percolated coffee, available both hot and cold.