Particular attention is paid to the preparation of the espresso and the relevant scientific research. It is also about the correct interaction of coffee and espresso machine. Café vs. home preparation Home espresso machines have increased in popularity with the general rise of interest in espresso. Today, a wide range of home espresso equipment can be found in kitchen and appliance stores, online vendors, and department stores. The first espresso machine for home use was the Gaggia Gilda. Soon afterwards, similar machines such as the Faema Faemina, FE-AR La Peppina and VAM Caravel followed suit in similar form factor and operational principles. These machines still have a small but dedicated share of fans. Until the advent of the first small electrical pump-based espresso machines such as the Gaggia Baby and Quickmill 810, home espresso machines were not widely adopted. In recent years, the increased availability of convenient counter-top fully automatic home espresso makers and pod-based espresso serving systems has increased the quantity of espresso consumed at home. The popularity of home espresso making parallels the increase of home coffee roasting. Some amateurs pursue both home roasting coffee and making espresso. Etymology and spelling Some English dictionaries translate espresso as "pressed-out", but the word also conveys the senses of expressly for you and quickly: Modern espresso, using hot water under pressure, as pioneered by Gaggia in the 1940s, was originally called crema caffè (in English, "cream coffee") as seen on old Gaggia machines, due to the crema. This term is no longer used, though crema caffè and variants (caffè crema, café crema) still appear in branding. Variant spelling The spelling expresso is mostly considered incorrect, though some sources call it a less common variant. It is common in French and Portuguese. Italy uses the term espresso, substituting s for most x letters in Latin-root words; x is not considered part of the standard Italian alphabet. Italian people commonly refer to it simply as caffè (coffee), espresso being the ordinary coffee to order; in Spain, while café expreso is seen as the more "formal" denomination, café solo (alone, without milk) is the usual way to ask for it when at an espresso bar. Some sources state that expresso is an incorrect spelling, including Garner's Modern American Usage. While the 'expresso' spelling is recognized as mainstream usage in some American dictionaries, some cooking websites call the 'x' variant illegitimate. Oxford Dictionaries online states