Abstract: The quality of milk froth includes aroma, luster, flavor, taste, etc. In order to clarify the relationship between steam performance and the quality of milk froth, the effects of steam performance on the quality of milk froth were investigated by comparing 6 different brands of expresso coffee machines. It was found that the steam performance of espresso coffee machines significantly affected the quality of milk froth. When the foaming time was short, the water content of steam was low, and the precision was low, the quality of milk froth was at a high level. Among 6 espresso coffee machines, the steam performance of foreign brand F was the best. In foreign brand F, the foaming time is 57 s, the water content of steam is 9.50%, and the precision is 1.40. Besides, the milk froth made by foreign brand F had the best quality with 87.08% stability, 46 s milk density, and the highest score in subjective evaluation. In addition, there was no significant difference between domestic brand D and foreign brand F in terms of steam performance and milk froth quality.

Key words: Espresso coffee machine, Steam performance, Milk froth, Quality