Please call us to troubleshoot any issues relating to the use of your Aeroccino. If we determine that the machine is defective and needs to be replaced, one of our Machine Specialists will be happy to assist you further. Please know that froth results will vary based on the type, origin, and, most important, the freshness of the milk used. Use the coiled milk frothing whisk for cappuccinos and latte macchiatos. For best results, use ice cold milk from a newly opened container. Milk proteins break down rapidly after exposure to light and oxygen and, therefore, milk that is perfectly suitable for most culinary applications can sometimes produce unsatisfactory frothing results. Also, different brands and types of milk will produce different qualities of froth. Milk quality fluctuates throughout the year, so the same brand and fat content may produce different results in the spring or the winter. The Aeroccino should be rinsed out with cold, running water, until it is cool to the touch, especially if it is being used more than once in a row. Furthermore, keep both whisks clean to ensure proper circulation of heat. Nespresso recommends thoroughly washing the surface of the Aeroccino after each use with a soft sponge and non-abrasive soap to keep from damaging the non-stick surface.