Some machines use a single boiler kept at steaming temperature, but water for brewing is passed through a heat exchanger, taking some heat from the steam without rising to the same temperature. Although the water for brewing remains at a lower range than that required for steaming milk, it is still too hot for proper coffee extraction without first cooling; thus this type of machine requires a cooling flush of 4–6 seconds prior to the first espresso pull. Once the machine is dialed into the proper temperature, as many shots can be pulled as required without refreshing. However, if the user leaves the machine idle again for some period, the flushing process will need to be repeated. The HX variety is found in many mid-range machines and many users install thermometers to assist them is dialing in correct temperatures. There is some controversy as to the temperature stability of the brewing water, since it is indirectly converted from steaming temperature to brewing temperature, rather than kept at a brewing temperature.
A new French press is an ideal companion on a camping trip or picnic. Our sturdy versions of French presses are available in glass, metal, ceramic and other materials. Invest in your own efficient single-cup brewers with included cups and thermal mugs to create on-the-go coffee drinks for one person. Cold-brew machines and kits are other terrific options when you prefer chilled and iced coffee beverages. Remember to order plenty of filters, tampers, descaling tabs and other coffee accessories to keep your machine fresh and bright. Clean machines with the right size filters brew the best coffee