This packet contains 7oz (200g) of Dezcal powder. Dezcal works to remove mineral build up on the heating elements of coffee brewers and espresso equipment. Mineral build up can impact your machine's ability to heat water to the correct temperature and can clog water lines. Brewing coffee below the proper temperature will not make good coffee no matter what coffee you use, and a clogged water line can cause your machine to fail! To use, mix the full packet with 1gallon (3.9l) of warm water to create a descaling solution. Add the solution to your machine's water reservoir or boiler by following the descaling instructions included in your machine's user manual. Once you've flushed all the Dezcal through your machine, it's recommended to flush your machine with a few rounds clean water too, again following the descaling instructions in your machine's user manual. Urnex CleanCaf coffee machine cleaning powder also inhibits scale buildup and works as an effective cleaner, but there are regions in the US where water scale is a particular problem and you want a specific purpose descaler.