As you use your machine more and more, you may begin to notice that calcium (or any other layer of minerals) has formed. If you regularly clean each of the compartments then this is less likely to happen; but, it can still persist and you should know what to do when it does. The good news is the process is relatively painless. To begin, wash all the components as you normally would (either in the dishwasher or with hot and soapy water). After allowing them to dry, add one quart of vinegar to fill the mark of your machine. Then, allow it to steam for around 20 minutes or so. From there, allow everything to cool and clean everything once again (in the same method you did the previous time).