Here is one of the things I like to do when I have extra spare time. On days that I am not brewing, and I find myself with time to kill, I jar up some water and can it using a pressure cooker. This gives me a stash of sterile water and jars to use for yeast washing. Just fill super clean jars with your brewing water, place on lids and then follow your pressure cookers directions. I let them boil for 15-20 minutes at 15 psi.