I use a trace mineral supplement from Trace Minerals Research,
www.traceminerals.com. (I have no affilliation, I just think it's a good
product). You put some drops in your water bottle and it gives you all the
naturally-occurring trace minerals and tastes like good mineral water. It's
important to use non-chlorinated water with it. The taste cravings could be
from mineral deficiencies. (Also, in Chinese medicine, the sour taste
corresponds to the liver).

-Karen