There is a great deal of anecdotal information regarding miso's ability to quickly soothe an acid stomach. Although we do not know of any medical research documenting this, scientists have reported that miso has a strong buffer activity due to the presence of protein, peptides, amino acids, phosphoric acid, and various organic acids produced during the fermentation process. In the stomach these buffers can reduce excess acidity and give quick relief. Scientists have also reported that miso's buffering ability is partly responsible for its important role as a seasoning. When mixed with acid foods, such as tomato products, miso not only buffers the acids but also mellows the flavor. Miso's ability to mellow acidic tastes is well known to Japanese cooks who prepare su-miso, an important ingredient of several sauces, by mixing rice vinegar with miso to make a paste with a refreshing balance of flavors.