"Sour tang" refers to a taste or flavor that is both sour and tangy. It is a combination of sharp acidity and a sharp, slightly bitter taste. Full definition
The lovely sour tang of the sauerkraut is left to type III. (sciencenews.org)
Our guarantee: This bread will be moist, fine - grained, and easy to slice, with assertive flavor typical of rye bread: caraway and a touch of sharp mustard, with a mildly sour tang. (kingarthurflour.com)