A soy protein product having reduced astringency, which may be an isolate, produces transparent heat-stable solutions at low pH values and is useful for the fortification of soft drinks and sports drinks without precipitation of protein. The soy protein product is obtained by extracting a soy protein source material with an aqueous calcium salt solution to form an aqueous soy protein solution, separating the aqueous soy protein solution from residual soy protein source, adjusting the pH of the aqueous soy protein solution to a pH of about 1.5 to about 4.4 using at least one organic acid, such as citric acid or a blend of citric acid and malic acid or a mixture of at least one organic acid and at least one mineral acid, such as hydrochloric acid and phosphoric acid, to produce an acidified clear soy protein solution, which may be dried directly or following optional concentration and diafiltration, to provide the soy protein product.