The present invention relates to a method for producing a processed solid soy protein product derived from soy flour (SBM), the protein product comprising 65-75 wt.% Protein per dry matter, has a mass ratio of protein to potassium of at least about 50: 1 and a content of dry matter of at least about 90%, wherein the product is substantially free of sodium, and at least about 65% by weight of difficult to digest oligosaccharides contained in the SBM from which the protein is obtained is removed； and the method includes the following steps: 1) providing an initial mixture comprising ground or crushed or otherwise ground soybean and water； 2) leaching the initial mixture under conditions when the amount of dry matter in the initial mixture is from 8 to 20 wt.%, For 0.15-6 hours at a temperature of 5-65 ° C and at neutral pH； 3) separation of the mixture after leaching into the liquid fraction and the first solid fraction； 4) adjusting the pH of the liquid fraction from the initial mixture after leaching with acid to a value of 3.5-5.5； 5) passing the acidified liquid fraction through a separation device, such as a decanter centrifuge or the like, whereby the spent liquid is separated and an additional solid fraction is collected； 6) combining the solid fraction from the initial mixture after leaching with the solid fraction collected from the separation device； 7) drying the combined solid fraction to a dry matter content of at least 90%； 8) whereby the total amount of consumed water in the method, calculated on the starting material initial SBM, is approximately 10-fold or less of the amount of SBM. It also relates to a processed solid soy protein product obtained from soy flour, the protein product comprising 65-75 wt.% Protein per dry matter, has a mass ratio of protein to potassium of at least about 50: 1 and a dry matter content of at least about 90%, the product being substantially free of sodium, and at least about 65% by weight of difficult to digest oligosacch
