The soluble protein in the wort assures:
- the nutrition of the yeast in fermentation
- the quality of the moss
- the softness of the beer
- so the good balance of the beer

The worts too rich in soluble protein :
- clarify badly
- give less limpid beers and less good conservation

The optimum content is between 4 and 4,7 according to the content in total nitrogen on dry malt and the brewer's specifications.