Assuming you mean to hydrolyse cellulose (or other polysaccharides) to sugars to ferment them, a somewhat better procedure is to use cold super-concentrated hydrochloric acid, i.e. under mild HCl additional pressure. It takles about an hour, then you evaporate off the acid under vacuum and recover the acid. The sugars can then be fermented after neutralizing the traces of acid remaining. The yields are very high. Sulphuric acid gives only about a 35% yield because the sugars further degrade to hydroxymethyl furfural, and then nominally to levulinic acid, but also to a lot of brown tar. The HCl route is so cold that doesn't happen. A plant operated during WW II in Germany.

Diluted hydrochloric acid is preffered. However,apart from the type of acid, the medium pH has a significant impact on fermentation process. Yeast preffer to do their optimum efficiency at the pH of 5.