To achieve effective hemiacetal or acetal formation, two additional features must be implemented. First, an acid catalyst must be used because alcohol is a weak nucleophile; and second, the water produced with the acetal must be removed from the reaction by a process such as a molecular sieves or a Dean-Stark trap. The latter is important, since acetal formation is reversible.
pKa in different solvents (calculated & experimental)
Benzoic acid EtOH 10.25 9.99
Benzoic acid Water 4.21 4.07
Benzoic acid MeOH 9.41 9.25