Yes, you can.
There's no reason to assume that it can't be sold, after all.
However, the potential to make a profit is very low. Assuming level 20, you can convert 20 pints of water into beer per cast of the spell. Ale (beer) is priced at 4cp per mug (pint). Since you are selling the beer, you get half the market price: 2cp. 20*2cp = 40cp, or 4sp, for 20 pints of beer. At level 20, you can cast ~36 level 1 spells per day (not counting bonus spells from a high WIS score or your domain slots), so if you spent all of your slots to prepare this one spell 36 times and cast it 36 times, you could make, at most, 14gp and 4sp per day. One day of adventuring nets you far more than that at level 20 (even at level 1 a full day of adventuring nets you more than that), so why even bother?
To clarify: the reason the cleric could cast Enhance Water 36 times is because the rules allow a caster to prepare lower level spells in higher level spell slots. Clerics at level 20 receive 4 slots (+1 domain slot) per spell level, not including bonus slots granted from high WIS scores, so the assumption is that for maximum profit, the cleric would prepare Enhance Water in every available spell slot, all the way up to 9th level spells.