Brewing, plain and simple. We have cooking and cooking does yield some drinks but we need more. I hate having to buy drinks because my shaman goes through mana very quick. I would have to carry around four to five stacks of drinks around in order to enable myself to continue on for the same time that any other class can. Luckily for me a friend of mine has a mage and makes me food and water whenever I need it.
But back to the issue at hand, brewing. Potent potables anyone? Maybe not nessicarily that but SOMETHING that gives out mana for normal world drops.