I have to admit, those Thunderbrews make some good drinks. But they need to learn that theirs isn't the only decent brew! Maybe you can help me teach them that lesson...
Here, take this barrel of Barleybrew Scalder. Sneak into the basement of the Thunderbrew Distillery in Kharanos and switch it with one of their barrels of Thunder Ale. Then we'll see how their patrons like my brew over theirs! And if the barrels are guarded, then you might have to distract the guard...
(The stairs to the basement are hidden behind the table in the kitchen. There IS a guard at the barrel. Talk to him and he will give you a clue how he can be distracted for a short while - long enough for you to swap the barrels.)
The date on this barrel shows that it'll soon be tapped.
You quickly place Marleth's barrel of Barleybrew Scalder among the Thunderbrew barrels.
Upon completion of this quest you will gain: