He had disguised himself as a modest farmhand and asked for a jug of the best wine. This odd fellow seemed suspicious to the innkeeper, who knew all the farmhands in the area. And all the more so because he was asking for the best wine, which normally only the masters did. To be on the safe side, he added some schnapps to the tankard so that the drink would be more fiery. However, the goblin was not deceived and said to the innkeeper: "Fire and water don't make wine. A genuine Leitacher, that'll be mine!" Saying this, the Nörgele went to the door, pointed to the rows of vines with his stick and continued: "From your vineyard next year, old man of mine, you will get nothing but watery wine!" Nevertheless, the grapes flourished as they had always done. It was in a different way that the curse of the Nörgele ruined the innkeeper: whenever he served a customer his wine, it turned immediately to water. Only when he served the wine for free, did it remain pure. As a result, the dishonest innkeeper on the Kuntersweg was soon out of business.
Source: Fink, Hans, Eisacktaler Sagen, Bräuche und Ausdrücke. Schlern-Schrift no. 164, Innsbruck 1957, p.305 f.