The ampacity of a particular gauge of wire depends on its insulation, the ambient temperature, how many current carrying conductors are bundled together and the length of the run. UL recommendations for STO, STOW, SOOW, SJOOW etc. cords (available at home improvement stores and commonly used for such applications) with 2 current carrying conductors for runs of under 50' are for 25 amps. I believe the UL recommendations are based on NEC table 400.5 which allows 25 amps at ambient temperature up to 30 °C (ampacity must be adjusted down for higher ambients). Ampacities must also be derated if more than 3 current carrying conductors are bundled (to 80% for 4-6 and further for more). I don't remember ever seeing a recommendation limiting loads to 80% of specified ampacity under other conditions so I'd like to see a reference to that.
My reason for going on about all this is that I'm always seeing statements like "12 gauge is good for 25 amps" without the conditions under which it is good for 25 amps being specified. Certainly in almost every application contemplated by people on this forum there will be 2 current carrying conductors, the ambient will be less than 86 °F and they will buy SJOOW at Home Depot but readers need to be aware that there are conditions attached to the rated ampacities. Brewing outdoors in Tuscon is mid August? You might want to check into the temperature derating issue though in this particular case you have quite a bit of margin as you are only using 2000/120/25 = 66.7% of the 30 °C ampacity.
