A few years back there were basically no options for unsweetened black iced tea at AT&T park. The thing that closest resembled tea was Snapple which they had at most concession stands on the field level. When going to a Giant’s game, I usually resorted to getting a Pure Leaf or another brand bottled tea at one of the nearby Safeway grocery stores and brought that into the park (AT&T park allows you to bring in plastic sealed bottles). Luckily since those times, things have changed.
AT&T Park added a Peet’s Coffee to the area behind center field, next to the big green Coke bottle (see park map to the right). Just like everything in the park, the iced tea is outrageously priced at $7.50, but it is really good tasting Mighty Leaf brand iced tea. You can also specify “light ice” or customize your tea in other ways, just like you would at a normal Peet’s. This is hands down the best iced tea option in the park.
In addition to the tea at Peet’s coffee, there are also food vendors who walk around selling iced tea. The price is the same as it is at Peet’s coffee at $7.50, but I will warn you the quality is much worse. I am not sure of the brand, but it did not taste nearly as good as the tea at Peet’s. They also fill the cup really full of ice and when it’s hot outside the tea gets really watered down. They add a lemon slice to the tea, which may be ok for some, but in my experience the lemon taste has been overwhelming. My advice would be to venture over to Peet’s instead of wasting $7.50 on this iced tea.