Unsweetened iced tea is sometimes made by a particularly long steeping of tea leaves at lower temperature (one hour in the sun versus 5 minutes at 80-100°C). Some people call this ‘sun tea.’
In addition, sometimes it is also left to stand overnight in the refrigerator. Sun tea is easy to make, but can be toxic if not made carefully. If there are ropy-looking strands in the tea, or any other unusual-looking particles, or if the tea looks thick or syrupy chances are it has become a bacterial hotbed. A very clean container (including the spigot if there is one) and a caffeinated tea will deter bacterial growth for a few hours. Sun tea should be discarded after that period.
The Daily Omnivore 
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