Is iced tea OK to drink if it was out all night?

Answer 1

One night (i.e. less than 24 hours) should be alright for most teas. More than 24 hours is risky. However, it depends on the type of tea. Some tea leaves collect mold (or mould, for you folks in the U.K.) spores more quickly than other types of tea. These days many tea manufacturers "precook" their teas, and therefore most of these collect mold at a lesser rate than uncooked teas, though these dry out much quicker.

Most Green Teas collect mold spores at a slower rate than other tea leaves, because they contain a higher level of tanic acid, which works like poison to the mold, but in moderation is not harmful to humans. If you get sick off of drinking old tea, it is likely that you have ingested mold spores. Common symptoms associated with ingesting mold spores from old tea: headache, nausea, upset stomach, diarrhea, dizziness, faintness or fatigue.

Black teas, such as what is commonly referred to as Orange Pekoe dry out relatively slowly, and therefore this why they are the most commonly used tea leaves in North America. However, if they are not "precooked" they will collect mold spores at a faster rate than uncooked Green Teas (meaning: uncooked Black teas collect mold much more quickly than uncooked Green teas.)

Note: Tea, even after brewing with boiling water is not completely immune from collecting mold spores; merely the brewing with boiling water reduces the risk.