What factor related to the ingredients may have compounded the risk associated with traditional sun tea making?

Answer

Using standard, inexpensive tea bags.

Many people used inexpensive tea bags which may not adhere to the same strict cleanliness standards as specialty loose-leaf varieties, potentially introducing more spores.

What factor related to the ingredients may have compounded the risk associated with traditional sun tea making?
sunpreparationbeveragefood safetytea