Is soymilk safe to drink if left in a car on a hot day(unopened) ?
Although it might seem as if soy milk, as a plant-derived product, shouldn't go bad as quickly as cow's milk, it does spoil eventually. Soy milk is derived from soybeans, which, like all plants, eventually decompose. Always follow package instructions -- and your own senses of smell and taste -- to determine whether a product is safe to consume.
Your soy milk carton should have an expiration date stamped on it. The product should be good until then if unopened; once the carton is opened, the soy milk may only last for seven to 10 days. Signs of spoilage include a lumpy texture and foul odor, much as with regular milk.
Read more: http://www.livestrong.com/article/477686-does-soy-milk-spoil/#ixzz1yWXWVqyv