The soy sauce packet in your takeout bag isn't soy sauce. The biggest maker, Kari-Out in New Jersey, lists water, salt, hydrolyzed soy and corn protein, caramel color and sodium benzoate. No fermentation, no brewing. It's made in a couple of days by boiling defatted soy meal in hydrochloric acid, neutralizing it, then adding color and corn syrup so it looks and tastes close enough. A lot of the bottles on the grocery shelf are the same thing. Kikkoman and the Japanese government went to the UN food standards body years ago and asked that the chemical version not be allowed to use the name soy sauce. The hydrolyzed protein industry and the USDA pushed back and it stayed. The brewed ones say naturally brewed on the label. If the bottle doesn't say it, it isn't.