Is soy milk in America similar to the type in East Asia? Finding soy milk in the States isn't very difficult - it's generally stocked in supermarkets and used as an alternative to dairy. However, I'm not sure if the flavour of typical American soy milk (even the "unsweetened" variety) is sufficiently similar in taste to the soy milk I've had in East Asia.

As an example - in Hong Kong, if I remember correctly, Vitasoy sells unsweetened soy milk with the ingredients listed as:


  Water, soy beans


Comparatively, the Silk brand that sells non-dairy alternatives lists additional ingredients on their soy milk (even the "original" variety or the "unsweetened" one), such as additional vitamins and sea salt.

Is the soy milk commonly sold in supermarkets in the US (outside of places such as Asian supermarkets) similar in taste to the type found in East Asia? I've heard that there might be some differences, but I don't have enough "experience" with this to judge if those accounts are correct.
East Asian soy milk and American soy milk taste very different, and not just because of added ingredients like sugar and emulsifiers. 

Soy beans contain an enzyme called lipoxidase, which breaks down unsaturated fatty acids into shorter chain lipids. For American markets, manufacturers presoak the beans in solvents such as calcium hydroxide in order to destroy this enzyme. After the enzyme is gone, the solvent is deactivated with an acid to form a neutral pH product. In East Asian markets, no one bothers with this added step, and just leave the lipoxidase in there.

Why the difference? Taste, mostly. Remember The shorter chain lipids mentioned before? They taste, well, bean-y. Soy milk manufacturers like Silk found through trial and error that Americans want their soybean milk to taste more like milk, and less like soybean, so this bean taste must be neutralized.

For East Asian people who grew up drinking soybean milk, soybean milk needs to taste like, well, soybean.