"Why is soy sauce black and soy milk white?” is a popular question in the 2000s, with the increasing usage in the United States of soy milk. “Soy sauce is black, while soy milk is white - both from the same product” was cited in print in 2006. “I’m still trying to work out why soy milk is white and soy sauce is black” was cited in 2007. “How is soy sauce black and soy milk white when soybeans are green?” was said by comedian Ron White on Twitter on July 14, 2014.
The answer is that the other ingredients in soy milk and soy sauce are different. There are also different methods and durations of soy fermentation.
Wikipedia: Soy milk
Soy milk (soymilk or soya milk) is a plant milk produced by soaking dry soybeans and grinding them with water.
A traditional staple of Asian cuisine, soy milk is a stable emulsion of oil, water and protein. Soy milk can be produced at home using a soy milk machine.
Wikipedia: Soy sauce
Soy sauce (also called soya sauce) is a condiment made from a fermented paste of boiled soybeans, roasted grain, brine, and Aspergillus oryzae or Aspergillus sojae molds. After fermentation, the paste is pressed, producing a liquid, which is the soy sauce, and a solid byproduct, which is often used as animal feed. Soy sauce is a traditional ingredient in East and Southeast Asian cuisines, where it is used in cooking and as a condiment. It originated in China in the 2nd century BCE and spread throughout Asia. Today, it is used in Western cuisine and prepared foods.
The Motley Fool—Boards
Subject: Black and white
Date: 06/03/2006 20:59
Soy sauce is black, while soy milk is white - both from the same product. What happens?
Yeast extract (Marmite, etc.) is black, while yeast is white. Ditto?
Wikipedia: Talk: Potassium bitartrate
I’m still trying to work out why soy milk is white and soy sauce is black.—188.8.131.52 03:57, 24 October 2007 (UTC)
Straight Dope Message Boards
Strain of THought
11-11-2007, 07:07 AM
How come soy sauce is black and soy milk is white?
I just noticed this this morning while eating my wheat-free cereal with my cow-free milk. I know why regular milk is white- something to do with really high refraction- and I figure all milks probably have that in common. But soy sauce is ostensibly made from the same stuff- what gives?
Why Only Cow Milk?
Feb 5, 2008, 12:03 PM
Why is soy milk white, but soy sauce is black?
Does it come from black soy sheep?
Overhead on the Uptown 6 train: “If soy milk is white, then why is soy sauce black?” #unsolvedmysteries
2:26 PM - 18 Jun 2012
Soy milk is white and soy sauce is black?
1:11 AM - 13 Nov 2013
How is soy sauce black and soy milk white when soybeans are green?
12:15 PM - 14 Jul 2014
Interesting...soy sauce is black, soy milk is white and yet soybeans are green.
4:34 AM - 28 Aug 2014