Also, what is it? I'm vegan so I want to know if it's ok for me to eat
No. Lactic acid is the by product from fermenting a sugar with a bacteria. Such as fermenting meat to create salami, or making yougurt, cheese, sauerkraut . . .just to name a few foods that ferment. Lactic acid is not related to lactose, the natural sugar of milk. They just sound the same.
@ChefOno - All due respect, I am in the fermentation business, your explanation is a bit of a stretch. Lactic acid can be formed by "bugs" that have no relationship to lactobacillus. Look at the strep bugs used to produce salami. When you go out and exercise, your body produces lactic acid . . .produce too much and you get cramps. And yes, soy sauce has lactic acid . . at least the good quality ones that are fermented.
So soy sauce is NOT vegan, correct?
I never said that. Most soy sauce or shoyu on the market that I am familiar with is made from soy beans, wheat, water and salt that is fermented. There is no animal derived ingredients that I know of in the product, including the bacteria culture used to create the fermentation. If you have a health issue with wheat, than try tamari, which is wheat free soy sauce.
Traditionally fermented soy sauce came out of ancient China and Japan, over 500 years ago. There were no dairy animals (well, Mongolia, but don't go there), thus no dairy in the sauce. Soybeans, water, wheat, salt are the ingredients listed on the most traditional bottle in my pantry, Ohsawa Nama Shoyu. I would guess that lactic acid listed in the ingredients indicates a shortcut taken by the producer, who uses a chemical to replace a long fermentation time.
If you're not comfortable with this question, your best bet to avoid any question is to use Bragg's or a similar non-fermented sauce. It is different, and can't have the nuanced taste that develops during a (traditional) 12 to 18 month koji fermentation. (information with help of The Book of Tofu, Shurtleff & Aoyagi)
There is no reason to list lactic acid as an ingredient, since it is formed during the fermentation process. Note that real sauerkraut, cheese, yougart, salame (only that a lactic acid starter culture is used) or any other fermented product do not list lactic acid as an ingredient. I could go on listing many other foods where a chemical reaction is created during processing and the by-product of that reaction is not listed. Fermentation is a organic (meaning living in this case, not certified Organic) chemical reaction . . . as is dough that rises with the reaction of yeast. CO2 is formed in trapped in the bread, but not listed on the ingredients panel.
A question goes back to @alexia1996 . . . is the soy sauce you are referring to in your question have lactic acid in the ingredient listing? If so, I would feel 99% sure that it is corn derived (commercially created by fermenting sugars from corn). ADM (Acrcher Daniel Midland) is the largest manufacture of lactic acid for food use in the USA, possibly worldwide. In Europe, most of the commercially available lactic acid is derived from beet sugar, because of the anti-GMO sediment and corn is not as large an ag crop as beets. Yes, the ADM derived lactic acid will have come from GMO corn.
Yes it does.
Then the lactic acid is an added ingredient, hence it being on the label. I would then venture to say that this is a non-fermented soy sauce, lactic acid added to simulate the taste of a fermented soy sauce.
So you're saying it's vegan?
Yes, since I am 99.99% sure the source of lactic acid is corn