How can you tell if Soy Milk has spoiled?

[Khadaji]

I have some soy milk in my refigerator and I’m wondering if I’ll know when it has gone bad. I only drink milk occasionally and when I was drinking cow’s milk I always knew it had gone bad from the smell. Will I be able to tell with Soy?

[Tuckerfan]

It turns into tofu when it goes bad. Sorry, I got nothin’, but a free bump for ya.

[mittu]

I’m not sure what it smells like but according to many recipies which require sour soy milk it can be synthesised by adding 1 tbsp. of vinegar to 1 cup of fresh soy milk. So here’s the plan: Go to the shops, buy more soy milk, add 1 tbsp. of vinegar to 1 cup of the fresh milk then compare the smell to what you have in the fridge. If they smell the same then your “milk” has gone udders up, so to speak.

On the plus side, if you find your soy milk has gone sour you can still use it to make “Easy Biscuits” or “Sweet Potato Corn Bread” amongst other things.

[Earthling]

FAQ from Silk: How can I tell if my soymilk is spoiled?

Your soymilk may be spoiled if:
The package looks abnormally bloated; when poured, the soymilk appears to have thickened slightly; the color of the soymilk has changed…; it is so thick that it won’t pour easily, or it looks like a milk shake and has curds or lumps.

Fresh soymilk does not have a strong odor. If there is any smell resembling dying flowers, sour milk or chemicals, the product is mostly likely going bad.

A slightly ‘off’ or beany flavor indicates that spoilage has begun. A bitter, metallic, earthy, grassy or extremely sweet taste means it is definitely past the drinking stage.

FAQ from Kikkoman: How can I tell if my soymilk is spoiled?

Some signs that your soymilk may have “gone bad” are: unusual smell or color to your soymilk, a bloated or punctured carton, soymilk that has gone past the expiration date printed on the top, or soymilk that doesn’t pour out smoothly or has turned “lumpy”.

And, from Vegetarian Times:

An opened container keeps in the refrigerator for 4 to 6 days. You will know when soy milk goes bad–it develops a clotted texture and an off flavor.

[Khadaji]

Hmmm. Mine has been open longer than 6 days. Maybe it is time to dump it.

Thanks for the links.

It turns into tofu when it goes bad. Sorry, I got nothin’, but a free bump for ya.

Thanks for the bump.

[davenportavenger]

Have you looked at the expiration date? It takes soymilk three months to expire. And I doubt you’d get sick from drinking sour soymilk like you would from regular sour milk; there are not as many live bacteria in it, and that’s why rotten milk makes you sick. It would probably just taste funny. I’ve never drank it past the expiration date, though (when I can afford soymilk it disappears in a day, that stuff is awesome), but the really late expiration date seems to say that even if you did drink it past then, it probably wouldn’t be as bad for you. Like eating cereal past expiration: won’t make you sick, it just might taste a little off.

[Excalibre]

There’s a pleasant beaniness even to fresh soymilk. I’m not sure I could detect a change on that account. I’ve kept soymilk open for probably as much as two weeks at a time, and it’s never caused any ill effects.

[InternetLegend]

I tend to keep opened soymilk for two or three weeks at a time myself, so I’ve had plenty of occasion to see what it looks like when it’s spoiled. Although it doesn’t start to smell bad until long after spoiled milk would, it gets a kind of thickened, slimy texture to it. When it starts looking syrupy, I know not to use it (and I don’t believe I’d even try using it in baked goods).