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Oct 24, 2005 03:00 PM

how long does soymilk really last?

  • d

I bought some Silk brand vanilla soymilk 3 or 4 weeks ago, and opened it right away. This is the first time I have purchased soymilk. The stamped date on the 1/2 gallon container is 12/8/05, but the container also says that it will stay "fresh" in the refrigerator for 7-10 days after opening. I had some late last week on cereal, and it still seemed fine.

How do I know when I can't drink it anymore? What does "fresh" mean in the context of soymilk, like what will happen if it's no longer fresh? What's a realistic timeframe?

I really like the product and one of the selling points is that it lasts longer than milk which is a big deal in my house where I'm the only milk consumer and not a frequent consumer at that.

Also, any thoughts or recommendations re: the brands of soymilk sold at TJ's?

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  1. How long it will keep depends on many things. How old it was, what temperatures it was exposed to, what and how many bacteria entered the carton once it was opened, and how full the container is (less full=more air=spoils quicker). I find it's good for 1-2 weeks after being opened. It keeps unopened for a much longer period than cow milk, but not a great deal longer once opened.
    Personally, I like the Silk Unsweetened soy milk, I find the Plain is still OK, the Vanilla too sweet. I don't care for the TJ one.

    1. soy milk does start to smell "funny" when it turns... not sour like milk, but off. it gets clumpy too as it separates from sitting. I have kept my soy milk for up to two weeks without a problem.

      I agree with two forks though... try the plain soymilk, the vanilla is awfully sweet.

      might I offer another suggestion? I buy mine in quarts so that I go through it faster... they also sell it in those steri-packs that don't need to be refrigerated until opened. (those are also quart sized) I usually keep a few of those on hand for in between trips to the store. the only place locally that consistently has the steri-packs is whole foods.

      1. If fresh unsweetend soymilk is available or if you make your own soymilk at home from one of those machines. It will be anywhere from 5-7 days.

        The ones you purchase from a supermarket which has sugar and other compounds in the milk, usually will last a while. Just don't drink directly from the mouth of the carton or gallon. If you do that then you can expect your soymilk to go bad within 2 weeks or less than 3 days with fresh.

        BTW, you will definately know when the soymilk goes bad. It will omit a rotten smell, whereas milk doesn't have a strong smell until take that unforgettable gulp.

        1. I find that American brands (Silk, for example) of soy milk and Asian brands (Vitasoy, Mogami) taste very different from each other. Give some new brands a try if you can find them.

          Rotten soy milk definitely smells off, and solifies.

          Here's a funny photo: I bought soy milk at an Asian grocery store. I opened it, poured some, and put the rest in the fridge. It was fine. A few days later, I took the container out of the fridge, tried to pour some, and realized the entire thing had congealed. Something must have been wrong with my fridge or with the soy milk, but to this day I have no idea what caused it. And no, no one got sick.

          But if your soy milk ever does that, you definitely know it's time to toss it.