Opened Bag Expiration?

1- How long can I keep my opened bag for ?
2- Should I put the opened bag in the refrigerator or it’s not needed ?

I want to mix half a bag every 2 days approximately since I only use a quarter per day at the moment.
After searching many keywords, their is no result with that information on the forum.

Thanks in advance for any feedback, much appreciated !


I think this only has common-sense answers. If you open a bag, make sure not to get the contents wet. Seal the bags somehow. If you are keeping them just a few days, I don’t think there is anything to worry about. You don’t need to refrigerate the bags for that short a time unless it makes you feel safer as a defense against roaming creatures.


I’d second the comment about “roaming creatures” and keep your bag in the refrigerator. Open bags of flour-type products are an invitation to pantry moths, which can be a real nightmare if you get them.

Excellent suggestion.
But the technical part of this answer is not “common sense” to me.

1- How long can I keep my opened bag for ?

As in, what is the suggested number of days ?
For the mixed version, I found many answers and all say max 3 days. One pushed to 4 days and spit it out after one gulp.
What about opened and resealed bag now ?


I am curious about this too, because I add powdered flavoring and so I like to mix up 2-3 days worth at a time in a reclaimed Muscle Milk canister so that I can easily prepare it a meal at a time. The canister is opaque and I keep it in a cabinet, so I don’t think light is an issue, but I’d hate to think that I was losing nutrition due to oxidation.

I think we need to ask the Great and Powerful @Soylent

This question also has implications for the hypothetical large-scale packaging that we have discussed on other threads. If the shelf-life is relatively short, that means that having a scoopable tub with a week or month’s worth of Soylent for preparing individual meals is not a tenable idea. I prepared three individual meals in Ziploc bags, with Splenda and PB2 added, about two months ago and put them aside for travel or whatever. I wonder if they are still good.

I have pushed it to 5 days and never spit it out. It was refrigerated and it tasted fine to me. There might have been some degradation to the nutrients, but I could not discern anything that would have hurt me.
(I usually consume within 48 hours; It was just a special circumstance.)

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My opinion is that as long as the stuff is dry, keeping it for three or four days after having opened the package is unlikely to cause a problem, even if you have added other dry stuff. If you add something wet or moist, I wouldn’t trust it beyond the three-day refrigerated max that is the usual limit for Soylent that has been combined with water.

Months ago I was seeing “7 days dry” being tossed around as the time before the nutrients started degrading noticeable due to exposure to air. I’ve no idea how accurate it was, but I’d like to know as well. I mix in other stuff as well and it would be convenient if I could mix up a week’s worth at a time.

I don’t think this is a life-or-death question. I would feel perfectly free to test the limits. Seven days sounds reasonable.

Sadly, humans aren’t equipped with internal nutrient meters to answer this call for data, so I’d still like to hear from @Soylent on the matter.


Yeah, my concern isn’t so much for safety, I eat plenty of stuff well past “best by” dates; my concern is more about nutrition, one of the many reasons I got interested in the first place was the predictability/uniformity this allows.


Pretty much this. I’ve suggested to RL that they offer Soylent in a week-size plastic canister, and my answer was that there are many confounding factors which require intensive cross-examination before they can make such an offering. This could mean that they don’t think the nutrients will remain stable for a week in a large space, or it could be PR-talk for “we don’t know.”

I have no problem using my own container, so I want to know the consequences of mixing up a week at a time.

From the “I am Rob AMA” on reddit three weeks ago,

“Our label lists a minimum level at which the nutrients are to be found at after our shelf life, which is 2 years. This means that in a fresh pouch of soylent the actual vitamin levels are higher than what is on the label.”

So, even with nutrient degradation from the pouch being opened for days, I doubt the nutrients degrade to less than the values listed on the label.


I would appreciate whatever insight is available (probably none) about whether the Ziplocs I filled with Soylent and flavoring two months ago are still good. I am suddenly afraid to experiment on myself with them.

If the ziplocks seem properly sealed, I would taste some Soylent to see if it seems to taste ok. That’s the way I think, and I’m still alive.


Have you dared to experiment since your post ?

Funny you should ask. I win bad father of the year award for this, but my son drank some, not me. He was warned against it, but likes the peanut butter flavor that was mixed into the Ziplocs and wanted to have a quick meal before he went out with his friends. As of this month, he lives on his own and hasn’t figured out the cooking thing yet, so he volunteered to try it. He liked it fine. He is still alive and has no obvious health effects, and he took the other two Ziplocs plus a box of Soylent, so I’d say we have confirmation: Soylent plus Splenda plus PB2 sealed in a Ziploc can stay good for over two months. I think we also have a new Soylent customer, now that he is away from his mother’s evil “Soylent is gross, you have to cook” influence. (Note that his mother has never tried Soylent…)


This. I am filled with rage that my uninformed spouse refuses to let me educate her and dismisses Soylent as weird chemical shit.


FWIW, I have been DIYing for a long time, and the last time I mixed a batch I made a 4 month supply, of which I am now nearing the end, and it’s still fine from all that I can tell. Also, many of my individual ingredients have been open for a much longer time without any noticeable issue… maybe I’ll keel over tomorrow though.

I would be suprised if opened Soylent spoils in short order. So long as it’s properly sealed and stored it should be a non issue.