I put an already-opened bag of kale in the freezer. Safe?

November 15, 2022 7:04 AM

I add kale to my smoothies. Two weeks ago, I bought a big bag of kale from the grocery store and took out some of the kale to make smoothies. I put the (clipped) bag back in the refrigerator for a few days, then put the bag in the freezer so I could save it for the next batch of smoothies (later this week). I believe the kale was put in the freezer before its expiration date. Is this okay/safe?

Reason I ask is because I've seen some reports of kale being tricky to freeze, and they were uncooked. I tend to make a big batch of smoothies that will last me two weeks, then freeze the batches and thaw everyday to drink/eat. The frozen bag of kale is now past its expiration date, but as it is frozen, I believe it would not be a problem.

Thanks for your input! I don't want to waste the kale, as it was a big bag, but want to make sure it'll be safe/okay to add to the next batch of smoothies.

posted by dubious_dude to Food & Drink (9 answers total)

Safe, yes, delicious, maybe not. Kale is tricky to freeze in that it tends to get freezer burnt and gross and dried out. But it won't be unsafe. If you like the way it tastes in your smoothie, you're good to go.

Also you probably don't need to thaw it before you use it.
posted by mskyle at 7:07 AM on November 15, 2022 [3 favorites]

Just a safety note about frozen things for smoothies. While the kale itself may be fine, be careful about what it's being frozen in…bag, tupperware, etc.

Today's PSA brought to you by this morning's smoothie, which contained small pieces of blended plastic from the bottom of the takeaway tub where I stored my frozen bananas — part of the tub bottom clung onto the banana rather than its the rest of its plastic family.
posted by iamkimiam at 7:13 AM on November 15, 2022 [4 favorites]

Kale can't get dangerous, just icky.

If you want to freeze kale, the best thing to do is chop it up then blanch it (boil hard for a minute or two) then freeze it in an ice cube tray – I use one like this to make convenient reusable blocks for later).
posted by zadcat at 7:40 AM on November 15, 2022

I have done this for years and it’s been fine/great. Just pop the bag in the freezer as-is and use as needed. I like the way the kale shreds when frozen, much easier to blend!
posted by stellaluna at 7:52 AM on November 15, 2022 [2 favorites]

Kale can't get dangerous

Kale, like all the leafy greens, can arrive contaminated with e. coli and other pathogens and once opened can get exposed to bacteria in the fridge. That said, as long as OP didn't get sick initially from it and the fridge isn't an overgrown disaster, it's almost certainly fine from a safety perspective.
posted by Candleman at 8:14 AM on November 15, 2022 [2 favorites]

I'm generally a food safety alarmist in these threads -- but you're fine from a safety perspective. Your kale never stayed in the danger zone (40-140F) for long enough to allow significant bacterial growth. It may develop texture, flavor, or appearance issues, though -- freeze/refreeze cycles can burst cell walls, make veggies feel slimier, and create freezer burn. Next time, I'd recommend blending the kale straight out of the freezer -- there's no need to thaw it for a smoothie.
posted by ourobouros at 9:34 AM on November 15, 2022

Response by poster: Would you say the frozen kale (which I don’t plan to thaw) will add a bitterness to my smoothie?
posted by dubious_dude at 1:27 PM on November 15, 2022

Not unless it was bitter when it was fresh. If it tasted good fresh, it should taste the same now.

Freezer burn tends to negatively impact texture and provide the flavor of old freezer, rather than bitterness. After freezing for only two weeks, all should be well.
posted by jenquat at 3:27 PM on November 15, 2022 [1 favorite]

For what it's worth, many grocery stores stock frozen kale for smoothies. If smoothies are your primary use for kale, you could buy a frozen bag in the future instead of worrying about using up a fresh bunch before it goes bad. And it's almost as convenient — as noted above, you don't have to thaw it out before tossing it in the blender.
posted by Johnny Assay at 4:09 AM on November 16, 2022 [2 favorites]