Sneak Peek: Learn how to keep romaine lettuce fresh after cutting by vacuum-sealing it into jars 7-10 days in advance. This easy technique transformed me into a DAILY salad eater.
Do you wish you were eating more lettuce salads? I used to feel the same way. Preparing lettuce was too much trouble–especially when I was hungry and ready to eat ASAP.
Now I’m a DAILY salad eater, and you can be, too!
With this amazing system you can enjoy a salad every day as fast as you can take the lid off. I call it healthy fast food. It’s nearly as easy as opening a bag of chips.
How to keep chopped lettuce fresh:
This “salad in a jar” is not the traditional layered salad everybody else makes. It’s also not “canned lettuce” although it may look like it. The lettuce is not heat-processed.
Instead, this fresh, cleaned, and chopped lettuce has been vacuum-sealed into a Mason jar and stored in the fridge. It’s easy to do. I promise. The process is not complicated or expensive!!
Can you vacuum-seal lettuce?
Chopped romaine lettuce will stay crisp and fresh for 7-10 days when vacuum-sealed into a glass Mason jar. It must be stored in the refrigerator.
Let me be clear…
We’re assuming the lettuce is fresh. Don’t pack lettuce that has been hanging around in some warehouse or your fridge for too long.
Old lettuce will shorten the freshness window for a vacuum-packed jar of salad.
Six benefits of vacuum-sealing lettuce to keep it fresh:
Prepare 7-10 jars of ready-to-eat romaine lettuce in 30-45 minutes.
These numbers may vary depending on the freshness of your lettuce and how fast you work.
The vacuum-sealing process removes all the oxygen from inside the jar. Even though the leaves are chopped with a knife, the cut leaves are prevented from oxidizing.
No getting out your chopping board and salad spinner every day to make a salad
Call me lazy, but when I’m famished, I don’t like to take the time to clean, dry, and cut or tear lettuce. Having prepared jars of lettuce salad in the fridge has saved me from eating a lot of junk food.
On the run? Grab a jar and take it with you.
You can eat your salad straight out of the jar. But it’s easier to pour it into a bowl. My lunch bag is big enough to fit a salad bowl if I’m taking my lunch with me.
Save money–especially when you buy romaine lettuce in bulk
Bulk warehouses like Costco or Sam’s are the cheapest place to buy romaine. You can purchase the heads in packages of six.
I’m fond of the artisan romaine sold at Costco. They are slightly more expensive but worth it.
Encourages healthier eating habits
No guarantees on this one. If you eat a healthy salad daily, it could be the start of a new lifestyle. I eat about 7-8 cups of lettuce salad almost every day. Works for me.
Customize your salad according to what’s in the fridge and your current mood.
Add your dressing and any veggies, nuts, or other extras you have on hand AFTER you open the jar and pour it into a bowl. Leftover meat, canned salmon or tuna, nuts, seeds, fresh veggies, or avocado are just a few of the ingredients I keep around make a salad–of-the day in less than 3 minutes.
FAQ about Vacuum-Sealing Lettuce in Jars:
Yes. But it needs to be sturdy lettuce like romaine or radicchio. Iceberg would be my third choice. Napa cabbage is another fave that stores well.
I’ve experimented with all of these. Neither lasted more than 3-4 days. They’re too fragile for vacuum-packing. Although some say it works for them, I can’t recommend it. When it comes to vacuum-sealing, I’m a hearts-of-Romaine girl.
Even though I love romaine, the dark green outer leaves will not last as long as the crispier inner leaves. If I have a lot of dark leaves, I try to eat those jars first.
You can, but I don’t recommend it. The results are unpredictable and will most likely shorten the time the lettuce will stay fresh. In my experience, sliced carrots and cabbage will vacuum-seal pretty well. Avoid adding cucumbers and tomatoes. Beyond that, I can only recommend you experiment.
One of my readers, named Rick, did an experiment adding various veggies to his jars of lettuce. You can read about it here. I wrote a whole post about it if you’re still curious.
7-10 days on average. The freshness of the lettuce at the time of packing can make a difference. As noted earlier, if your romaine includes lots of the outer dark green leaves, those leaves are more delicate and tend to go south first.
>Hearts of romaine lettuce (Romaine lettuce works best because the leaves are sturdy. Spinach and spring mix don’t like to be vacuum-packed.)
>Sharp butcher knife (My favorite is a Wusthoff Santoku knife.)
Large chopping board (wood or plastic)
>Salad spinner (the plastic ones work but the stainless spinner from OXO is better if you are a heavy user)
>Large mixing bowl
>Wide-mouth jar attachment
>Quart-size Mason glass jars with 2-part metal lids
>Full-size vacuum-pack machine or a portable vacuum-device (much cheaper and easier to store)
Note: Everything but the lettuce is reusable!
Actual time to prepare 6-8 jars is 30-45 minutes after you’ve had some practice. Expect to spend a couple of hours the first time or two. Once you get your system down, making the jars goes fast.
You can re-seal the jar after removing part of the lettuce. However, you have compromised the freshness by allowing oxygen to enter the jar. Don’t expect the salad to last as long.
Alternatively, pack your lettuce into 12-ounce pint jars or the 24-ounce straight-sided Mason jars. (paid link) Tip: The smaller the jar, the more difficult they are to seal. Apply more pressure on the lid adapter.
After a reader suggested this, I did a side-by-side experiment. I rinsed lettuce with diluted lemon juice and compared it to vacuum-packed lettuce. The lemon-juice-rinsed-and-cut lettuce began to turn brown after three days. No comparison!
Use your quart jars to vacuum-pack rice, flour, oatmeal, granola, and other dry pantry items. Try storing vacuum-packed stir-fry sauce, barbecue sauce, or salad dressing in the fridge.
Use the plastic vacuum-seal bags for cheese, leftovers, and meat. Food stays in the freezer much longer without freezer burn when vacuum-sealed.
Vacuum-packing removes the oxygen that causes the lettuce to brown when there are cut edges, torn or otherwise. I use a sharp knife so I can chop it fast and in fairly small pieces. Hands and plastic knives are way too slow for me.
Yes, but the wide-mouth jars are much easier to fill, empty, seal, and wash. I HIGHLY recommend the wide-mouth over the small-mouth jars.
No. You only need one. The attachment fits over the opening with a flat lid between the top of the jar and the attachment. Pull the attachment off after sealing. See the video.
Large-mouth jar attachments are available online. I’ve never seen them in a brick-and-mortar store, but readers have reported sightings.
Be sure you buy the large-mouth jar attachment if you have large-mouth jars. Otherwise, buy the small-mouth attachment.
Yes. You can reuse both. When using heat, such as canning, the lids should only be used once. However, vacuum-sealing involves no heat. Unfortunately, both the lids and collars are prone to rust if not completely dried after washing. But they are easy and inexpensive to replace when necessary.
Check to see if there is a stray piece of lettuce on the top of the jar preventing a seal.
Try using two stacked lids instead of one.
Apply some pressure to the adapter holding the lids.
Read this post about 10 tips for getting lids to seal on a Mason jar.
A plastic bag is a good way to store washed lettuce if you leave the lettuce whole and un-chopped or un-torn. It will last longer than buying a bag of salad mix from the store, for sure. However, the romaine still needs to be cut or torn into smaller pieces before eating.
For me, that’s too much trouble when I walk in the door hungry. I like to have everything ready to grab-and-go, with leaves already in small pieces and prepared to pour into a bowl and eat. If you’re not as impatient as I am, then a plastic bag and some paper towels may be sufficient.
Stuffing a jar with chopped lettuce and screwing on the lid is convenient. However, it won’t keep your “salad” fresh any longer than dumping it in a plastic bag like they do at the grocery store. The oxygen must be removed to keep the chopped edges from browning.
Only if your vacuum-pack machine has a pulse feature that allows you to leave some air in the bag. Or you could stop short of vacuuming all the air out before the lettuce is crushed.
The lettuce won’t stay fresh as long as it does in a jar where all the air can be sucked out without smashing the lettuce.
My preference is a portable device that runs on batteries. They are less noisy, take less storage space, and cost less.
If you want a counter-top device, look for a machine that has a port for the attachment. You don’t need all the bells and whistles for this project, but cheap machines may not have a port. So, beware.
Check Tuesday Morning, Ross, eBay, warehouse stores, Walmart, Target and online. Or just ask around. Many people have a vacuum-sealing machine sitting in their cabinets. Some quit using them after they run out of the bags that come with the device.
Portable units are much cheaper and they work great.
How To Prepare Romaine Lettuce for Vacuum-Sealing
Gather your equipment.
Leave the lettuce leaves intact. Open head and wash well under running water.
Use a large knife to slice through the lettuce lengthwise at least 4-5 times.
Slice crosswise to create 1/2 inch or smaller pieces. Place chopped lettuce into lettuce spinner basket.
Optional: give chopped lettuce in the basket an additional shower before spinning.
Put cleaned and chopped lettuce into the salad spinner.
Put the lid on and spin away.
How do you vacuum-seal lettuce into Mason jars?
The bowl is holding nine chopped hearts of romaine lettuce.
Stuff jars full of lettuce. I pack mine tightly. You should pack only as much as you will eat in one sitting. You can reseal the jar, but the lettuce will not be as good the next time around.
Be sure no pieces of lettuce are hanging over the top edge.
Place a flat lid on top of the jar.
Cover the jar with the wide-mouth adapter.
Use a handheld vacuum-pack device to seal jars. Cover the hole on the adapter with the suction cup on the vacuum device. If you have trouble, see this post about sealing questions and answers.
Alternatively, use a full-size vacuum-pack machine and a hose to connect to the wide-mouth adapter.
Seal the jar and remove the wide-mouth adapter. Screw a metal collar on top of the flat lid. The collar will help preserve the seal.
The jars of lettuce must be stored in the refrigerator.
How do I open a vacuum-sealed jar of lettuce?
Pry off the lid with a can opener (as pictured above) or use your fingers. Empty your jar of lettuce into a bowl or onto a plate. Add whatever extras you want.
NOTE: I often add other varieties of lettuce such as ready-to-eat spinach, arugula, or spring mix when I’m getting ready to eat my salad. Since this lettuce is ready-to-eat straight from the store, it doesn’t add any time. Unfortunately, these types of lettuce are unpredictable when vacuum-packed.
Enjoy the good feeling that comes with eating healthy vegetables!
An important safety reminder
Wash your lettuce thoroughly and keep refrigerated at all times for safety’s sake.
Looking for more information?
Did you enjoy this recipe? If so, you can help others and myself by leaving a 5-star 🤩 rating in the recipe below. No comments required.
Hope to see you again soon!
p.s. If you have any questions or suggestions, you can email me privately: paula at saladinajar.com.