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An Amazing Way To Keep Chopped Romaine Lettuce Fresh

Now you can enjoy a salad every day as fast as you can take the lid off. I call it healthy fast food. It’s as easy as opening a bag of chips. Keep reading to find out how to keep chopped or cut romaine lettuce fresh in the fridge.

Updated and republished in March 2020

Vacuum-pack Lettuce to Prolong Freshness-- Jars of vacuum-packed lettuce with a tape measure around them.

Add your dressing and any veggies, nuts or other extras you have on hand. Sit down to eat in less than 3 minutes.

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.

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-packed into a Mason jar and stored in the fridge. It’s easy to do. I promise. The process is not complicated!!

Now I’m a DAILY salad eater, and you can be, too!

3 vacuum-sealed jars of chopped lettuce

What is the secret for making chopped romaine lettuce last longer?

Chopped romaine lettuce will stay crisp and fresh for 7-10 days when vacuum-packed 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.

Vacuum-sealing jars of lettuce with equipment needed to vacuum-pack it.

Six Benefits of Vacuum-Sealing Lettuce:

 #1

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.

#2

Keeps lettuce from turning brown

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.

#3

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.

#4

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.

#5

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.

#6

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.

romaine lettuce leaves

FAQ about Vacuum-Packing Lettuce in Jars:

Can you vacuum-pack lettuce?

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.

Can I vacuum-pack leafy greens, spinach or spring mix?

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.

Can I vacuum-pack other fruits and vegetables along with the lettuce?

You can, but I don’t recommend it. The results are unpredictable and most likely to shorten the time the lettuce will stay fresh. In my experience, sliced carrots will work as well as cabbage. 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.

How long does lettuce stay fresh when vacuum-sealed?

7-10 days on average. The freshness of the lettuce at the time of packing can make a difference.

What do I need to get started?

>Hearts of romaine lettuce (Romaine lettuce work 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!

How long does it take to prepare the jars?

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.

What if I can’t eat a whole quart of vacuum-packed lettuce at once? Will it be ruined once I open it?

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.

Do I really need a vacuum-pack device? I’ve heard rinsing the lettuce in lemon juice or vinegar will help it stay fresh longer.

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!

Any suggestions for other ways to use a vacuum-pack machine?

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.

Why is tearing lettuce with my hands or cutting it with a plastic knife unnecessary with this method?

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.

Can I vacuum-pack lettuce into small-mouth Mason jars?

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.

Do I need a jar attachment for each jar?

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 bricks-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.

Can I reuse the flat canning jar lids and collars?

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.

Why can’t I get the lid to seal on my jar of lettuce:

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.

Why not store clean lettuce in a plastic bag with a paper towel?

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.

Why vacuum-pack my jar of lettuce instead of covering it with a regular screw-on lid?

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.

Can I vacuum-seal lettuce in a plastic bag instead of glass jars?

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.

Which vacuum-pack machine should I buy?

My preference is a portable device that runs on batteries. They are less noisy, take less storage space, and are cheaper.

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.

Where can I find a good deal on vacuum-pack machines?

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

romaine lettuce, salad spinner, large bowl for cut lettuce, Mason jars and a portable vacuum packing device

Gather your equipment.

washing whole lettuce

Leave the lettuce leaves intact. Open head and wash well under running water.

slicing lettuce with a knife

Use a large knife to slice through the lettuce lengthwise at least 4-5 times.

slicing lettuce into small pieces

Slice crosswise to create 1/2 inch or smaller pieces. Place chopped lettuce into lettuce spinner basket.

rinsing lettuce at the sink in a salad spinner basket

Optional: give chopped lettuce in the basket an additional shower before spinning.

putting lid on a salad spinner

Put cleaned and chopped lettuce into the salad spinner.

operating a salad spinner

Put the lid on and spin away.

How do you vacuum-seal lettuce into Mason jars?

dumping spin-dry lettuce into a large bowl
Empty the contents of your salad spinner basket into a large bowl.
a large bowl of chopped romaine lettuce

The bowl is holding nine chopped hearts of romaine lettuce.

stuffing Mason jars with lettuce by hand

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.

checking rims of Mason jars to be sure nothing impedes the seal

Be sure no pieces of lettuce are hanging over the top edge.

placing a flat metal lid on Mason jar

Place a flat lid on top of the jar.

covering jar with a wide-mouth adapter

Cover the jar with the wide-mouth adapter.

vacuum-packing a jar of chopped lettuce with a portable device

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.

vacuum-packing a jar of lettuce with a counter-top full-size device

Alternatively, use a full-size vacuum-pack machine and a hose to connect to the wide-mouth adapter.

putting collar on top of sealed jars of salad

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.

storing jars in the refrigerator

The jars of lettuce must be stored in the refrigerator.

How do I open a vacuum-sealed jar of lettuce?

Opening a jar of vacuum-sealed 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.

pouring a vacuum-sealed romaine lettuce salad into a bowl to eat

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?


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Did you try this recipe and enjoy it? Consider helping other readers (and me) by returning to this post. Leave a rating on the recipe card itself underneath the picture. Although always appreciated, comments aren’t required.

If you have a question or tip to share, please leave it in the regular comments after the recipe so I can answer back. Or, email me privately: paula at saladinajar.com.

Thank you for visiting!
Paula


Vacuum-pack Lettuce to Prolong Freshness

How To Keep Romaine Lettuce Fresh Longer

Yield: 6 servings
Prep Time: 30 minutes
Total Time: 30 minutes

Vacuum-packing fresh-cut or chopped romaine lettuce in Mason jars will keep it fresh up to 10 days. It's "salad in a jar" my way.

Ingredients

  • Fresh romaine lettuce (I use hearts of romaine because the inner leaves last longer than the dark green leaves on a whole head of romaine.) In general, one "heart of romaine" lettuce will fill one quart jar, but that varies.

Instructions

  1. Wash romaine lettuce well, leaving the leaves intact at the base.
  2. Cut lengthwise through the entire head at least 4-5 times.
  3. Now slice crosswise about 3/4 to 1 inch apart according to your preference.
  4. Fill salad spinner and run under the faucet one more time. Spin dry.
  5. Dump into a very large bowl. Fill jars with chopped, spun-dry lettuce. I pack them as tightly as possible.
  6. Seal jars using a wide-mouth jar attachment and a vacuum-pack machine. Screw on rings as insurance to keep lid sealed.
  7. Refrigerate up to 10 days depending on how fresh your lettuce is when you started this process.

Notes

The number of servings or quart jars you end up with depends on how many heads of romaine you use and how compact and large they are. It will also be affected by how tightly you pack the lettuce into the jars.

Nutrition Information:
Yield: 6 Serving Size: 1
Amount Per Serving: Calories: 54Total Fat: 1gSaturated Fat: 0gTrans Fat: 0gUnsaturated Fat: 1gCholesterol: 0mgSodium: 25mgCarbohydrates: 10gFiber: 7gSugar: 4gProtein: 4g

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NN

Tuesday 26th of May 2020

I tried the lettuce in a mason jar and it works like a charm to keep lettuce crispy and lasting longer.

Paula

Tuesday 26th of May 2020

It sure does! Hope you enjoy the convenience now that you did a little prep.

Mary

Friday 5th of July 2019

I’ll have to give this a try; though I’ve lived by a lettuce rule since my 7th grade home school teacher taught it was “never cut lettuce with a knife, it causes it to brown, tear it instead”.

Paula

Friday 5th of July 2019

Mary, thanks for writing. Your teacher's comment about the knife made me smile. I heard the same thing. Obviously, she did not know about vacuum-packing lettuce. It is probably still a good idea if you are making a salad to eat the same day, and it will be a while before you eat the salad. There has to be time for oxidation to happen. Vacuum-packing short-circuits the whole oxidation process.

A Realistic Grocery Budget for a Family of Five : Heart's Content

Sunday 16th of December 2018

[…] 4. The biggest one… waste less food. We throw out quite a bit. Leftovers will need to be eaten. I am always throwing out lettuce. Need to find a way to fix that. Going to try this method. […]

Bonnie Smith

Monday 5th of November 2018

A terrific idea for advance salad prep. I eat and enjoy so much more salad this way. Thanks, Paula!

Suhana Morgan

Tuesday 11th of September 2018

Great house making salad tips. I Appreciate your hard work. It will be helpful for every food lover and housekeeper. By the blessing of almighty, you did not stop writing those beautiful recipes. It helps me more.