# How can i prevent shredded lettuce from spoiling **URL:** \ **Category:** Factual Questions\ **Created:** [April 23, 2003, 11:21pm UTC](https://boards.straightdope.com/t/how-can-i-prevent-shredded-lettuce-from-spoiling/170712 "2003-04-23T23:21:23Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![The\_Calculus\_of\_Logic](https://avatars.discourse-cdn.com/v4/letter/t/aeb1de/32.png) [@The\_Calculus\_of\_Logic](https://boards.straightdope.com/u/The_Calculus_of_Logic)\ **Post date:** [April 23, 2003, 11:21pm UTC](https://boards.straightdope.com/t/how-can-i-prevent-shredded-lettuce-from-spoiling/170712/1 "2003-04-23T23:21:23Z")
The best i can come up with is putting paper towels in the bag with the lettuce and putting it in an air tight container. But even that doesn’t work too well. What else is there to do. ---
**Author:** ![samclem](https://avatars.discourse-cdn.com/v4/letter/s/a9a28c/32.png) [@samclem](https://boards.straightdope.com/u/samclem)\ **Post date:** [April 23, 2003, 11:32pm UTC](https://boards.straightdope.com/t/how-can-i-prevent-shredded-lettuce-from-spoiling/170712/2 "2003-04-23T23:32:37Z")
I have no proof, but I would assume that the act of shredding creates such an increase in surface area that you can only keep it for a short period of time. That is, without preservatives. Why do you need to shred it and then keep it? For how long? ---
**Author:** ![Zenster](https://avatars.discourse-cdn.com/v4/letter/z/cdc98d/32.png) [@Zenster](https://boards.straightdope.com/u/Zenster)\ **Post date:** [April 24, 2003, 12:18am UTC](https://boards.straightdope.com/t/how-can-i-prevent-shredded-lettuce-from-spoiling/170712/3 "2003-04-24T00:18:12Z")
Produce suppliers now seal packaged bean sprouts and leafy greens in an argon (inert gas) atmosphere. While difficult to implement at home it is highly successful in retarding spoilage. Are you buying your lettuce pre-shredded? If so, why? You are being charged many dollars per pound for saving you 15-30 seconds of time and energy. Try purchasing a full head of lettuce. Use a sharp long-bladed knife to cut off thin cross-sections of the lettuce (perpendicular to the stalks). These will fall apart into very nice shreds. The remaining intact head of lettuce will have a shelf life that is nearly ten times longer than its pre-shredded cousin. Air tight containers are not helping you either. They permit condensation of exuded moisture to collect upon the lettuce, accelerating its spoilage. Try wrapping your lettuce in just the paper towels only. You could put them in a paper bag if you wanted. This might help a little. As pointed out by **samclem** , increasing the surface area (and cut membranes) of your lettuce by an order of magnitude is not doing you any favors. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [April 24, 2003, 12:31am UTC](https://boards.straightdope.com/t/how-can-i-prevent-shredded-lettuce-from-spoiling/170712/4 "2003-04-24T00:31:12Z")
Add a teaspoon of lemon juice to the container and shake to distribute over the leaves. The juice acts as an antioxidant and slows browning. [Linkydinkydoo](http://www.google.com/search?as_q=lettuce+browning+antioxidant&num=10&hl=en&ie=ISO-8859-1&btnG=Google+Search&as_epq=lemon+juice&as_oq=&as_eq=&lr=&as_ft=i&as_filetype=&as_qdr=all&as_occt=any&as_dt=i&as_sitesearch=&safe=off) for the skeptics. ---
**Author:** ![FranticMad](https://avatars.discourse-cdn.com/v4/letter/f/c68b51/32.png) [@FranticMad](https://boards.straightdope.com/u/FranticMad)\ **Post date:** [April 24, 2003, 12:36am UTC](https://boards.straightdope.com/t/how-can-i-prevent-shredded-lettuce-from-spoiling/170712/5 "2003-04-24T00:36:52Z")
My grandmother-in-law wraps every leaf in paper towels, and it seems to work. I know this doesn’t answer your question about shredded lettuce, but Zenster had an interesting idea about that. Otherwise, consider living better through [chemistry](http://www.fao.org/docrep/V5030E/V5030E0d.htm). ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [April 24, 2003, 1:17am UTC](https://boards.straightdope.com/t/how-can-i-prevent-shredded-lettuce-from-spoiling/170712/6 "2003-04-24T01:17:36Z")
I have always heard that cutting lettuce rather than tearing it hastens browning. I have never tested this scientifically. However, the lemon juice idea is a good one, works for apples. When it comes down to it, lettuce is fairly perishable and can’t be expected to last too long even under the best of conditions. ---
**Author:** ![The\_Calculus\_of\_Logic](https://avatars.discourse-cdn.com/v4/letter/t/aeb1de/32.png) [@The\_Calculus\_of\_Logic](https://boards.straightdope.com/u/The_Calculus_of_Logic)\ **Post date:** [April 24, 2003, 2:59am UTC](https://boards.straightdope.com/t/how-can-i-prevent-shredded-lettuce-from-spoiling/170712/7 "2003-04-24T02:59:41Z")
> [@](#): > > \*Originally posted by samclem \* > \*\* > Why do you need to shred it and then keep it? For how long? \*\* I buy it shredded. ---
**Author:** ![handy](https://avatars.discourse-cdn.com/v4/letter/h/b5a626/32.png) [@handy](https://boards.straightdope.com/u/handy)\ **Post date:** [April 24, 2003, 3:40pm UTC](https://boards.straightdope.com/t/how-can-i-prevent-shredded-lettuce-from-spoiling/170712/8 "2003-04-24T15:40:06Z")
"Are you buying your lettuce pre-shredded? " I do & it keeps for weeks if I don’t open it. ---
**Author:** ![Zazie](https://avatars.discourse-cdn.com/v4/letter/z/6f9a4e/32.png) [@Zazie](https://boards.straightdope.com/u/Zazie)\ **Post date:** [April 24, 2003, 3:48pm UTC](https://boards.straightdope.com/t/how-can-i-prevent-shredded-lettuce-from-spoiling/170712/9 "2003-04-24T15:48:46Z")
Make sure it is dry, and wrap it in a (clean!) rag and then put the whole thing in a plastic bag in your fridge. It works for me. ---
**Author:** ![voguevixen](https://avatars.discourse-cdn.com/v4/letter/v/b5ac83/32.png) [@voguevixen](https://boards.straightdope.com/u/voguevixen)\ **Post date:** [April 24, 2003, 3:49pm UTC](https://boards.straightdope.com/t/how-can-i-prevent-shredded-lettuce-from-spoiling/170712/10 "2003-04-24T15:49:56Z")
This isn’t very cost effective if you don’t already have one, but I store our leaf lettuce in one of the canisters that comes with the Tilia FoodSaver vacuum sealer. Only my husband eats lettuce in our house, so we were losing about a half a head a week to the compost pile. After we got the vacuum sealer I can use up the whole head and it lasts about 2 weeks. I don’t know how well it will work for shredded, but I do usually just separate the leaves then cram them in all together, if that info helps at all. ---
**Author:** ![blue\_poop](https://avatars.discourse-cdn.com/v4/letter/b/c68b51/32.png) [@blue\_poop](https://boards.straightdope.com/u/blue_poop)\ **Post date:** [April 24, 2003, 10:19pm UTC](https://boards.straightdope.com/t/how-can-i-prevent-shredded-lettuce-from-spoiling/170712/11 "2003-04-24T22:19:58Z")
Use a plastic knife. You can buy them as they are specifically made for cutting the delish veggie your speaking about! I don’t know why but apparently using a metal knife causes the lettuce to brown more quickly. good luck! ---
**Author:** ![UncleBill](https://avatars.discourse-cdn.com/v4/letter/u/d26b3c/32.png) [@UncleBill](https://boards.straightdope.com/u/UncleBill)\ **Post date:** [April 24, 2003, 11:53pm UTC](https://boards.straightdope.com/t/how-can-i-prevent-shredded-lettuce-from-spoiling/170712/12 "2003-04-24T23:53:34Z")
Although plants take in CO[sub]2[/sub] and give off O[sub]2[/sub] during life, the process can reverse after death, with the sugars reacting with oxygen to produce water and CO[sub]2[/sub]. Lettuce is one of the more slow products in its respiration rate. Shredded respires faster than leaf, for the reasons mentioned above. Wounds and greater exposed surface area contribute greatly, as does temperature. From the [International Fresh-Cut Produce Association:](http://www.fresh-cuts.org/pc_lettuce.html) > [@](#): > > **Raw Product Storage and Handling:** Lettuce should be precooled to 34 F soon after harvest and stored at 32F and 98 to 100% relative humidity for retention of quality and shelf life. Because lettuce is so fragile, it is handled as little as possible. Most fresh market lettuce is hand cut and trimmed, and placed in cardboard cartons in the field. It is then trucked to a central area for vacuum cooling. In a few areas it is not vacuum cooled, but placed in a cooler for temporary holding until trucked to market. Whole lettuce is usually not washed before it gets to the store, but some may be hydrocooled or hydro-vacuum cooled. > > **Respiration Rate and Packaging Information:** Leaf lettuce respires at about twice the rate of head lettuce. For head lettuce, at 0(C(32(F) the respiration rate is 6-17mg CO2/kg/hr. At 4-5(C(40-41 (F) the respiration rate is 13-20 mg CO2/kg/hr.For leaf lettuce, at 0(C(32(F) the respiration rate is 19-27mg CO2/kg/hr. At 4-5(C(40-41 (F) the respiration rate is 24-35 mg CO2/kg/hr. Keep it VERY cold, and VERY moist. But not below 31 degF, where chill problems can occur.