Difference between revisions of "Keep Lettuce Fresh"

#Remove the core from crisp lettuce heads. Iceberg, romaine, and other lettuce with a stiff core last longer when this core is removed.<ref name="rf1">http://www.cooksillustrated.com/how_tos/5633-lettuce-storage</ref> Cut out the core with a knife, or pound the stem against a cutting board firmly, then twist the stem to remove the core by hand.<ref name="rf2">http://everydaygoodthinking.com/2013/06/21/how-to-clean-and-store-lettuce/</ref>

#Wrap the lettuce in paper towels. Sandwich the head of lettuce — or loose leaves in single layers — between two soft, absorbent paper towels. These will absorb excess water but keep the lettuce in the moist conditions it prefers.<ref name="rf3">http://msue.anr.msu.edu/news/refrigerator_humidity_effects_on_produce_quality</ref>

#*If the lettuce feels dry, dampen the paper towels.<ref name="rf1" />

#*If the lettuce is wet enough to soak the towels, squeeze them out and wrap the lettuce again in the same, moist paper towels.<ref name="rf4">http://www.stellaskitchen.com/howtokeeplettucefresh.html</ref>

#Store in a plastic container. This can be a zip-locked bag, hard plastic container, or even a salad spinner. If using a bag, press out some of the air before sealing, without bruising the leaves. If using a hard container, fill it at least halfway with leaves.<ref name="rf5">http://extension.oregonstate.edu/fch/sites/default/files/documents/pnw_612_storingfoodforsafetyquality.pdf</ref> The more air in the container, the faster you'll get brown edges.<ref name="rf6">http://www.salad-in-a-jar.com/skinny-secrets/the-lettuce-experiment-and-a-giveaway</ref>

#*If you press out all the air and seal the container completely, the lettuce may develop off flavors due to poor respiration.<ref name="rf7">http://www.fao.org/docrep/t0073e/t0073e02.htm</ref> Leaving a little air or cracking the container slightly may be a better idea, especially with leaf lettuce or a fridge that's on the warm side.<ref name="rf8">http://www.ba.ars.usda.gov/hb66/lettuce.pdf</ref>

#Place in the crisper drawer. This is the coldest part of your fridge, which is ideal for leafy greens. Most grocery store lettuce should last 3-7 days here, depending on freshness, while iceberg may last up to two weeks.<ref name="rf5" /> Fresh lettuce from your garden or a farm stand may last longer.

#*Do not store in the same drawer as apples, pears, or tomatoes, which release high amounts of ethylene gas that can cause spoilage.<ref name="rf8" />

#Watch the container. If water is running down the sides of the container, lower your fridge's humidity settings or open the crisper drawer's air vents wider. (You may also want to drain out the excess water.) If you see ice in the crisper drawer or on the leaves, raise your fridge's temperature.<ref name="rf4" />

#Exhale into your own personal cut lettuce supply. Carbon dioxide can reduce browning and increase shelf life in cut lettuce.<ref name="rf8" /> One easy way to add CO₂ is to exhale a small amount into the bag of lettuce, then seal it.<ref name="rf9">http://www.thekitchn.com/how-dorie-greenspan-keeps-her-139271</ref> For sanitary reasons, do this only with lettuce you plan to eat personally.

#Add a stronger carbon dioxide source. This clever way to add carbon dioxide can increase your lettuce's lifespan by five extra days, in the best case scenario. Here's how to set it up:<ref name="rf10">http://www.cooksillustrated.com/how_tos/6523-a-safer-way-to-keep-greens-fresh-with-carbon-dioxide</ref>

#Vacuum seal crisp lettuce in a glass jar. If you have a vacuum-packing machine, you can use it on a jar of iceberg lettuce to keep it fresh for up to two weeks.<ref name="rf11">http://readynutrition.com/resources/vacuum-sealing-can-be-hazardous-to-your-health_12022013/</ref> Romaine lettuce typically lasts a week when vacuum sealed. This does not work well with butter lettuce and other tender leaves.<ref name="rf12">http://www.salad-in-a-jar.com/family-recipes/can-i-add-other-foods-to-my-vacuum-packed-jars-of-salad</ref>

#*You can imitate a vacuum packing machine with a much cheaper (but less effective) hand pump. Punch a hole through the jar lid with a thumbtack, cover it with electrical tape, and pump air out through the tape.<ref name="rf13">http://www.salad-in-a-jar.com/family-recipes/how-to-vacuum-pack-salad-in-a-jar-for-less-than-6-plus-a-video</ref>

#*This will not work with a plastic bag of lettuce, as the leaves will be crushed in the vacuum.<ref name="rf14">http://www.salad-in-a-jar.com/skinny-secrets/salad-in-a-jar</ref>

*Lettuce wilts when it loses water. If your lettuce wilts, restore it by placing the leaves in a bowl of ice water for 30 minutes.<ref name="rf15">http://www.cooksillustrated.com/how_tos/6648-unwilting-lettuce</ref>

*Washing "pre-washed" lettuce does not increase safety. In fact, you're more likely to introduce new contaminants from your kitchen than you are to make the letter cleaner.<ref name="rf16">http://www.cooksillustrated.com/how_tos/5618-rewashing-prewashed-lettuce</ref> For the same reason, do not wash unwashed lettuce until you are about to use it, so any introduced bacteria do not have time to grow.

*Be extra careful not to contaminate the lettuce when vacuum-sealing, as the pathogens that survive in a vacuum do not leave visible signs.<ref name="rf11" />