Does a head of lettuce really need to be refrigerated?
At the grocery store here in Germany I saw that lettuce isn't refrigerated. So I brought a head home and it's been in my pantry for 3 days and it seems fine... The English speaking internet says that's not ok, I don't know what the German one says.
Best Answer
It is all due to storage lifetime. Lettuce is particularly perishable, compared to many other vegetables.
You will get a considerably longer storage lifetime if it is refrigerated, rather than kept at room temperature.
According to the USDA:
Storage Conditions: Lettuce should be quickly cooled and maintained as close to 0 °C (32 °F) as possible with 98 to 100% RH. Head types are better adapted to prolong storage than are the other types, but none keep longer than 4 weeks, and about half that time at 5 °C (41 °F). Film liners or individual polyethylene head wraps are desirable for attaining high RH; however they should be perforated or be permeable to maintain a non-injurious atmosphere and to avoid 100% RH on removal from storage. Lettuce is easily damaged by freezing, so all parts of the storage room must be kept above the highest freezing point of lettuce of -0.2 °C (31.6 °F).
They follow up later in the document with this chart showing how lettuce's respiration rate increases with temperature—and of course, once harvested, the lettuce only has so many nutrients available to metabolize:
You can see at warmer temperatures, the lettuce will expire much more quickly.
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Quick Answer about "Does a head of lettuce really need to be refrigerated?"
It is all due to storage lifetime. Lettuce is particularly perishable, compared to many other vegetables. You will get a considerably longer storage lifetime if it is refrigerated, rather than kept at room temperature.Can a head of lettuce be left out of fridge?
You should refrigerate your lettuce, no matter the type, after two hours of sitting out. If you leave your lettuce out for more than two hours, you are risking the growth of harmful bacteria on the leaves.Does a head of iceberg lettuce need to be refrigerated?
Bacteria grow rapidly at temperatures between 40\xb0 F and 140\xb0 F; iceberg lettuce should be discarded if left out for more than 2 hours at room temperature. To maximize the shelf life of iceberg lettuce, refrigerate in a loosely closed plastic bag and do not wash the iceberg lettuce until ready to eat.How long does lettuce last out of the fridge?
Loose-leaf lettuce typically keeps between 7 to 10 days, while head lettuce (e.g., iceberg) keeps for between a week and three weeks. In other words, crisphead lettuce keeps for much longer than its loose-leaf counterpart....How Long Does Lettuce Last?FridgeHead lettuce (iceberg and similar)7 \u2013 21 daysLettuce leavesup to 7 days1 more row•Sep 16, 2021How to store a Lettuce Money Saving Home Hint cheekyricho
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Answer 2
Usually sellers hold the lettuce at room temperature during the hours of sale (to show to buyers) and place them in the refrigerator in the night.
But attention. The supermarkets assemble the heads under plastic films (as said), which retain moisture, and daily keep them anyway in departments "fresh." The small vendors display the salads without protection, but often spray water, to maintain the freshness of the leaves, which otherwise would wilt.
The result is the same of cut flowers placed in a jar with water.
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