These vegetables, which fall under the broader category of salad greens, are typically served raw, seasoned, and tossed with other salad ingredients. But different kinds of lettuce may contribute a lot of texture and taste to whatever you’re preparing, whether you use them raw or cooked. But is it possible to extend the shelf life of lettuce?
Did you know there are only 15 calories in 100 grams (3.5 ounces) of lettuce? Vitamin A (in the form of carotenoids), vitamin K, folate, and molybdenum are all abundant in lettuce. Additionally, dietary fiber, manganese, potassium, biotin, vitamin B1, copper, iron, and vitamin C are abundant in this food. Additionally, it is a good source of vitamin B6, pantothenic acid, phosphorus, chrome, magnesium, and omega-3 fatty acids.
Lettuce’s many health advantages include lower cholesterol levels, improved heart and brain health, improved immunity, regular sleep, reduced anxiety, benefits for skin care, improved vision, reduced inflammation, protection against anemia, assistance with weight reduction, and cancer prevention.
This article explores lettuce and how it can be preserved in the fridge for longer than a few days. We answer many frequently asked questions providing factual information to extend your culinary horizons.
Let’s get into it.
Does lettuce expire?
Yes, Lettuce is highly perishable, and from the moment it is harvested, it is starting to degrade.
But are some lettuce varieties hardier than others? According to the USDA, Romaine lettuce will last longer than, say, a butter lettuce with fragile, tender leaves.
But there is a whole industry driving forward proposals for extending the life of lettuce, and retailers and farmers are sending something like approximately 30% of this vegetable to landfills each year due to spoilage.
According to the University of California at Davis, lettuce has a 21-day shelf life when kept at 32°F. The shelf-life is approximately 14 days at 41°F.
So why does lettuce spoil so fast? Ethylene gas is the answer. When lettuce is harvested and starts to degrade, it releases small amounts of ethylene gas. (it is bad for all veggies) and of course, the lettuce deteriorates faster.
If the lettuce is damaged in any way, lettuce will increase its ethylene production, causing the lettuce to wilt and eventually turn to mush within four or five days.
Does lettuce need to be refrigerated?
Yes. If you harvest your own lettuce, leave it in the ground for as long as possible before it goes to seed.
Once the lettuce is harvested, there is no need to wash it unless you have a clue. It may be full of slugs that are chowing down on your favorite salad leaves.
Place the lettuce in a polythene or paper bag and place the lettuce in the salad crisper. If the fridge is at around 32℉ and the head of lettuce is fresh and in good condition, it should last for three weeks.
If the fridge is at 40℉, the lettuce head will last for two weeks. Clearly, temperature and the life of your lettuce go hand in hand.
If you have leftover lettuce from your salad, place it in a Ziploc bag, we will get into some top tips for extending the life of the lettuce later in the article.
Does lettuce have to be covered in the fridge?
Yes. Store fresh and leftover lettuce in a Ziploc-style bag. It will keep the lettuce fresher for longer. If you store fruits in the fridge, such as apples and bananas, it’s better to keep the lettuce away from them.
Lettuce releases ethylene gas in low amounts, and fruits emit the gas in more significant amounts. When salad leaves are exposed to ethylene gas, they will decay at a much faster rate. Covering does offer some protection to the salad leaves.
Can you put warm lettuce in the fridge?
It is not advisable.
Lettuce is used a lot in cooking. It can be grilled and used in soups and spring rolls, just to mention a few cooking applications.
You should always avoid placing hot food or warm food in the fridge. It’s bad housekeeping. Placing warm lettuce in the fridge could cause a bigger problem than you might have imagined.
Your fridge temperature will be 40℉ -18℃ or a little lower. Placing warm lettuce in the fridge will elevate its temperature while it radiates heat.
Your fridge may not be as efficient as you might have thought at removing heat. Most fridges take hours to come to 40℉ after being switched on after cleaning.
So, what’s the big deal? The big deal is that food sitting at a temperature of 40-140℉ is in the food danger zone. It’s not just your lettuce. It is the contents of the entire fridge.
Above 40℉-18℃ bacterial growth on perishable foods will accelerate exponentially. It should be discarded if the food remains at an elevated temperature above 40℉-18℃ for just two hours.
Seems harsh? According to the USDA, after two hours in the food danger zone, perishable foods contain enough bacteria to cause food poisoning.
Furthermore, the lettuce should be covered in the fridge so there will be no condensation!
How long can warm-cooked lettuce sit out?
Two hours. It’s not a long time, and when sitting around chatting with friends and drinking tea or coffee, the time flies, but the truth is lettuce will become contaminated with bacteria and, after just two hours, could make you sick if eaten.
Remember the food danger zone? According to the USDA, perishable goods sitting out for two hours should be discarded, and the bacteria growth on the food has multiplied rapidly, making the food unfit for consumption.
How long does lettuce last in the fridge?
A few factors will determine the shelf life of a head of lettuce in the fridge.
- Is the lettuce fresh? Does it look fresh if you bought the lettuce from the grocery store? Are the leaves wilting? Are there any brown marks?
- How is the lettuce packaged?
- How cold is your fridge?
If your lettuce is fresh, has no signs of damage, and is wrapped in an airtight container, it could last for three weeks in the fridge if the fridge is 32℉ and two weeks at 40℉.
Outside of these parameters, the lettuce may only last 7 to 10 days stored in the crisper.
Does frozen lettuce go bad?
It depends. Lettuce is fragile and full of water. As soon as the lettuce leaves freeze, the growth of ice crystals in the leaves structure crushes the leaves to mush. After a very short time in the freezer, the lettuce would be ready for the garbage.
However, some varieties of lettuce can be frozen, such as the lettuce with thicker leaves like Cos and Boston, and even Romaine lettuce can be frozen.
Chop the leaves and place them in a Ziploc bag, remove the air and place them in the freezer. The taste is not going to be the same as fresh, but they will nevertheless freeze and be usable.
How to make lettuce last longer in the fridge?
It has already been established that the shelf life of lettuce depends on the fridge’s temperature, so keep your fridge closer to 32℉ to maximize the life of the salad leaves and store them in the crisper.
- Buy the freshest and greenest looking lettuce at the grocery store, withered leaves or brown blemishes, and signs that the lettuce has been exposed to ethylene gas and is decaying.
- Keep your lettuce in the original container from the grocery store. They have been packed for optimal shelf life. If the packaging has been broken, replace the packaging with a Ziploc bag.
- Don’t cut the root base away. Snap the lettuce leaves off from the base. This will enable the lettuce to retain moisture.
- Reduce exposure to ethylene, and never store lettuce with fruits that release ethylene gas, such as bananas and apples. Ethylene gas reduces the shelf life of lettuce.
Keep your lettuce for longer than three weeks.
- Break the leaves of the lettuce from the head and place them in a Ziploc-type bag. Once the bag is almost full seal, the bag leaves enough space to insert a straw. With the straw inserted, physically suck the air from the Ziploc bag. When the leaves are compressed in this rudimentary vacuum sealing method, seal the bag tight.
The lack of oxygen in the Ziploc will extend the shelf life of your lettuce up to 4 or even.
Even though everyone thinks lettuce has a short shelf life, it’s not entirely true, and lettuce leaves that are fresh and stirred at the correct temperature can last for weeks in the fridge.
Lettuce can be a forgotten vegetable. It’s bought and placed in the salad tray, crushed with other veggies, and is expected to be pristine when needed.
Lettuce is fragile, but when stored at the correct temperature and sealed correctly, the shelf life increases to a more acceptable level.