Senior man's hands close up; cutting lemon in preparing raw fish

When life gives you lemons, the saying tells you to make lemonade. But what about when life gives you bad lemons? Do you just throw them away? It doesn’t seem right when there’s still some life left in the lemons that have started to go bad.

For example, the lemons may still be loaded with their health benefits, such as aiding in digestion and helping to detoxify the body. The uses for this citrus fruit range from inclusion as a cooking and baking ingredient to adding flavor to boring beverages to creating DIY household cleaners.

So before you toss that lemon out for good, make sure you know how to tell if it has gone bad.

Shelf Life of Lemons

Lemons have a pretty long shelf life, as long as you store them properly. When refrigerated in a plastic bag, lemons will keep for around three to four weeks. This time is shortened to about a week when they're stored at room temperature.

You can freeze whole lemons, slice them before freeing or freeze just the juice. When you freeze a whole lemon, it will last for about three to four months.

Freshly squeezed lemon juice only stays fresh for a few days in the fridge. However, commercially packaged lemon juice can keep for months in the fridge when opened, since it contains preservatives. Leave it unopened, and this juice will last well over a year.

Can You Use Lemons That Are Going Bad?

People buy lemons for many purposes, including health benefits. The rich amount of vitamin C in lemons can help reduce the risk of heart disease and stroke. They may also help those suffering from anemia. So the benefits of lemon are definitely more sweet than sour.

You can use both fresh lemons and those that may have just started going bad for many household-cleaning and cooking methods. However, when you see mold on your lemon it's time to toss it out.

Especially when you're using it for food or drinks, only use lemons that are either fresh or that have only started going bad – for example, if there is a slightly mushy spot or a slight discoloration on the skin.

Household and Cooking Uses for Lemons Starting to Go Bad

  1. Use the skin for zesting: When recipes call for lemon zest, you can still use the skin of the lemon as long as it's still yellow and firm, and not discolored. The zest works great as a topping for desserts and cocktails.

  2. Save the lemon juice for lemon water: You can use your hands or a lemon juicer to squeeze the juice out of a lemon. You can then use this juice for a few different purposes, such as making lemonade at a later date or creating lemon iced cubes to add to water for a refreshing taste.

  3. Make a DIY cleaner: The acid in lemons acts as a natural bleach, thanks to its antibacterial and antiseptic properties. This makes for a great DIY cleaner to use around the house. Simply add the old lemon juice to a spray bottle filled with vinegar (another great cleaning agent). Spritz around the house in places that need it most such as the garbage disposal, on countertops and on tough stains. 

Why Did My Lemon Turn Green?

The are two reasons that could explain why your lemon turned green. One is good and the other – not so good.

Starting with the good: If the lemon has taken on a bright green color (almost like a lime), then this is likely because of temperature changes, not as a sign that it has gone bad.

Be on the lookout for brown spots, though, as they indicate that a lemon is going bad.

As for the not-so-good: A dark green coating with a dusty texture on the lemon is likely mold. If you see any mold, discard the lemon.

Which Types of Mold Affect Lemons and Other Citrus Fruits?

Mold doesn’t discriminate – it can happen to any of the citrus fruits out there, including grapefruit, limes and, of course, lemons. If mold starts to grow, forget about using your lemon as an ingredient for dinner or as a water flavoring. Instead, the fruit needs to be tossed out.

The type of mold that affects citrus fruits the most are penicillium, alternaria and cladosporium; penicillium is the most common. Less common molds on citrus fruits include trichoderma, geotrichum and rhizopus.

When you see a green dust on your lemon, this is penicillium. Its spoers appear like a fine powder and can even be So remember – if you see mold, discard, discard, discard.

Can Eating Mold Make You Sick?

You can get sick from eating mold, however, it does depend on how much you consume. If it's very little, you might not experience any symptoms, but if it's a large amount, you might experience side effects such as stomach pain, allergic reactions and respiratory problems.

Keep in mind that mold can even produce two poisonous substances: mycotoxins and aflatoxin. Mycotoxins are typically produced from mold found on grain products, but it can be found on fruits and vegetables as well.

Aflatoxin, is a potentially carcinogenic substance produced by fungi found on different foods, especially corn and peanuts.

There's a Moldy Orange in My Bag

Once an orange is picked from the tree, it has around three weeks at room temperature before it goes bad. So you need to account for the fact that the oranges were probably in the grocery store for about a week before you bought them. This lowers the shelf life to two weeks. If you store them in the fridge, you have up to two months.

An orange that has gone bad is soft at first. It then develops a white mold that will eventually turn green. A sour smell is another indication. Like other citrus fruits, oranges can grow enicillium digitatum and penicillium italicum molds.

When you find a spoiled orange in a bag, this spells trouble because the mold can spread like a virus. Remove the affected orange right away. You may also want to wash the others to get rid of any mold particles.

What Can I Do With a Lot of Lemons?

Although you can still take one lemon that's just started going bad and add the juice to drinks or household cleaners, you'll need to use them quickly when you have a surplus.

You can use them for all sorts of things, such as baking, making homemade lemon curd, and making a fresh batch of lemonade – or put the juice in a spray bottle to clean up after baking. Some beloved lemon recipes to consider include lemon meringue pie, lemon loaf, lemon chicken and lemon baked cod.