Lemons are an incredibly versatile fruit. You can use them in a range of dishes, and sometimes even to clean your house.
But, would you know how to tell if a lemon is bad, or what will happen to you if you eat a bad lemon?
This article will cover everything to look out for if your lemon is going off and other common questions.
How to Tell if a Lemon is Bad
It doesn’t get any better than tugging a fresh lemon from the tree. They’re bright yellow from ripening in the sunshine, are firm and when lightly squeezed will coat your fingers in natural citrus oils.
When it comes to buying them from a supermarket, there are a few things to consider, as many lemons are imported and stored for long periods.
So before you make your next citrus purchase, make sure you’re getting the freshest lemons possible! Here are some tips to spot quality produce:
Appearance
Lemons should be bright yellow, not a pale or buttery yellow. Think school bus yellow and you’re on the right track.
Pale yellow lemons have been picked too early, and will never fully ripen once picked. This means they will not be as flavourful as their riper bright yellow cousins.
The skin should also look tight, with no signs of wrinkles or cracks, no great big dimples or twists and gnarls. Lemons that are deformed are a product of poor farming practices and can range from insufficient watering, inappropriate fertiliser application, or pest/growth issues.
Whilst these lemons are perfectly safe to eat, they may not have the best flavour, and can be problematic for certain cooking practices, i.e. zesting or juicing.
When cutting into lemons, it’s wise to take note of the ratio of zest, pith, and flesh. The segments of flesh should be translucent and pale yellow.
Depending on the lemon variety the ratio of the pith (the white bit) will change in thickness and changes colour slightly as it ages until it reaches a dirty grey colour.
Take note that pith should always be a bright white-slightly off-white colour. Grey, brown, or dirty looking pith is a sign that the lemon has gone bad.
Smell
Squeeze ’em, not too hard, just enough to get those citrus oils onto your skin. If you can’t smell that strong citrus smell, then that lemon is a dud.
On top of that, if you smell anything other than fresh citrus, like a musty or rancid aroma, this indicates that the lemon is either going or has gone bad.
Texture
Your lemons should always feel firm when gently squeezed. Any sign of softness or individual squishy spots and that lemon is at best tired and breaking down, and in the worst case is bad and rotten inside.
Taste
Lemons are beloved for their zingy freshness; the way they lift a salad dressing, cut through fatty oils on grilled meat, and refresh the palate after a long dinner.
A lemon should always have that mouth-puckering zing; it’s fresh and invigorating. If the lemon tastes weak or has a dusty taste, then it’s gone bad and should be discarded.
Mould
This should be easy to spot as it usually blooms over the skin of the lemon. It will appear first as a white speck and slowly grown and change into a green-grey colour.
If removed early in the white speck stage, this mould is not a big concern. However, once the mould has spread and become green-grey, the lemon should be discarded as it has gone bad.
What Happens if You Eat a Bad Lemon
For most people, eating a bad or rotten lemon won’t be the end of the world. Unfortunately, due to the possible presence of bacteria, viruses or toxins from the lemon juice that has gone bad, consuming the soured juice will cause food poisoning within a matter of hours.
For those with autoimmune issues, are very young or elderly, there are significant concerns as it can cause complications. It is advised to seek medical assistance as soon as possible.
How to Tell if Lemon Juice is Bad
Despite being high in acid, lemon juice can turn bad much quicker than a whole lemon. Lemon juice with preservatives will have a little longer, but both require appropriate storage for the longest shelf life.
When lemon juice goes bad it takes on specific traits, and they are:
Appearance
Fresh lemon juice should be pale lime-yellow. Lemon juice that has gone bad will be much darker in colour, almost burnt orange-brown.
Smell
Your fresh lemon has a pleasant citrus aroma, and is inviting. However, lemons or lemon juice that has gone bad will have a sour, rotting or dusty smell that permeates the citrus smell. If you notice anything that causes your nose to wrinkle, discard the source immediately.
Taste
Whilst fresh lemon juice will cause your mouth to pucker momentarily, lemon juice that has gone bad tastes extremely sour. It is likely to also have a hint of mould/dusty tones. Do not swallow this juice, as it can cause food poisoning.
How Long Do Lemons Last?
Unless you have a lemon tree growing in your backyard, your fresh lemons will come from a market or supermarket. Once you’ve brought them home, your lemons will be in a race to the end, but there are a few things you can do to get the most shelf life for them.
Lemons can keep far longer than most people realise, with lemons that are kept in the cool and dark lasting the longest. Another top tip to preserve your lemons for the maximum amount of time is to zest and juice them.
The two most common places to store your lemons will be in the fridge or on your countertop. The shelf life for these two options is vastly different. This table gives an easy to read and remember timeframe for your lemons:
| Fridge | Counter | |
| Fresh lemons | 3-6 weeks | 2weeks – 1 month |
| Cut lemon | 2-3 days | 24hrs |
| Freshly squeezed lemon juice | 4-5 days | 12hrs |
However, if you’re a fan of lemon juice all year round, then regularly freezing the juice in batches is a great option, as it will last for up to 4 months. You can also freeze lemons whole, but they’re best suited to juicing or baking once thawed.
How to Store Lemons
Fridge
The quick and easy option is just to place your store-bought lemons straight into the crisper drawer. Once there, your lemons will last on average about 4 weeks.
However, there’s a quick and simple trick to squeeze an extra couple of weeks out of them. Rinse and pat dry your lemons, to ensure there’s no freeloaders or dirt on the skin. Then place the clean lemons into a freezer bag and squeeze all the air out.
Once the bag is free of any contaminants and excess air, place the lemons in the same crisper drawer. This removal of oxygen and any possible dirt or insects will prevent the lemons from dehydrating or spoiling due to moisture.
Note: It is advisable to regularly check your lemons, and to attend to any moisture or blemishes if noticed.
Freezer
Freezing your lemons couldn’t be easier. To freeze them whole, simply rinse the lemons in clean water, and pat dry. Once dry, place them in a freezer bag and remove any excess air.
Just like in the fridge, by removing the air from the bag, you’re preventing them from dehydrating quicker. The thicker freezer bag also gives some protection against freezer burn.
You can also freeze your lemons in slices, or halves the same way, but do note that once thawed they can only be used for cooking or juicing.
Freezing lemon juice couldn’t be easier. All you’ll need is an ice cube tray, or other small portioning freezer-proof kitchenware, and a juicer. Pour the lemon juice into the moulds, and freeze until solid. Once frozen you can transfer the cubes into a freezer bag or airtight container, and simply thaw a portion when required.
Countertop
Whilst this is the least promising storage option, there is something visually appealing about seeing lemons in a fruit bowl. If this is your only option, then do keep that fruit bowl where you’ll be able to regularly check the contents.
Lemons that are stored on the countertop will only last for up to 1 month, with many lemons being past their best within 2 weeks. Take note to inspect them for any signs of mould or blemishes, and use them as soon as possible.
What to Do with Old Lemons
It’s a pretty common problem, and many cooks find they end up throwing out lemons because they’ve gone bad before they could be used. But, there are still ways to get value for money out of that lemon that’s past its best.
Here are some top tips on how you can use up leftover or old lemons.
Zest-it!
Even lemons that are ageing or that have dried out can still be useful. The zest is easily zested with a citrus zester and frozen for later.
When it comes time to use the zest, simply thaw and add the zest to your dish. No need to rehydrate, just put it straight in!
You can also use lemon juice, in water, to prevent peeled fruit from browning whilst preparing them for fruit salads, or other dishes.
Stain-away
Rather than leaving stains, old lemons can help remove stains from garments or fabric. For instance, apply a cut lemon to a freshly stained white apron before the stain dries, and the acid in the lemon juice will help reduce or remove the stain when washed.
Scrub-a-dub-dub
Don’t throw out older lemons; you can use them to clean several kitchen goods. The acid in lemon juice is ideal for helping to remove any bacteria on chopping boards, and also those unsightly stains from spices.
All you need to do is rub a cut lemon back and forth over the surface a few times, rinse, followed by a hot water and soap wash, and then air-dry. This should shift the stains, and remove most bacteria.
You can also use lemons to treat the plastic lids of blenders, food processors, plastic containers, etc. Give them all a good scrubbing with a cut lemon and watch the stains fade away – and they’ll also smell lemony-fresh!
Using lemons and salt to clean your stainless steel is also an eco-friendly option for household cleaning jobs. Scatter sea salt over the surface and then apply half of a lemon to use as a scrubber.
Together, the salt and lemon will remove most dirt, grime, and bacteria, and restore some of the surface’s shine.
A final cleaning tip, if you have a kitchen sink disposal unit, you can use lemons to give it a good clean and to remove nasty smells. Simply place a few wedges of lemon, or other citruses, in the unit, and turn it on.
Within seconds the lemon will have cleared any bits and pieces and added a citrus freshness.
Note: Do not use lemons that have dried out and feel like golf balls. Placing these into a disposal unit could cause damage to the unit.
To Sum Up
Lemons that have gone bad will be noticeable; they will have turned either dark yellow-brown, or be covered in mould in extreme cases. Lemon juice that is no longer safe to consume will turn dark brown, and smell rotten.
Fresh lemons will last for up to 6weeks in the fridge, and only 2-4weeks on your countertop. Freezing whole, or part thereof, your lemons will increase their shelf life.