How Long Will Simple Syrup Last?

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If you’ve never used simple syrup before you probably don’t understand the benefits of this basic ingredient. It can be added to drinks, desserts, breakfasts, sauces, and even cooked with.

A must for anyone with a sweet tooth, if you do know simple syrup you’ll know how frustrating it is to go and add a drop to your drink only to find an empty bottle. Simple syrup isn’t often used in large quantities, but it has a habit of running out without you realizing.

So wouldn’t it be great if you never had to worry about missing out? Never having to serve a too-bitter cocktail when you’re trying to impress. Never having to rush up a batch when you’re overrun with visitors.

Never having to start from scratch when a recipe calls for a spoonful. Simple syrup is easy to batch make, as it requires only a few ingredients and a two-step process.

If you could make a large quantity in one go then you’d never have to worry about being stopped from adding a little sweetness to your day. Wouldn’t it be great to have a never ending amount on hand without worrying about it going bad?

Before you reach for the sugar bag, we need to ask ourselves does simple syrup go bad? The shelf life of simple syrup is good. Anywhere from 2 weeks to six months depending on how it’s been made.

On average, a bottle of simple syrup in the fridge should last for around one month – but there are ways to improve that.

What is Simple Syrup?

Simple syrup is a mixture of water and sugar. It’s a very basic ingredient, and one that can be adapted to suit your tastes. It’s most commonly used in cocktails, where it takes the edge off more bitter ingredients.

However, it’s also the basis of many sauces, both sweet and savory. If you’re a fan of cooking or baking you might have used simple syrup without realizing.

Traditionally, simple syrup is made with water and granulated sugar. It’s an easy process to master, and once you’ve got the hang of it there are many options to try.

Simple syrups can be made with brown sugar and other types of sweetener, although the shelf life of these is varying. For a unique taste there are also flavored simple syrups, but we’ll get to them later. Flavored simple syrup varieties include honey simple syrup, rosemary simple syrup, cinnamon simple syrup, and other flavors including hibiscus, lavender, and blueberry. There are many options for a good cocktail recipe or drink recipe.

How do you make simple syrup?

There are two main types of simple syrup, and it all depends on the ratio of sugar to water. The most common is 1:1, or one-to-one. This uses one part sugar to one part water.

This will result in a thinner syrup that is good for baking and cocktails. Typically, a cup of sugar will be added to a cup of water, resulting in roughly two cups of syrup. This is a decent sized batch.

The second option is 2:1, known as rich simple syrup. The addition of the extra part sugar creates a thicker, sweeter syrup. This is a good base for caramels and other sweet desserts. Rich simple syrup is the longest lasting of the syrups. Sugar is a preservative, so the more you add, the longer it lasts.

With only two ingredients there is room to play around. To make a very thin syrup you can use 1 part sugar to 2 parts water, although this will have a shorter shelf life.

To make, add the sugar to the water and heat while stirring. The key is to do it gently. Keep the heat low to avoid a boil, and don’t stir too vigorously or too often.

Once all the sugar crystals have dissolved, remove the syrup from the heat and add it to your (sterilized) container and leave it to cool. See, simple!

What affects the shelf life of simple syrup?

While simple syrup has a long shelf life, it doesn’t have an indefinite shelf life. Like most things, syrup will go off if left for too long and can be dangerous to consume out of date.

There are multiple different factors that will affect how long your syrup lasts.


A dreaded word for any chef, crystallization is when your sugar molecules stick together and refuse to dissolve. Sometimes this effect is desirable, but when it isn’t, it’s a nightmare. 

You’ll know if your syrup has crystallized because the sugar crystals are easily visible. There are ways around it, but unfortunately there’s no real guarantee it won’t happen. Crystallization often seems like nothing but a case of bad luck. It happens to even the best of chefs.

While simple syrup is relatively easy to make, it is subject to the whims of cooking. The best way to avoid crystallization is to use granulated sugar and to go slowly when heating. A good simple syrup will be completely clear when made.

Cold Process

Cold process simple syrup is when rather than heating up your sugar, you dissolve it simply by stirring it.

Some claim that this results in a better flavor, so if you’re a syrup connoisseur you might want to give it a go. However, for most of us there will be no discernible taste difference.

If you remember your high school science, you won’t be surprised to hear cold process simple syrup takes much longer to make. The application of heat speeds up the process greatly.

Honestly, it’s a lot of work for not much in the way of results. Not to mention, cold process syrup goes off much faster than hot process syrup.

If you still want to give it a go, use the same ratios of sugar to water and then stir vigorously. You’ll know when it’s done because the syrup will be completely clear, with no visible sugar particles.

Adding Flavorings to Simple Syrup

Simple syrup is a great base for different flavors, such as herbs, fruits, and spices. These can be added before heating the mixture, or left to infuse. Unfortunately, once you’ve added those extras the shelf life of simple syrup is reduced.

When you add the flavorings you’ve added a new ingredient with the potential to decay. While sugar is a preservative, it won’t preserve forever. Flavored simple syrups may only last for a week or two. 

Luckily, they taste really good, so they might not hang around for that long anyway. If you did make a large batch you’re struggling to get through, flavored syrups are a thoughtful gift!

How to store simple syrup

The very best place to keep your simple syrup is in the refrigerator. The refrigerator is designed to increase the life of your produce and simple syrup is no exception.

Keeping it in the fridge slows the growth of any bacteria, leaving it safer to use for longer. Make sure the lid is on tight, and keep the syrup away from smelly foods.

There’s no real downside to refrigeration. Outside of shelf life, there are benefits as well. Perhaps the most common use for simple syrup is as an addition to cocktails. Cold simple syrup will help keep your cocktail cool.

Does simple syrup have to be kept in the refrigerator? No, but it will increase its longevity if you do. Once you’ve put it in the fridge, keep it in the fridge.

What do I keep simple syrup in?

The best way to store your simple syrup is in a glass container with a tight seal. Think mason jars or anything you might store jams and jellies in. While plastic is okay, it’s harder to sterilize, so your syrup is more likely to become contaminated. 

Sterilizing a glass container is about killing the germs and bacteria that hang around on surfaces. To sterilize a jar begin by washing it in hot soapy water. Or, simply pour over boiling water. When this is done, avoid the urge to wipe it dry.

This won’t undo all your hard work, but it can reintroduce bacteria. Instead, turn the oven on to a low heat, roughly 320F, and place the jars in the center for about fifteen minutes. If you’ve used boiling water, don’t handle the jars with your bare hands.

The heat from the oven will dry the jar, and kill any remaining bacteria. Carefully remove from the oven, allow to cool slightly for handling, and add your syrup!

Don’t touch the inside of your clean jars, or you’ll need to start again. Make sure the lid is screwed on tight, so the smell of other foods don’t affect the taste of your syrup.

How to serve simple syrup

Once you have your jar of syrup well sealed in the fridge you might think you’ve done all you can. But there is one more thing you can do to prevent the growth of bacteria: pour, don’t dip.

Pouring your syrup out of the container is better than dipping a spoon in. No matter how clean you keep your cutlery, bacteria has a habit of hanging around.

Especially in a kitchen, where all types of different ingredients are being thrown around into the atmosphere. Even if you think you have the cleanest spoon going, it still risks introducing foreign objects into your syrup. And then the germs start growing.

If you’ve bought syrup in shops you’ll notice it comes in long neck bottles. This is the best for storage, as it allows for an easy pour and measurement. 

Quickly dipping a spoon in isn’t the end of the world, but if you can avoid it then you should. Anything to keep your syrup fresh for as long as possible.

How long does simple syrup last?

Simple syrup lasts for at least two weeks, and up to six months depending on the consistency and if kept in the fridge. If made hot then rich simple syrup, mixed with two parts sugar to one part water, can last up to six months. One-to-one simple syrup lasts about a month.

Cold processed simple syrup only lasts for roughly half the time, so you may have only two weeks to use it. The application of heat during the dissolving process sterilizes the sugar giving it a longer shelf life. 

If you’ve added flavorings to your simple syrup, the shelf life decreases again. Simple syrup at room temperature lasts for roughly one to two weeks.

Stabilizing your simple syrup

Anything you do to try and increase the life of your syrup is going to effect the taste and consistency, so bear that in mind before making a large batch.

The most obvious option is to add more sugar. The richer syrups are the longer lasting ones, therefore the quickest way to create a longer lasting syrup is to increase the ratio of sugar to water.

Some recommend adding vodka to increase the shelf life. Much like sugar, alcohol is a preservative, and a high alcohol content liquor like vodka doesn’t go bad for a very long time.

Adding vodka is a less common option, so there’s less information available about the quantities to use, but a small amount is best. Adding vodka reduces the number of ways the syrup can be used. 

To prevent crystallization there are a few different options. Adding a teaspoon of lemon is a popular method, or a teaspoon of cream of tartar. These acidic ingredients break down the molecules of sugar into glucose and fructose.

The smaller particles prevent the sugar molecules from sticking together and forming crystals. However, the method has its downfall. Both ingredients will alter the flavor of your syrup.

If you want to prolong the life of your syrup by adjusting the ingredients consider how much you’re willing to sacrifice flavor. The flavor of the syrup is very important, as is the consistency. It might be better to just make a smaller batch.

My simple syrup has crystallized. Can I fix it?

You can, although it takes a little bit of effort. 

Crystals don’t just form in the initial heating stage. You may find that one day you go to open your jar only to find your once pristine syrup is now filled with clumps of sugar. This is incredibly frustrating, but difficult to avoid.

Much as with making the syrup, the best way to remove sugar crystals is to go low and slow. Return your mixture to a pan, and heat through slowly on a low heat until all the sugar is dissolved.

Avoid stirring as much as possible. While you should always keep an eye on a hot stove, try not to disturb your syrup as it heats back through.

If you’re only reheating a small amount it’s worth asking, is this worth it? The process to remove the sugar crystals is essentially the same as making the syrup, so unless it’s a large amount, or you’re completely out of sugar, then it may be best just to start again.

Can you freeze simple syrup?

Yes! Keep your syrup in a well sealed container (we don’t want any freezer burn getting in) and it freezes easily and can be used again.

The thinner one-to-one simple syrup does tend to freeze solid, so remember that if you want to get it out in a hurry. Rich simple syrup is unlikely to freeze completely, due to the very high sugar content.

In the freezer, simple syrup should last for up to a year.

My simple syrup has turned cloudy. Can I fix it?

Unfortunately, no. Simple syrup should be clear and easy to see through. Once the syrup has gone cloudy, that means it’s starting to grow bacteria and mold.

Consuming mold can make you very sick, so even if you think your syrup should still have a week left, it’s better not to take the risk. 

If you’ve just made your sugar syrup, and it’s already cloudy, that means something went wrong in the process. This could be anything from the sugar, the water, or the pan you used itself.

Even left over bacteria on the spoon can make a difference. It’s frustrating, but the best thing to do is to throw it away and start again. Try sterilizing the pan and spoon before you start, as that could be the quickest solution.

It’s very easy to spot when your syrup has gone off, as there will be an obvious difference between the clear syrup and the cloudy syrup. So if you start to notice clouds don’t expose yourself to risky bacteria by holding on to the syrup past its date.

Store bought simple syrup

As simple syrup becomes more popular the range that can be found in shops has greatly increased, including flavored options.

The average shop bought simple syrup has a longer shelf life than homemade, and won’t always need to be refrigerated. This is because it’s more likely to contain a larger number of preservatives. 

Store bought syrup can become quite expensive, and the weird thing is you pay more for fewer ingredients. Cheaper syrups tend to be packed full of various preservatives, so they can be kept on the shelf for longer. A high quality syrup only needs sugar and water, anything else might affect the taste.

The major benefit of homemade simple syrup is that you’re able to adjust it to your own tastes. Store bought syrup is often sweeter, and can have an artificial aftertaste. As it’s so easy to make, we recommend trying your own.

It may seem as though there’s a lot that can go wrong, but as with most recipes the key is practice and patience. Crystallization and cloudy syrup is generally a result of bad luck. Most times you make the syrup it should be a quick and easy process.

How can I make my syrup last longer?

Always keep it in the refrigerator in a sterilized container with a tight lid. The best way to make syrup last longer is to make a rich syrup with more sugar than water, and to heat it to get the sugar to dissolve.

Made like this, a batch of syrup can last up to six months, although if it starts to turn cloudy it should be thrown away regardless of age.

Frequently Asked Questions

How do you know when simple syrup goes bad?

You can tell when simple syrup has gone bad because it starts to grow cloudy. When properly made, simple syrup is clear in appearance. Any cloudiness is a sign that bacteria is starting to grow, and the syrup needs to be thrown away. If it’s been left for a while, the syrup may start to smell bad. It should then be disposed of immediately. Bacteria might be growing because there was an issue in making the syrup, it was stored improperly, or it’s been left too long.

Another way simple syrup can go bad is crystallization. This is when crystals begin to form in the syrup. This isn’t a health risk like bacteria, but it’s still a sign that there’s a problem with the syrup. If you’re making your own simple syrup, be aware that crystallization can occur at any stage.

Can bacteria grow in simple syrup?

Yes, bacteria can grow in simple syrup. Despite the short ingredients list, bacteria is still able to grow. You can see when bacteria are growing, because the syrup will turn cloudy. Once this happens the syrup is no longer safe for consumption, and needs to be trashed.

The best way to avoid bacteria is to store syrup properly and use it quickly. Keep simple syrup in the fridge for a longer shelf life, and to avoid bacteria growth. The lid should be tightly secured, and avoid dipping anything into the syrup. Even a spoon can introduce bacteria.

If you’re making your own syrup, use the hot process method to prolong the use of the syrup, as it kills bacteria better. Store your syrup in sterilized containers. Increasing the sugar to water ratio also helps. The higher the sugar content, the longer lasting the syrup.

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Cassie brings decades of experience to the Kitchen Community. She is a noted chef and avid gardener. Her new book "Healthy Eating Through the Garden" will be released shortly. When not writing or speaking about food and gardens Cassie can be found puttering around farmer's markets and greenhouses looking for the next great idea.
Cassie Marshall
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