How Long Does Simple Syrup Last?

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It’s essential to know the shelf life of the more “longer lasting” ingredients. Some people think things like simple syrup can last forever. Unfortunately, that’s just not true.

While some syrups can last a long time, they do go bad. Being able to tell when they’re bad and when they’re safe to eat is a piece of knowledge that every single person in the kitchen should know.

Whether you’re pouring a simple syrup for Hawaiian shaved ice or a mixed drink, read on to learn about how long it lasts, its shelf life, and how to tell when it’s time to toss it out.

How Long Does Simple Syrup Last?

The length depends on the ratio of sugar to water. More sugar means a longer shelf life.

There are a few different ratios and types of simple syrup, but you can expect the shelf life to be somewhere between 1 and 6 months if kept refrigerated in an airtight container. If left outside of the refrigerator, the sugars can begin to crystalize, making the syrup unusable within two weeks.

SEE ALSO: Does Sugar Go Bad?

Simple syrups typically have just two ingredients: sugar and water.

There are two “main” types of syrup. They are split by the ratio of sugar to water. The 2:1 sugar to water syrup is known as rich simple syrup and can last much longer than a 1:1 ratio.

They can also be made with a hot process or a cold process. The most commonly used process is a hot process. This process ensures the longest shelf life.

Does Simple Syrup Need To Be Refrigerated?

If you want the syrup to last as long as possible, keep it in an airtight container and refrigerate it. That’s the best way to do it.

How Long Does Simple Syrup Last At Room Temperature?

Simple syrup shouldn’t be kept a room temperature for long as it can go bad in as little as a week. The higher temperatures and airflow are always going to make things go bad faster.

Simple Syrup Shelf Life

Colored Simple Syrups


  • Homemade 2-4 weeks pure, 1-2 weeks with flavorings

Hot Process

  •  1:1 ratio – 1 month
  •  2:1 ratio – 6+ months

Cold process

  • Use within a week

Why does the ratio matter so much, and why is the cold process so bad compared to the hot?

The answer to both of those questions is simple chemistry. Most things in chemistry like to be equal.

Think about when you make pasta. You salt the water, cook the pasta in the water, and then your pasta tastes salty. That’s because some of the salt in the water moved into the pasta.

The chemicals are “trying” to equalize the amount of salt in the water and the pasta.

A similar thing happens in the syrup but in reverse. When bacteria grow in simple syrup, they almost immediately die.

This is because the water is being pulled out of the bacteria and into the syrup. It’s trying to equalize the amount of sugar and water in both the syrup and the bacteria.

Since there’s already so much sugar in the syrup, a lot of water gets pulled from the bacteria. This kills the bacteria.

To put it simply, a higher ratio of sugar to water will make a thicker syrup and a longer shelf life. Any flavoring or additional additives to the syrup will lower the shelf life.

How to Tell if Simple Syrup is Bad

  • Crystallization: crystals appear in the bottom, not necessarily “bad.”
  • Bacteria: cloudy, foul smell, throw in the garbage immediately
  1. One way to tell if your syrup is bad is by checking the color. If the syrup appears cloudy, it means bacteria are actively growing in your syrup and need to be thrown out.
  2. An additional way to tell is by smelling. Any foul odor at all is indicative of syrup that’s gone bad.

If your syrup has gone bad, throw it in the trash. It’s just sugar water.

There are two ways simple syrup can go bad. It can crystallize and become very thick with large, hard chunks or become infested with bacteria.

Either way, with a pure simple syrup, it’s straightforward to tell if something is wrong. The syrup should be crystal clear. If it’s beginning to crystalize, you’ll be able to tell just by looking.

The crystals can usually be found near the bottoms of the containers. Crystals do not mean that the syrup is inedible, only that it is being stored improperly.

Bacteria infestations are a bit more serious. Luckily, it’s relatively easy to tell if it’s been infested.

Can Simple Syrup Make You Sick?

If the syrup is very bad and foul, then yes, it absolutely can make you sick. The main reason simple syrup goes bad is due to bacterial growth. Any bacteria that get into your body that aren’t supposed to be there can cause a multitude of medical issues.

Some of the world’s worst sicknesses come from bacteria. So if your syrup looks like it has bacteria, don’t risk it. Get rid of it. The ruined syrup will ruin your drinks anyway.

However, if it just has some crystallization, it’s most likely fine to use. However, I would consider getting more sooner than later.

How to Store Simple Syrup

Other than freezing, this method has made my syrup last the longest. You can use plastic bins, jars, bottles, or whatever airtight containers you can find. It doesn’t have to be perfect, but the tighter the seal, the better.

The seal and the lower temperature of the refrigerator keep the syrup stable and prevent bacterial growth.

If you’ve made your syrup from scratch, make sure to let it cool before putting it into an airtight container and sticking in the fridge.

In my experience, if you put hot food in a container and fridge it, it goes bad much faster.

Like simple syrup, I like to keep things simple.

If you want a long-lasting, simple syrup, go for a rich (2:1 ratio) syrup. Stored in the fridge in an airtight container, it can last upwards of 6 months.

If it’s going bad, you’ll be able to tell based on color and smell. Anything that’s cloudy or foul-smelling has gone and should be removed and tossed out.

Written By Tara Williams

Tara is a food writer that has been editing and authoring articles for KitchenSanity since its founding. Her writing offers personal experience from experimentation with food and recipe creation. If you’re looking for simple tips, she will make your journey in the kitchen straightforward with a dash of fun.