How Long Does Simple Syrup Last? Can It Go Bad? Here’s How To Tell…

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So you’ve just discovered the beauty and convenience of making simple syrup, so you made a lot. And by a lot, we mean “you-can’t-finish-it-in-a-year-even-if-you-throw-parties-every-day” kind of a lot.

Guilty? We know the feeling. We’ve been there too.

We understand that while making simple syrup is pretty easy, figuring out if you can finish it all before it gets spoiled is not an easy feat.

And so, you finally Googled: Does simple syrup go bad?

The simple syrup doesn’t keep it as simple as you think. But we won’t sugarcoat it if you want to know the real deal!

Short Answer: While syrups can last for a long time, they still go bad at some point.

That’s why it’s crucial that you can tell if the syrup is already bad or still safe for consumption, and we’ll teach you how to do that in this article.

Additionally, you’ll also learn the following information:

  • What is simple syrup?
  • Can simple syrup go bad?
  • What are the signs that simple syrup has gone bad?
  • How long does simple syrup last?
  • How to extend the shelf life of simple syrup?
  • How to store simple syrup
  • … and other frequently asked questions about it!

If you’re ready, let’s dive right in!

What is a Simple Syrup?

Simple syrup is a sweet syrup commonly used in various desserts and drinks recipes. However, the most fantastic thing about this versatile syrup is it’s made using only two ingredients: sugar and water.

Traditionally, this syrup is produced by mixing granulated white sugar and water and bringing it to a boil over medium heat until the sugar has melted.

Nowadays, different sweeteners are used to make simple syrup—honey, agave syrup, brown sugar, and many more.

Not only that, but some people also add different types of ingredients to create flavored simple syrups. Some of the most common simple syrup flavors are rosemary, hibiscus, cinnamon, blueberry, and many more.

While these additions can help enhance the flavor of the syrup, it’s essential to keep in mind that whichever ingredient you use can affect the recipe’s shelf life since it deviates from the original simple syrup composition.


They comes in three different types: thin, medium, and thick. These types are classified based on their consistency determined by the sugar to water ratio they contain.

With that said, here are their corresponding rations:

  • Thin: 2 parts water + 1 part white sugar
  • Medium: 1 part water + 1 part white sugar
  • Thick: 1 part water + 2 parts white sugar

Does Simple Syrup Go Bad?

Unfortunately, the simple syrup can go bad over time, even if sugar can last indefinitely all by itself.

Here’s why: To make simple syrup, sugar is combined with water which is at risk of evaporation. Water in simple syrup evaporates over time, altering the sugar to water ratio and the original composition of simple syrup.

The change in the ratio allows microorganisms to grow, which may cause spoilage of the syrup.

How Long Does Simple Syrup Last?

With that said, how long can you enjoy simple syrup? Various factors affect the shelf life of simple syrup. These are as follows:

1. Sugar to Water Ratio

Sugar is a known preservative. That’s why the higher the sugar to water ratio of the syrup is, the longer shelf life it has.  Because of this, the thinner product will spoil a lot faster than one with a rich consistency.

2. Flavor

Flavored syrups last shorter than plain ones. Why is this so? This is because fresh ingredients, such as herbs and fruits, are commonly used as flavoring ingredients.

Any recipe that includes fresh ingredients has a shorter shelf life because these ingredients will decompose naturally even if there’s sugar in the syrup.

  • Fun Fact: Even if you use dried herbs, there’s still a chance that it will decompose faster than plain syrups as these ingredients might introduce bacteria to the syrup.

3. Type of Syrup

Typically, store-bought syrups last longer than homemade syrups since they usually contain stabilizing ingredients that you can’t find in homemade recipes.

4. Type of Process

There are two ways to make simple syrup: the hot and cold process. The hot process involves boiling the two ingredients, while the cold process requires stirring cold ingredients until they dissolve.

The hot process creates a more stable simple syrup between the two processes as these allow the sugar to dissolve completely and evenly. Because of this, a cold processed simple syrup will last shorter.

5. Crystallization

Melting sugar in water is not easy due to crystallization wherein the sugar molecules stick with one another, making them insoluble in water.

This happens when too much sugar is in the solution or agitated too much as it boils. Crystallized simple syrup will get spoiled faster.

Now that we’ve got that settled, here are the simple syrup shelf life guidelines that you should know about:

6. Shelf life According to Storage conditions:

  • Room Temperature: 1 week
  • Refrigerated: Homemade pure (2 to 4 weeks) and flavored syrup (1 to 2 weeks)

7. Shelf Life According to Type of Process

  • Hot Process Syrups: 1:1 ratio (1 month) and 2:1 ratio (over 6 months)
  • Cold Process Syrups: 1 week

How to Extend the Shelf Life of Simple Syrup

To stabilize your simple syrup, you have to lower its chances of getting crystallized during storage. You can do that by adding any of the following ingredients:

1. Lemon Juice or Cream of Tartar

These highly acidic ingredients can prevent crystallization by breaking down sugar molecules into fructose and glucose.

2. Corn Syrup

The logic behind adding corn syrup to prevent crystallization is all about chemical reactions as it involves forming chemical bonds between two simple sugars (glucose). (*)

Adding these ingredients is an effective solution in preventing crystallization, but it comes with one catch—it can alter the flavor of your simple syrup.

  • Pro Tip: If you want to maintain the flavor of your syrup, simmering your sugar syrup for 10 minutes will do the trick.

Instead of boiling the syrup, let it simmer for a longer time to allow all the sugars to dissolve in the water completely.

What are the Signs that Simple Syrup Has Gone Bad?

The simple syrup will get spoiled faster than the expected shelf life when stored improperly. There are two signs of spoiled simple syrup that you should look out for. Here they are:

1. Changes in appearance

Simple syrup is completely clear and translucent. When it starts to develop a cloudy appearance, it has been contaminated. The contamination may be brought about by unclean water or an unknown chemical in the sugar you used.

Another sign that your simple syrup has gone bad is mold growth resulting from bacterial contamination that may occur when the water in the simple syrup has evaporated.

3. Foul Odor

A weird smell is the biggest sign of contamination and spoilage, so discard your sugar syrup right away if it has a foul smell.

How to Store Simple Syrup

Proper storage is a must to prevent premature spoilage of your sugar syrup. Below are some of the food storage tips that you should know about:

1. Refrigerate homemade simple syrup.

The best place to store your sugar syrup is your refrigerator. The cold temperature inside the fridge can inhibit bacterial growth, allowing you to use your simple syrup for longer.

2. Store homemade syrup in a sterilized airtight glass container.

To avoid contamination, make sure to sterilize the glass container first. You can do this by rinsing it using boiling water.

It’s also essential to use an airtight container to ensure a tight seal that can protect the syrup from contaminants and oxidation.

  • Pro Tip: Use Mason jars as these come with tight lids.

3. Wash the cap of the bottle from time to time.

There’s a high chance that sugar crystals will form at the cap. Cleaning this will prevent the further formation of crystals.

4. Follow the storage instructions when storing store-bought syrups.

If the instructions require you to store the syrup at room temperature, place it in your pantry—far from heat sources.

5.   Freeze simple syrup if you want it to last longer.

When you freeze simple syrup, you can extend its shelf life for up to a year. But please be warned, only syrups with a 1:1 sugar to water ratio freezes well.

Final Words

Does simple syrup go bad? Unfortunately, the simple syrup will still go bad even with its high sugar content. The good news is that it lasts for a long – 1 week to 1 year—depending on the type of syrup you have.

Unfortunately, it’s a chance to get spoiled faster due to crystallization and contamination.

What’s the magic formula to prevent these? You’ve got everything you need to know in this article. Just follow the storage and stabilization tips we’ve shared with you. It’s that simple.

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