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Does Simple Syrup Go Bad?

Even with its high sugar content, simple syrup can go bad. In most cases, simple syrup will have an expiration date on the packaging, which can be between one to six months once opened. 

The shelf life of simple syrup also depends on various factors such as the water-to-sugar ratio, preparation method, and storage technique. Nonetheless, unopened simple syrup can stay good for a long time, especially if it is sugar-free simple syrup

How Can You Tell if Simple Syrup Has Gone Bad?

It’s easy to identify simple syrup that has spoiled by observing the following details:

  1. Cloudy Appearance

Simple syrup should be clear and smooth. When it has a cloudy appearance, it has possibly gone bad and is unsuitable for use.

  1. Foul Odor

When a syrup starts developing a bad smell, it’s probably a good idea to discard it and make a fresh batch.

  1. Forming Molds on the Syrup

Sugar and water can turn into mold, obviously making the syrup unusable.

How Long Does Simple Syrup Last?

Once you know what a simple syrup is, you can understand the various factors that can affect its shelf life.

Sugar to Water Ratio 

The ratio of water to sugar can determine how long a syrup will last or how fast it will go bad. If the ratio is 1:1 sugar to water, the syrup will most likely last for a few weeks or up to a month. If the ratio used during preparation is double the sugar to water, the syrup will last for around six months. 


Flavored syrup tends to spoil more quickly than its plain counterparts. This is because the fresh ingredients such as herbs and fruits will eventually begin to decompose.

Type of Syrup

Because they contain stabilizing ingredients not found in home recipes, some store-bought syrups can last longer than those made at home.

Type of Process

There are two methods of making simple syrup–cold and hot. The cold process requires stirring ingredients until they dissolve, while the hot process involves boiling the two elements. The hot process creates more stable syrup and allows the sugar to dissolve completely and evenly. Cold-processed simple syrup has a shorter shelf life.


Crystallization refers to melting sugar in water, which can sometimes be difficult because sugar molecules tend to stick together. Sugar can remain in the solution if it’s not agitated to the point of boiling, and crystalized simple syrup has a shorter shelf life, unlike low-carb simple syrup. 

Simple Shelf Life Guidelines

Some of the simple shelf life guidelines that you should follow when dealing with simple syrup include:

Storage Conditions

Refrigerated homemade syrup can last for two to four weeks. Syrups left at room temperature can last for just one week.

Preparation Process

Cold processed syrups can last for a week. Hot processed syrups with a 1:1 sugar to water ratio can last for a month and those with a 2:1 ratio can last for around six months.

How to Extend the Shelf Life of the Simple Syrup

One of the ways to stabilize simple syrup is to reduce its chances of becoming crystalized during storage. You can do this by adding corn syrup or lemon juice.

How to Store Simple Syrup

Proper storage is one of the best ways to prevent your simple syrup from going bad. The following are some crucial tips that will help you in this regard:

  • Store the syrup in a sterilized, air-tight glass container.
  • Rinse your storage container using boiled water to prevent contamination.
  • Homemade syrup should be refrigerated—the cold temperature inside the fridge can inhibit the growth of bacteria, which will allow the syrup to last longer.
  • If you store your syrup in a bottle, clean the opening regularly. Sugar crystals can form at the lid, providing an environment for bacteria to breed.
  • You can extend the shelf life of your syrup for up to a year when you keep it at freezing temperatures. 
  • Follow any storage instructions printed on off-the-shelf syrups.

Final Thoughts

Simple syrups are a good way to sweeten your homemade cup of joe or store-bought coffee; however, you must be careful about which syrups you consume. Skinny Mixes Syrups  are delicious and offer low-carb simple syrup options that will help you cut extra sugar and calories.