How Long Does Simple Syrup Last - Simple Syrup 101 (2024)

I’ve shared quite a few simple syrup recipes and figured it would be helpful to share a simple syrup 101! This covers all kinds of questions, including my most frequent question of “how long does simple syrup last?”

Other frequently asked questions that we’ll discuss in this post include:

• What is simple syrup?
• How to store simple syrup
• Can you store simple syrup in plastic?
• Does simple syrup go bad?
• Does simple syrup need to be refrigerated?
• Can you freeze simple syrup?

What is Simple Syrup?

Simple syrup is usually made with equal parts water and sugar in terms of volume (i.e. 1 cup of water to 1 cup of granulated sugar).

The mixture is heated to help the sugar dissolve, which yields a sweet syrup that can be used to sweeten and flavor just about anything!

My favorite way to flavor it is to add vanilla bean paste. This packs it with delicious, warm flavor that goes well with just about everything!

Ingredients & Substitutions

Like I mentioned above, simple syrup is pretty easy to make! However, there are some substitutions and swaps you can make if needed.

• Water – Room temperature tap water works great in this recipe.
• Granulated Sugar – I like using granulated sugar because it’s what I usually have on hand, but you can also use extra fine sugar or caster sugar.
• Vanilla Bean Paste – This is optional, but I like to add pure vanilla bean paste. It speckles the syrup with little vanilla seeds that give it such a gorgeous look! However, you can also use regular vanilla extract! Just be sure you’re using good quality stuff because it has a huge impact of the flavor of this syrup.

How Do You Make It?

I love this recipe because it seriously takes about 5 minutes to make!

Start by pouring the water and granulated sugar into a small saucepan. Cook over medium heat and stir occasionally until the mixture just starts to boil.

I usually add both in together for simplicity, but the process goes much faster if you let the water heat up before adding in the sugar.

At this point the sugar should have fully dissolved and the mixture should look clear.

If it has a yellowish hue, that is caused by the sugar starting to caramelize. Heat the mixture at a lower temperature or for a shorter period of time to avoid this.

Remove from heat. If you want to mix in any extracts to flavor the syrup, add them at this stage.

Pour into a separate container to cool to room temperature, then cover and set aside.

How Can It Be Used?

I’m sure it’s no surprise, but my favorite way to use it is to brush it on cake layers!! It adds both moisture and flavor and truly makes any cake irresistible.

I highly recommend leveling each cake layer before adding the syrup, so they can easily absorb the liquid.

You can use a silicone pastry brush or a plastic squirt bottle to generously soak each cake layer with syrup. The entire top of the cake layer should look moist once you’ve added it.

I usually brush my cake layers right before I assemble a cake.

If you want to make and freeze cake layer in advance, I recommend thawing them and then adding the syrup just before you frost the cake.

I use this technique with my death by chocolate cake and it really takes the cake to the next level.

It also tastes amazing in co*cktails and coffee. The sky is really the limit!

How to Store Simple Syrup

Simple syrup should be stored in the fridge, and not kept at room temperature for extended periods of time.

Unflavored syrup can be made in advance and stored in an airtight container in the fridge for up to a month.

However, flavored syrups (especially fruit-flavored) should be used within 2 weeks of when they’re made.

I usually keep mine in a mason jar but any airtight container with a good lid will work great.

Can You Store Simple Syrup in Plastic?

Simple syrup lasts the longest when stored in an airtight glass container, but it can be stored in a plastic container.

Some people store it in plastic squirt bottles to make it easier to pour into jiggers.

This is totally fine, just be sure to cap the tip of the bottle once you’re done using it or wrap the top with plastic wrap to keep it fresh.

Does Simple Syrup Go Bad?

The short answer is yes. You’ll know it has gone bad once it is no longer clear and starts to look cloudy in appearance.

When this happens, it has started to grow mold and should be thrown out.

This can be harder to tell with darker flavored syrups like chocolate or blueberry, so follow the guidelines above and use flavored+n syrup within 2 weeks of when it’s made.

I find it’s super helpful to label my container, so I know how old it is and when I need to use it by.

Does Simple Syrup Need to be Refrigerated?

Yes and no. Refrigerating simple syrup extends its shelf life and slows the future growth of bacteria.

You can keep it at room temperature, but it will go bad much faster.

If you plan use up it up within a few days, it can be stored at room temperature. Otherwise I highly recommend storing it in the fridge or freezer.

Can You Freeze Simple Syrup?

Simple syrup can be frozen! It freezes solid and will stay good frozen for up to 3 months.

If you plan to go this route, use a plastic container rather than a glass container.

Non-tempered glass can break when frozen, and that is a mess none of us want on our hands!

When you’re ready to use it, transfer the container from the freezer to the fridge the night before to let it thaw. Once in the fridge, it should stay good for 2-4 weeks depending on whether it’s flavored or not.

Have a Question I Didn’t Cover?

Hopefully I’ve covered all your questions but if I’ve missed anything please ask additional questions in the comments section below.

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