Why did my monk fruit simple syrup crystallized?

Monk fruit simple syrup is a popular natural sweetener that can be used as a substitute for sugar in drinks, baked goods, and more. It is made by boiling monk fruit extract with water to create a concentrated, sweet syrup. While monk fruit syrup has many benefits over regular sugar, one common problem people run into is the syrup crystallizing and hardening in the bottle over time. There are a few key reasons why monk fruit syrup may crystallize.

High Monk Fruit Extract Concentration

Most simple syrup recipes call for equal parts sugar and water. However, with monk fruit syrup, the amount of extract used is much lower than the amount of water since the extract is intensely sweet. Using too much monk fruit extract can lead to crystallization. The high concentration of sweet compounds causes the syrup to become oversaturated and the monk fruit molecules will crystallize out of solution over time.

As a general rule, monk fruit extract should be used sparingly in simple syrup recipes. Start with a very small amount, stir vigorously to incorporate, and only add more if needed. Using too much monk fruit extract is one of the biggest reasons behind crystallization issues.

Improper Dissolving of Monk Fruit Extract

Monk fruit extract is not water-soluble like regular granulated sugar. Therefore, it takes more effort to properly dissolve the extract into simple syrup. If the monk fruit extract is not completely dissolved when making the syrup, it can recrystallize out of solution over time.

To help avoid this, bring the water to a boil first before adding in the monk fruit extract. Once added, stir continuously for several minutes to ensure the extract is fully dissolved into the syrup. Boiling helps breakdown the monk fruit particles while vigorous stirring prevents clumping.

Adding Monk Fruit Extract When Syrup is Cool

Another dissolving-related reason monk fruit syrup may crystallize is if the extract is added when the syrup is no longer hot. Monk fruit particles will not dissolve as readily in cooler liquid. For best results, remove the syrup from heat and stir in the monk fruit extract immediately while still very hot. This helps ensure the extract fully melts into the syrup.

Letting the simple syrup cool down before adding in the monk fruit extract increases the chances of the particles staying crystallized. Always add in the monk fruit when the syrup is still boiling hot.

Changes in Temperature

Simple syrup is sensitive to changes in temperature. Storing monk fruit syrup in places that experience temperature fluctuations can lead to crystallization over time. For example, if you move the container back and forth between a hot spot (like next to the stove) and the refrigerator, this can cause monk fruit particles to crystallize out.

Try to store finished monk fruit syrup in a cool, consistent environment. Avoid temperature swings by keeping it in the refrigerator or pantry. Fluctuations between hot and cold temperatures make crystallization more likely.

High Fructose Corn Syrup Content

Some monk fruit extracts contain high fructose corn syrup as a bulking agent. High fructose corn syrup has a molecular structure that makes it prone to crystallizing, especially in high concentrations. Check your monk fruit extract ingredients and look for ones without added sugars or corn syrup.

You can also make your own DIY monk fruit extract by mixing monk fruit with warm water and straining out the solids. This will contain only pure monk fruit without additives that can recrystallize.

Exceeding Shelf Life

Over time, almost any simple syrup will eventually crystallize as the water evaporates and the sugar concentration increases. Monk fruit syrup tends to have a shorter shelf life than traditional sugar syrup before this occurs. Most monk fruit syrups stay fresh for 2-3 months when properly stored.

If your syrup has been stored for longer than that, especially if it’s been exposed to temperature changes, crystallization is very likely. For the longest shelf life, make smaller batches of monk fruit syrup and use within a couple months.

Insufficient Boiling

Failing to boil the monk fruit syrup long enough can also set it up for crystallization later on. Syrup should be boiled for 2-3 minutes minimum to concentrate the solution and dissolve any particles. Quickly heating the mixture without adequately boiling can leave undissolved monk fruit extract in the syrup.

Be patient and let the monk fruit syrup come to a full rolling boil for a few minutes when making it. This helps prevent crystallization issues down the road.

Methods to Prevent Crystallization

Here are some tips to help prevent monk fruit simple syrup from crystallizing:

  • Use a minimal amount of monk fruit extract – start with 1/8 tsp per 1 cup water
  • Bring water to a boil before adding extract
  • Stir vigorously as you add the monk fruit extract
  • Boil for 2-3 minutes after adding extract
  • Store in air-tight container in refrigerator
  • Use within 2-3 months
  • Avoid temperature fluctuations
  • Make small batches for freshness

Fixing Crystallized Monk Fruit Syrup

If your monk fruit syrup has already crystallized, there are a couple of ways to try and resuspend the sugar into solution:

  1. Place the jar of crystallized syrup in a pot of warm water over low heat. The indirect heat will slowly melt the crystals without scorching the syrup.
  2. Alternatively, place the jar in the microwave and heat in short increments, stirring in between, until crystals dissolve. Take care not to overheat.
  3. You can also try adding a small amount of liquid like water or alcohol to dilute the syrup and dissolve the crystals.

If these methods don’t work, you can reboil the syrup. Pour it into a pot over medium heat, add a splash of water, and bring to a gentle boil while stirring frequently. This should redistribute the sugar back into solution.

Keep in mind that fully crystallized syrup may need to be discarded and a fresh batch made for best results.

Does Crystallization Affect Safety or Quality?

When monk fruit syrup crystallizes, it does not make it unsafe to consume or lessen the quality. It more affects the texture and appearance. The syrup may become gritty with a grainy mouthfeel once crystallized. It also can form into a solid, hardened block.

Safety-wise, crystallized monk fruit syrup is still edible and contains no toxins or dangers. The sweetness and flavor also remains the same when dissolved into drinks or recipes. It only impacts the smoothness of the syrup itself.

So while crystallization may be frustrating and make the syrup visually unappealing, it does not negatively impact the safety profile or make the syrup go bad.

Storing Monk Fruit Syrup Properly

Here are some tips for properly storing monk fruit syrup to increase shelf life and prevent crystallization:

  • Store in a tightly sealed glass jar or bottle
  • Keep in the refrigerator after opening
  • Wipe down and clean rim/lid of container before sealing to prevent growth of mold
  • If crystallization occurs, gently heat jar in warm water bath to resuspend
  • For long-term storage, keep monk fruit syrup in the freezer
  • Freeze syrup in ice cube trays or muffin tins, then transfer to an airtight freezer bag
  • Thaw frozen syrup in the refrigerator before using

With proper storage techniques, monk fruit syrup can maintain its fresh quality and avoid crystallization issues.

Troubleshooting Crystallized Monk Fruit Syrup

Here is a troubleshooting guide if your monk fruit simple syrup crystallizes:

Issue Potential Cause Solution
Gritty texture Insufficient dissolving of monk fruit particles during syrup preparation Reheat syrup gently to dissolve crystals, use boiling water when preparing syrup in the future
Hardened sugar clumps Monk fruit extract concentration is too high Dilute syrup with small amounts of warm water until crystals dissolve
Crystals around rim of jar Fluctuating storage temperatures Store syrup in refrigerator consistently, avoid temperature changes
Syrup crystallizes rapidly Shelf life has been exceeded Make syrup in smaller batches and use within 2-3 months
Whole batch fully hardened Prolonged storage, old syrup Discard and make a fresh batch of syrup

With some troubleshooting, you can often resuspend crystallized monk fruit syrup by gently heating and stirring the mixture. However, hardened syrup may need to be discarded and replaced with a freshly made batch.

Frequently Asked Questions

Is crystallized monk fruit syrup safe to ingest?

Yes, crystallized monk fruit syrup is still safe to consume. The crystals are simply the natural sweet compounds solidifying out of solution. There are no safety concerns.

What is the best way to liquefy hardened monk fruit syrup?

Gently heating the jar in a warm water bath is the safest way to melt monk fruit crystals without risk of burning or scorching the syrup. Stir frequently until the crystals have fully dissolved.

Should I add corn syrup to my monk fruit syrup to prevent crystallization?

No, avoid adding corn syrup as it can actually encourage crystallization over time. Use pure monk fruit extract and minimal ingredients for the most stable syrup.

Can I freeze monk fruit syrup to prevent crystals?

Yes, freezing is a great long-term storage method for monk fruit syrup. Freeze in ice cube trays or muffin tins, then transfer to an airtight freezer bag.

What ratio of monk fruit extract to water is best?

A ratio of 1/8 teaspoon monk fruit extract per 1 cup water is a good starting point. Add more extract gradually if you desire a sweeter syrup.


Monk fruit syrup is prone to crystallization due to its molecular composition and solubility challenges. By using the proper ratio of extract to water, sufficiently dissolving the extract, and avoiding storage temperature fluctuations, you can minimize the chances of crystals forming.

If your syrup does crystallize, gently reheating the jar in a water bath can often reliquefy the mixture. Take care to prepare and store monk fruit syrup properly and you can enjoy this healthy sweetener while avoiding frustrating crystals.

Leave a Comment