Simple syrup, also known as bar syrup or sugar syrup, is an ingredient commonly used in cocktails and other beverages. It is made by dissolving sugar into boiling water to create a syrup. Simple syrup is valued by bartenders and mixologists because the sugar is already dissolved, making for faster, easier mixing in drinks. However, an opened bottle of simple syrup won’t last forever. So how long can you leave simple syrup out unrefrigerated before it goes bad?
What is simple syrup?
Simple syrup contains just two ingredients – sugar and water. To make simple syrup, sugar is dissolved in heated water and then cooled. The typical ratio is 1:1 – one part sugar to one part water. For example, you would combine 1 cup of granulated white sugar with 1 cup of water. The mixture is heated and stirred until the sugar fully dissolves. Then it is left to cool before using or storing. The resulting syrup has a thin, pourable consistency.
Simple syrup is clear and flavorless, allowing the flavors of other ingredients to shine. It acts as a sweetener and solubilizer in cocktails, coffees, teas, lemonades, and other beverages. The dissolved sugar incorporates seamlessly, avoiding a gritty texture from undissolved granules. Simple syrup also softens flavor. The viscosity helps mellow bitterness and acidity.
There are variations on simple syrup as well. You can make a rich simple syrup using a 2:1 ratio of sugar to water. Other flavors can be infused into the syrup by steeping ingredients like herbs, spices, fruit, and more. But the basic simple syrup formula is an equal ratio of sugar and water.
Does simple syrup need to be refrigerated?
Refrigeration extends the shelf life of simple syrup by slowing down microbial growth and chemical reactions. The ideal storage temperature is below 40°F. However, refrigeration is not strictly necessary if the syrup will be consumed quickly.
Simple syrup contains a large percentage of sugar. The high sugar concentration helps prevent spoilage by bacteria and mold, even at room temperature. With an equal 1:1 sugar-to-water ratio, simple syrup is about 70% sugar. The sugar binds with water molecules, leaving less moisture available for microbes to thrive.
However, over time, the sugars will start to break down. Exposure to heat and oxygen degrades the syrup. It can oxidize, evaporate, ferment, or grow mold. Refrigeration slows this process.
How long does simple syrup last unrefrigerated?
The exact shelf life depends on storage conditions like temperature, air exposure, and container type. But generally, simple syrup can last:
- Refrigerated: Up to 1 month
- Room temperature: Up to 2 weeks
For maximum shelf life, store simple syrup in an airtight container in the refrigerator. An opened bottle will keep for 4-6 weeks. When left out at room temperature, syrup is best consumed within 1-2 weeks. Warm conditions shorten the duration.
How to tell if simple syrup has gone bad
Check simple syrup for the following signs of spoilage:
- Change in texture: Fresh simple syrup has a smooth, thin, pourable consistency. Spoiled syrup may be stringy, thick, or chunky.
- Cloudiness: Syrup gradually darkens with age. Discoloration and cloudiness indicate stale syrup.
- Crystal formation: Sugar crystals may recrystallize as the syrup deteriorates. Crystals stick to the bottle and float in the liquid.
- Fermentation bubbles: Bubbles or froth means yeast or bacteria has grown.
- Mold growth: Mycelium, fuzz, or slimy texture signals mold.
- Off odors: Syrup loses its fresh, neutral smell. Rancid, sour, or rotten scents point to spoilage.
An actively fermenting or carbonated bottle of simple syrup may push up and bulge at the sides. If you see any signs of damage, it is best to discard the syrup.
Does simple syrup go bad or just crystallize?
Both! Simple syrup can both spoil due to microbial growth or chemical reactions and crystallize due to the breakdown of sugars.
As simple syrup ages and begins deteriorating, sugar molecules may come out of solution and reform into crystals. This recrystallization gives the syrup a crunchy, gritty, grainy texture. Sugar crystallization alone does not necessarily mean the syrup has spoiled. It is still safe to consume if it tastes normal otherwise.
However, simple syrup can also grow mold and bacteria over time. Yeasts digest sucrose into glucose and fructose, producing carbon dioxide and ethanol. This fermentation causes bubbling and alcohol formation. Mold can create cottony mycelium or furry patches on the syrup’s surface. Other microbes cause unpleasant odors, taste, and appearance changes.
While crystallization alone is not hazardous, it can be paired with microbial contamination. So if syrup shows signs of crystallization, it should be checked closely for other signs of spoilage before use.
Can spoiled simple syrup make you sick?
Consuming spoiled simple syrup can potentially cause foodborne illness. Mold and bacterial growth pose the biggest risks. Symptoms may include nausea, vomiting, diarrhea, and upset stomach. The level of risk depends on the type of contaminant and the individual’s sensitivities.
Fermented simple syrup contains ethanol, so it may have intoxicating effects if enough is consumed, though likely not at dangerous levels.
While crystallized syrup on its own is not harmful, the sugar crystals could scratch the throat or make swallowing difficult at high concentrations. The safest option is discarding any simple syrup that shows signs of deterioration.
How to store simple syrup properly
Follow these tips for maximizing simple syrup’s shelf life:
- Use sterilized containers and equipment. Sanitize bottles, funnels, and jars before use to avoid introducing bacteria.
- Prepare a small batch size. Don’t make more than you will use in a month.
- Fill the storage container to the very top. This minimizes air exposure.
- Refrigerate after opening. Keep syrup chilled at 34–40°F.
- Store in airtight bottles or jars. Use containers with an airtight lid or seal.
- Add a splash of vodka or other high-proof spirit as a preservative (optional). The alcohol inhibits microbial growth.
- Freeze for long-term storage. Frozen syrup lasts indefinitely.
Avoid introducing water into the container. Humidity causes dissolution and recrystallization. Use dry, sterile utensils for removing syrup. Keep the lid sealed except when scooping out syrup.
Can you reuse simple syrup?
Leftover simple syrup from a cocktail mixer can be reused. Transfer any remaining syrup from the mixing glass, shaker, or bottle back into the storage jar. Ensure containers are kept closed and refrigerated between uses.
Avoid mixing fresh and old syrup together. This introduces contaminants and reduces shelf life. Instead, finish up one batch of syrup before opening a fresh container.
Also beware of dilution. Adding water from shaken drinks or melted ice decreases syrup concentration. Reused simple syrup may need to be boiled down to counteract dilution.
Regularly sanitize equipment and containers to avoid contamination when reusing syrup. Discard any syrup that shows signs of mold, fermentation, or crystallization.
How to revive crystallized simple syrup
You may be able to save crystallized simple syrup by remelting it:
- Pour the syrup into a saucepan and warm it over medium heat. Stir periodically to dissolve sugar deposits.
- Bring to a brief simmer, then remove from heat. Avoid boiling to prevent evaporation.
- Pour syrup through a strainer to remove any remaining crystals.
- Let cool before transferring back to the storage container.
- Discard syrup if it smells odd or shows any sign of mold.
Straining helps improve consistency and shelf life. But remember that remelting is a temporary fix – the syrup may recrystallize faster next time. Consume revived syrup quickly.
How to make simple syrup last longer
Proper preparation and storage helps maximize shelf life. Here are tips for making simple syrup last:
- Start with hot simple syrup. Heating the water to dissolve the sugar also kills potential microbial contaminants.
- Substitute brown sugar, honey, or maple syrup. These have antimicrobial properties.
- Add citrus juice or alcohol as a preservative.
- Use sterilized containers to avoid introducing bacteria.
- Refrigerate after opening. Keep bottles sealed when not in use.
- Freeze for long-term storage.
A stronger syrup ratio results in a higher sugar concentration for increased preservation. A 2:1 sugar-to-water ratio makes rich simple syrup, which lasts somewhat longer than standard 1:1 simple syrup. But it still requires refrigeration after opening.
Conclusion
Simple syrup can be left at room temperature for 1-2 weeks before spoiling if stored in a tightly sealed container. Refrigeration is ideal for lasting 4-6 weeks. Signs of spoiled syrup include changes in texture, appearance, aroma, and the presence of molds or crystals. Discard any syrup that seems off. Following proper sanitation, preparation, storage, and handling practices helps maximize shelf life.
