How Long Does Rosemary Water Last Unrefrigerated? Storage Tips

The Shelf Life of Rosemary Water at Room Temperature

Rosemary water has become a popular DIY hair care ingredient thanks to its purported ability to stimulate hair growth, add shine, and improve scalp health. Videos demonstrating how to make refreshing rosemary hair rinses have gone viral on TikTok and YouTube. However, many homemade beauty preparations like herb-infused waters don't contain preservatives to extend their shelf life.

So, how long does rosemary water last at room temperature? Properly stored, rosemary water can last up to 5 days without refrigeration before mold growth and bacteria make it unsafe to apply to hair or skin. Following best practices when preparing and storing rosemary water can help preserve its aromatic, antimicrobial properties.

Why Rosemary Water Needs Refrigeration

Like most plant materials and herbal infusions, rosemary water provides ideal conditions for microbes like mold and bacteria to multiply quickly at room temperature. Key factors that contribute to spoilage include:

• Water activity (aw) - the presence of water itself allows microorganisms to grow.
• Nutrients - compounds from the rosemary provide food for contaminants.
• Oxygen - headspace in containers enables aerobic bacteria.

Refrigeration slows microbial growth by cooling the rosemary water and limiting water activity. The optimal storage temperature for herbals waters falls between 38F and 45F (3C and 7C).

Signs of Spoilage

How can you tell if rosemary water has exceeded its room temperature shelf life? Signs that stored rosemary water has gone bad include:

• Cloudiness
• Visible mold
• Yeasty smell
• Rotten odor
• Fizzing/bubbling

If you observe any indications of contamination, err on the side of caution and discard the rosemary water.

Maximizing the Shelf Life of Rosemary Water

You can take several steps when preparing and storing rosemary rinse to extend its shelf life to up to 1 week refrigerated or up to 5 days at room temperature:

Sanitize Equipment

Disinfect any pots, utensils, funnel or bottles you use to make and store rosemary water to prevent inadvertent contamination:

1. Wash equipment in hot, soapy water first.
2. Rinse thoroughly.
3. Sanitize by immersing items in boiling water for 10 minutes.
4. Air dry fully before using.

Use Pure Ingredients

Rinse fresh rosemary under cold running water to remove dirt, pesticides or other residues that could introduce microbes or decay compounds.

Stir While Infusing

Actively stirring rosemary in hot water during the infusion process helps extract more bioactive compounds from the leaves. More efficient extraction yields rosemary water with higher concentrations of beneficial antioxidants and antimicrobial essential oils.

Steep Properly

A standard infusion ratio for herb-infused waters is:

• 14 cup lightly packed fresh herb
• 4 cups water

Steep rosemary for 30 to 60 minutes to fully extract essential oils and phenolic antioxidants before straining out the plant material.

Cool Quickly

Chilling rosemary water rapidly after brewing also helps limit microbial growth. Avoid leaving the liquid at room temperature to slowly cool down.

Use Sterilized Containers

Store strained rosemary water in sanitized, air-tight bottles or jars, leaving as little headspace as possible. Glass and food-grade plastic with leakproof lids work best. Make sure containers are completely dry before filling.

Refrigerate Promptly

Once rosemary water reaches room temperature, transfer containers to the refrigerator right away. Ideally, refrigerate infused herb waters within 2 hours of preparation.

Alternatives to Refrigeration

What if you don't have access to refrigerator storage? Some alternative methods can extend the shelf life of fresh rosemary water, although not as long as refrigeration:

Frozen Ice Cubes

Pour freshly prepared rosemary water into an ice cube tray and freeze. Once frozen, transfer herb cubes to an airtight freezer bag or container. Frozen rosemary water ice cubes last up to 6 months frozen.

Vinegar

Add 2 tablespoons apple cider vinegar or white vinegar per 4 cups rosemary water as a natural preservative. The vinegar acidifies the liquid to inhibit bacteria. Vinegar-preserved rosemary water will last up to a month stored in the pantry.

Vodka

Mixing distilled spirits like vodka or witch hazel helps stabilize rosemary water by lowering water activity. Add 2 oz vodka or witch hazel per 4 cups rosemary water. Vodka- or witch hazel-preserved blends last 2 to 3 months when sealed in cool, dark storage.

Citric Acid

As a final alternative, 1/2 teaspoon citric acid powder per 4 cups rosemary water also acidifies the solution to discourage spoilage. Citric acid-treated blends stay fresh for 15 to 30 days unrefrigerated.

Get the Most Out of Your Rosemary Water

While rosemary water smells delicious and makes hair feel incredibly soft initially, it won't remain stable and effective forever. Follow the best practices outlined here to safely prepare and store your batches for maximum longevity.

Prioritize refrigeration and proper sanitation whenever possible to keep homemade rosemary water fresher for longer. But also be vigilant about discarding batches past their prime to avoid health risks or hair damage from rancid solutions. With reasonable care and caution, you can safely unlock the purported benefits of rosemary water for scalp and strands.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment regimen.