At What Temperature Does Levulinic Acid Crystallize? Full Lab Data & Safety Guide

After we shared our Israeli client levulinic acid crystallization case study earlier this year, the single most common question we received from formulators, procurement managers, and fellow traders was this: At what exact temperature does levulinic acid crystallize?

It’s a simple question, but the answer has massive implications for your supply chain, storage strategy, and production planning. Get it wrong, and you could end up with a drum of solid raw material, a delayed production run, or even a frustrated client complaint.

After 12 years in cosmetic raw material trade, and hundreds of lab tests on different grades of levulinic acid (CAS 123-76-2) in our in-house R&D facility, we’re sharing the full, unfiltered lab data, the exact crystallization temperatures for every common grade, and the safety and storage rules you need to avoid costly mistakes.

The Exact Crystallization & Melting Point of Levulinic Acid

First, let’s clear up a critical technical distinction that causes endless confusion in the industry: for pure, single-component chemicals, the crystallization temperature (freezing point) and melting point are the exact same temperature.

For high-purity cosmetic-grade levulinic acid, that temperature is 37°C (98.6°F).

This means:

• At temperatures above 37°C, pure levulinic acid will be a clear, stable liquid.
• At temperatures below 37°C, pure levulinic acid will begin to form crystals, and will eventually solidify fully with extended cold exposure.

There is no “magic temperature” below 37°C where crystallization suddenly happens overnight. The speed of crystallization depends on how far the temperature is below 37°C, the purity of the product, and the storage conditions. For example:

• At 30-35°C (just below the melting point): Partial crystallization may occur over 1-2 weeks, with small crystals forming along the edges of the drum.
• At 10-25°C (standard room temperature or winter warehouse conditions): Full, uniform crystallization will occur within 24-72 hours.
• At 0°C or below (freezing conditions): Rapid, dense crystallization will happen in just a few hours.

If you’re already dealing with solidified product and need to confirm it’s still usable, check out our complete troubleshooting guide here.

Lab-Tested Data: How Purity Impacts Levulinic Acid’s Crystallization Temperature

The 37°C benchmark applies only to high-purity levulinic acid. Purity is the single biggest factor that changes the product’s crystallization behavior, and this is where most formulators and traders get caught off guard.

We tested 3 of the most common commercial grades of levulinic acid in our lab, measuring their exact crystallization temperature and behavior. Here’s the full data:

1. 99.5% Cosmetic-Grade Levulinic Acid (Pharma-Eligible)

• Exact Crystallization Temperature: 36.8-37.2°C (narrow 0.4°C range)
• Crystallization Behavior: Uniform, consistent crystal formation across the entire volume of the product. Crystals are fine and homogeneous, and melt completely and evenly when heated back to 37°C+.
• Key Insight: This is the grade we supply to our cosmetic and personal care clients, and the narrow crystallization range is a key marker of its high purity. This is the grade that will crystallize most consistently at temperatures just below 37°C, which is why our Israeli client saw full solidification in winter temperatures.

2. 99% Industrial-Grade Levulinic Acid

• Exact Crystallization Temperature: 35.5-36.8°C (wider 1.3°C range)
• Crystallization Behavior: Slower, less uniform crystallization than cosmetic-grade. Crystals form in clumps along the bottom and edges of the drum first, rather than uniformly across the volume.
• Key Insight: The small amount of residual impurities in industrial-grade levulinic acid act as a freezing point depressant, lowering the crystallization temperature slightly. This grade may not fully crystallize at room temperature for 1-2 weeks, unlike cosmetic-grade.

3. <95% Low-Purity Levulinic Acid

• Exact Crystallization Temperature: 30-35°C (extremely wide, inconsistent range)
• Crystallization Behavior: Erratic, non-uniform crystallization. In many cases, the product will remain partially liquid even at temperatures well below 30°C, with only partial clumping or crystal formation.
• Key Insight: High levels of impurities drastically lower the crystallization temperature, and can even prevent full solidification entirely. If your levulinic acid is solid at temperatures above 37°C, this is a red flag for unexpected contaminants, not high purity.

Other Factors That Change Levulinic Acid’s Crystallization Behavior

Purity and temperature are the primary drivers, but these 3 secondary factors can alter how and when your levulinic acid crystallizes:

1. Humidity & Moisture Exposure

Levulinic acid is highly hygroscopic, meaning it absorbs moisture from the air. Even small amounts of water absorbed through a broken seal or an open drum can:

• Lower the crystallization temperature by 1-3°C
• Cause cloudiness or uneven crystallization
• Increase the risk of microbial growth over time

Rule: Always keep levulinic acid in a tightly sealed drum, and avoid opening it in high-humidity environments.

2. Storage Duration & Temperature Fluctuations

Frequent temperature cycles (warming above 37°C and cooling back below it) will accelerate crystal formation, even if the average temperature is just below the melting point.

For example: A drum stored in a facility that warms to 38°C during the day and cools to 22°C at night will crystallize much faster than a drum stored at a consistent 25°C.

Rule: For long-term storage, keep the temperature consistent, either just above the melting point (to prevent crystallization) or well below it (for stable solid storage).

3. Cross-Contamination With Other Raw Materials

Even trace amounts of other cosmetic raw materials (e.g., glycols, surfactants, other active ingredients) can alter levulinic acid’s crystallization behavior.

Cross-contamination can lower the crystallization temperature, cause uneven clumping, or even prevent crystallization entirely.

Rule: Always use dedicated, clean equipment when handling levulinic acid, and never mix it with other raw materials before your formulation process.

Optimal Storage Temperature to Prevent Unwanted Crystallization

Based on our lab testing and 12 years of real-world client experience, here are our non-negotiable storage temperature recommendations:

1. Liquid Storage (No Crystallization): Store at a consistent 40-45°C in a temperature-controlled hot room or heating cabinet. This is just above the melting point, prevents any crystal formation, and avoids the risk of thermal degradation (which can occur at temperatures above 60°C).
2. Long-Term Solid Storage: If liquid storage is not available, you can store levulinic acid in its solid state at a consistent 15-25°C (room temperature). Solid levulinic acid is extremely stable, and will remain effective for its full shelf life when stored in a sealed, intact drum.
3. Never Store: At temperatures above 60°C (risk of thermal degradation) or below 0°C for extended periods (no safety risk, but can cause extremely dense crystallization that takes longer to melt).

Safety Rules For Handling Crystallized Levulinic Acid

Crystallized levulinic acid is not hazardous, but improper handling can ruin the product or create safety risks. Follow these rules:

• Never open a drum of crystallized levulinic acid and attempt to break up the crystals manually. This introduces contamination risk, and will not speed up melting.
• Always use gradual, controlled heating to melt crystallized product. Never use direct heat, open flame, or microwave heating, which can cause localized overheating and degradation.
• Always keep the drum sealed during heating to prevent moisture absorption and contamination.
• Never heat levulinic acid above 60°C, even to speed up melting. This can cause thermal degradation, alter the product’s odor and color, and compromise its performance in your formulation.

Our step-by-step hot water bath guide is the safest method for melting crystallized levulinic acid, and works for both small lab containers and full 25kg industrial drums.

Regional Seasonal Guidelines (For Global Shipping & Storage)

We work with clients in over 30 countries, and we’ve refined these regional guidelines to help you avoid crystallization surprises during shipping:

• Cold Climate Regions (EU Northern Countries, Canada, Russia): Avoid uninsulated shipping between October and March. Use insulated drum covers, and proactively share melting instructions with clients before shipment arrives.
• Temperate Climate Regions (EU Mainland, USA, Israel, Turkey): Expect crystallization risk between November and February for uninsulated shipments. Room-temperature storage will cause partial crystallization in winter months.
• Tropical Climate Regions (Southeast Asia, South America, Middle East): Minimal crystallization risk for most of the year, but air-conditioned storage may still drop below 37°C, causing slow partial crystallization over time.

Final Thoughts

The exact crystallization temperature of your levulinic acid isn’t just a number on a technical data sheet—it’s a critical detail that shapes your entire supply chain, storage, and production planning.

For high-purity cosmetic-grade levulinic acid, that number is 37°C. But as our lab data shows, purity, storage conditions, and shipping environment all play a role in how and when your product crystallizes.

If you’re unsure about the right storage or shipping strategy for your levulinic acid, or need help interpreting your batch’s CoA data, drop a comment below, or reach out to our technical team for a customized regional shipping and storage guide.