Winterization Process Guide
This guide outlines the full winterization workflow used to remove fats, waxes, and other solids from crude extracts using ethanol or alkane solvents. It includes safety notes, required materials, filtration steps, dry ice testing, and optional adsorbent scrubbing before or after the first pass distillation.
Link to Winterization Instructions
Quick Facts
- Process Name: Winterization
- Category: SOP / Purification
- Primary Solvents: Ethanol (preferred), n-Heptane, Hexane
- Filtration Media:
- Silica Gel
- Activated Alumina
- Typical Ratio: 1 part crude : 10 parts ethanol (10:1)
- Purpose: Remove lipids, waxes, and impurities before distillation
- Skill Level: Intermediate lab technician
Safety & PPE
- SDS sheets are available for all chemicals used and must be reviewed before beginning.
- Work in a ventilated area or fume hood.
- Use standard PPE for solvent handling:
- Lab coat
- Chemical-resistant gloves
- Eye protection
- Closed-toe shoes
Required Materials & Media
- Silica Gel
- Activated Alumina
- Solvent (choose one):
- n-Heptane
- Hexane
- Ethanol
Winterization Procedure
STEP 1 — Warm the Crude
- Warm crude oil to 30°C to ensure full fluidity.
STEP 2 — Fully Dissolve Crude in Solvent
- Dilute crude in ethanol at a 10:1 ratio (1 L crude : 10 L ethanol).
STEP 3 — Cool to Room Temperature
- Allow the mixture to cool naturally.
STEP 4 — First Filtration (Warm Filtration)
- Filter the crude/solvent solution over Activated Alumina layered on top of Silica Gel using a filter funnel.
STEP 5 — Chill to 0°C
- Cool the solution to 0°C to precipitate fats and waxes.
STEP 6 — Second Filtration (Cold Filtration)
- Repeat filtration through alumina + silica.
STEP 7 — Dry Ice Test (Representational Sample)
- Take a small sample of the winterized solution, add dry ice, and allow bubbling to stop.
STEP 8 — Filter the Sample
- Filter the chilled test sample through the same alumina/silica setup.
STEP 9 — Evaluate Results
- If additional solids are present in the test sample, repeat the dry ice test and filtration on the entire solution.
- If no solids remain, winterization is complete.
At This Point: Two Path Options
- Option A — Pre-First Pass Adsorbent Scrubbing
- (If performing a single-pass distillation, or if you do not wish to process between passes.)
- Option B — Post-First Pass Adsorbent Scrubbing
- Performed in an alkane solution (n-Heptane or Hexane) for better results.
Pre-First-Pass Adsorbent Scrubbing Procedure
STEP 1 — Heat Oleoresin
- Heat the oleoresin to 90°C in a well-ventilated area or fume hood.
STEP 2 — Add T-41
- Add 5% T-41 by weight:
- Example: 1000 g oleoresin : 50 g T-41
- Mix slowly while maintaining 90°C.
STEP 3 — Mix Thoroughly
- Stir the mixture for 20–30 minutes at ≥90°C.
STEP 4 — Cool and Add Carrier Solvent
- Cool mixture to ≈40°C, then add a carrier solvent (choose one):
- Ethanol
- Hexane
- n-Heptane
- Filter through alumina/silica.
STEP 5 — Repeat as Needed
- Repeat Steps 1–4 2 to 3 times depending on color remediation requirements.
- Note: Hardwood Activated Carbon may replace T-41 for the first scrub, especially if multiple scrubs are planned.
- Degumming is recommended before first-pass distillation.
Contact & Support
For support selecting winterization filters, scrubbing media, or solvent equipment:
📞 734-855-4890
📧 support@usalabequipment.com