CBD Guides

Winterised CBD oil: what it is and why it matters

By the Honest CBD Co team · 19th August 2026 · Updated 1st October 2026

Winterised CBD oil is crude cannabis extract that’s been washed in chilled ethanol to strip out fats, waxes and lipids, leaving a clearer, more concentrated concentrate behind. Two things matter to you as a buyer:

Check clarity and purpose. A winterised oil should look clean, and the listing should say what the winterisation was for, not just repeat “full spectrum”.
Know who made it. Winterisation is a process claim, so it means more when you know who is behind the bottle. The process itself is well documented by specialists such as Cannalabs Consulting.

Key Takeaways

Winterised CBD oil delivers higher measured cannabinoid purity and cleaner performance by removing waxes and lipids through an ethanol wash, chill, and filtration sequence.

Point	Details
Winterisation raises purity	Lipid removal of roughly 85 to 95% can lift cannabinoid concentration from around 55 to 65% up to 80 to 90%.
Polishing filtration matters most	A final 5-micron (or finer) pass is what separates genuinely clear oil from merely acceptable oil.
Know who made it	A winterisation claim means more when there is an established producer behind it who can tell you how the oil was made.
Not every product needs it	Skip winterisation logic for oils already distilled or isolated, since the wax is already gone.
Honest CBD Co	A family business in Bolton making small-batch CBD oil in the UK since 2018, with CBD lab-tested at source and certificates available on request.

This article is general information, not a substitute for advice from a qualified doctor. Consult a qualified healthcare professional about your own circumstances before acting on anything here.

What does winterisation actually mean for CBD oil?
How is CBD oil actually winterised, step by step?
What are the benefits and drawbacks of winterised CBD oil?
Does winterisation change cannabinoid and terpene content?
What safety checks matter for winterised CBD oil?
How can you tell if a CBD oil has been winterised?
Why does the final polishing filter matter so much?
Where Honest CBD Co fits into this
Sources

What does winterisation actually mean for CBD oil?

Winterisation is the purification step that follows raw extraction, not the extraction itself. Crude extract gets dissolved in high-proof ethanol, chilled until the fats and waxes solidify, then filtered out before the solvent is recovered. It sits between crude extraction and finished products like distillate or isolate.

If your starting extract comes from CO2 rather than ethanol, winterisation is often still needed, since CO2 pulls waxes and lipids too. Once you’ve gone further and distilled the oil, though, winterising again is largely redundant. The process removes:

Plant waxes and lipids
Excess fats
A good amount of chlorophyll

It does not remove THC. That only happens through distillation or targeted isolation afterwards, so a winterised oil sold as “full spectrum” will still carry the same trace cannabinoid profile it started with, just cleaner around it.

How is CBD oil actually winterised, step by step?

The process follows a fairly consistent sequence across producers, whether they’re working with hemp‑derived crude or BHO‑style extract.

Dissolve the crude in high-proof ethanol, typically at a ratio of around 10:1 solvent to crude as a minimum, according to protocols set out by Cannalabs Consulting.
Chill the mixture to roughly minus 20°C, colder still for waxier BHO‑type crude.
Hold at that temperature for 12 to 24 hours, letting fats and waxes solidify out of solution.
Coarse filter to pull out the bulk of the precipitated wax.
Polish filter through finer media to catch what the coarse pass missed.
Recover the solvent using a rotary evaporator or vacuum purge, leaving concentrated, wax-reduced extract behind.

Done correctly, this removes an estimated 85 to 95% of lipids and can lift cannabinoid purity from around 55 to 65% up to 80 to 90%, per Cannalabs Consulting’s figures. Newer automated systems have compressed some of these hold times from roughly 24 hours down to 3 to 6 hours, as Boulder Creek Technologies has noted with their equipment.

Pro Tip: Coarse filtration handles most of the visible wax, but a final polish through 5-micron media (sometimes finer) is what separates a hazy concentrate from a genuinely clear one. Skip it, and cloudiness often persists even after everything else has gone right.

Shop the product

Full Spectrum CBD Oil

10% (1,000mg) or 20% (2,000mg) per 10ml bottle, about 5mg or 10mg of CBD per drop. Made in small batches in Bolton since 2018.

From £25.99Shop now

What are the benefits and drawbacks of winterised CBD oil?

The upside is straightforward, and it’s why winterisation has become the default first purification step for medical and consumer concentrates alike, according to Buffalo Extraction Systems.

Clearer, more visually consistent oil
Cleaner taste, with less waxy or plant-heavy flavour
Less coil fouling in vape products and less gunk to deal with during distillation
More stable, predictable dosing over the product’s shelf life

It isn’t free, though. Ethanol costs money and needs proper recovery and disposal. Some terpene loss is common during the wash and solvent removal stages. Run the ratios too lean, below roughly 8:1 ethanol to crude, and you risk cannabinoids co-precipitating with the wax layer, losing product you meant to keep. Winterisation earns its cost when the oil is heading into vape products, tinctures sold on clarity, or feedstock for further distillation. Skip it for material that’s already been distilled or isolated.

Does winterisation change cannabinoid and terpene content?

Winterisation doesn’t alter cannabinoid chemistry. What changes is the measured concentration, because stripping out inert waxes and lipids means the remaining cannabinoids make up a larger share of what’s left. A crude extract testing at 60% CBD might read closer to 85% after winterisation, not because more CBD was created, but because everything diluting it was removed.

Terpenes fare less well:

Some terpene loss is normal during the ethanol wash and solvent recovery stages
Producers wanting a specific aroma or flavour profile sometimes reintroduce terpenes after processing
A Certificate of Analysis should reflect all of this: a higher cannabinoid percentage, low or absent wax and lipid markers, and a clean residual solvent result

What safety checks matter for winterised CBD oil?

Solvent removal is where safety and quality overlap. A properly winterised oil has been through rotary evaporation or vacuum purge to strip the ethanol out, and the resulting COA should confirm residual solvent levels sit within an accepted range. Toxicology literature on solvent exposure, available via PubMed Central, underlines why this recovery step isn’t optional.

A trustworthy COA should cover:

Residual solvents
Heavy metals
Microbial contamination
Full cannabinoid profile
Wax and lipid indicators, where the lab reports them

Worth checking: a “clear” or “winterised” claim should come with something behind it, whether that is lab data, a clear explanation of the process, or simply a producer with a long enough track record to ask. Vague or unexplained solvent figures are the one genuine warning sign.

How can you tell if a CBD oil has been winterised?

A few quick checks tell you most of what you need to know before you buy.

The oil looks clear at room temperature, not cloudy or waxy
The listing explicitly mentions winterisation, ethanol washing, or a stated filtration micron size
Any clarity or purity claim on the listing is backed by lab data, not just asserted
The COA shows a cannabinoid percentage that’s climbed relative to typical crude, with no wax markers flagged

If none of that is clear from the listing, just ask. A producer who knows their own process will happily talk you through it.

Why does the final polishing filter matter so much?

Coarse filtration clears out the bulk of precipitated wax, but it leaves behind fine particulate that keeps oil looking slightly hazy. A final pass through 5-micron media, sometimes finer, is what pushes clarity the rest of the way.

Pro Tip: When comparing suppliers, ask specifically what micron rating their final polish uses. Anything coarser than 5 microns tends to leave visible haze behind, even after a technically correct wash and chill cycle.

When does winterised oil make the most sense?

For vaping, for tinctures sold on visual clarity, and as feedstock heading into further distillation, winterised oil is worth the extra processing step. If you’re buying something already distilled or isolated, the wax has already gone, so there’s nothing left to winterise.

Where Honest CBD Co fits into this

We are a husband-and-wife business in Bolton, and we have been making CBD in the UK in small batches since 2018. We are not an extraction plant, so we will not pretend to walk you through our own winterisation rig. What we can tell you is the part that matters: the CBD we use is lab-tested at source, and we are happy to share the certificates with anyone who is interested.

If you are shopping rather than researching, our Full Spectrum CBD Oil comes in 10ml bottles at 10% (1000mg) for £25.99 and 20% (2000mg) for £37.99, and the wider CBD oils category lets you compare strengths and formats side by side. We answer our own emails, so ask us anything you like.