How We Extract Everything That Matters

The method used to pull cannabinoids and terpenes from hemp decides everything about what ends up in the bottle. Here is what actually separates one method from another — and why PurBlend built its own standard.

The Short Version

Hemp spends months building a precise, complex chemical profile — the exact blend of cannabinoids, terpenes, and supporting compounds that makes each strain what it is. Most extraction methods apply heat, extreme pressure, or harsh solvents that strip that profile down to something generic. The chart below shows what each method actually captures. The wider the coverage across the “Full Spectrum Oil” columns — and the cleaner the stop before the “Fillers” columns — the better.

PBX-Standard R134a captures the full spectrum of oil-soluble compounds while leaving water-phase fillers behind.

The Four Methods, Compared

CO2 — The Pressure Problem

CO2 extraction runs at pressures near 8,800 psi. At that point the CO2 becomes a supercritical fluid that dissolves cannabinoids — but it cannot pull terpenes and cannabinoids efficiently in the same pass. Two separate runs are needed, then the outputs are recombined with ethanol post-processing. The strain-specific character gets diluted along the way.

Hydrocarbon — The Flammability Problem

Butane and propane dissolve cannabinoids well, but they are flammable, they create scaling limits for larger production, and they leave plant waxes that require an aggressive de-waxing step — usually cold ethanol, which adds another solvent exposure and another chance for terpene loss.

Ethanol — The Heat Problem

Ethanol is efficient and inexpensive at scale, which is why it is everywhere. But it boils at 176°F, and terpenes begin to break down in that same range during evaporation. Ethanol also denatures the oil during processing and loses 15–20% of solvent per run. The result is a compromised terpene profile at a higher production cost.

Aerosol — The PBX Difference

The PBX Standard runs on the Comerg patented aerosol platform, using a liquified gas at low pressure and low temperature — conditions that mimic the plant’s natural environment instead of fighting it. R134a is a non-polar, non-flammable, non-toxic gas that does not react with plant components in the water phase. It selectively draws out terpenes and heavier resins, leaves the fillers behind, and is fully reclaimed from the finished oil, imparting no flavor or tint. No winterization. No residual contamination.

How PBX Works

Three controlled stages, each with a defined temperature and pressure — documented and repeated identically on every batch.

The PBX-Standard aerosol extraction system.

PBX in Motion

Post-extraction refinement — full-spectrum oil separating during distillation.

The Deep Dive

Closed-Loop Systems

Solvent-based extraction is done in a closed-loop system — an extractor, condenser, collection vessel, vacuum pumps, and chillers, all sealed. The sealed design lowers fire and explosion risk and lets the operator hold a precise temperature and pressure so the solvent bonds with the target compounds without damaging them. It is the safe, repeatable foundation the PBX Standard is built on.

The “Solventless” Myth

Mechanical methods like rosin pressing and bubble hash are marketed as solventless, but they come with a catch: there is no selectivity. The output is a mix of wax, cannabinoids, terpenes, and chlorophyll that still has to be refined before it is usable. Pressing under heat melts and separates the oil but converts cannabinoids and drives off most terpenes, while keeping 5–20% waxy content. Winterizing to fix that strips the remaining terpenes. By the end, the “solventless” advantage is gone.

Post-Processing and Residual Solvents

Most extraction methods need post-processing — winterization, filtration, distillation, remediation — each usually a separate machine. And any solvent used has to be removed completely to meet residue regulations. This is where liquified gas wins: the gas is introduced and reclaimed cleanly, without leaving a residue. It matters which gas, though. Highly oxidative CO2 can create undesired acids; butane can hydrogenate oils and leave an aftertaste. The ideal is an inert gas with low miscibility in oils and water that does not alter the natural plant molecules and is not present in the final product. R134a fits that description.

Terpenes, and Why They Are Hard to Keep

Terpenes are the aromatic compounds behind a strain’s character. They are highly volatile — they evaporate at ambient temperature, which is exactly what makes them so easy to lose during extraction and post-processing. There are over 3,000 terpenes in nature, and cannabinoids themselves share a related structure. Capturing cannabinoids and terpenes together, intact, is the only way to preserve the plant’s true profile — and only a few methods can do it.

Recent research underscores how much complexity is at stake. In a 2021 study in ACS Omega, Oswald and colleagues mapped the chemical diversity of cannabis and identified classes of aroma compounds beyond the familiar terpenes — including esters, alcohols, aldehydes, and a newly described group of volatile sulfur compounds (VSCs) responsible for the sharp citrus and tropical notes in certain varieties. The takeaway is that the compounds a lab typically tests for are only part of what defines a plant’s true character. Preserving the whole spectrum — not just the headline terpenes — is what full-spectrum extraction is really about.

What Good Is CBD Your Body Can’t Absorb?

Extraction is only half the story. What good is a perfect full-spectrum oil if the body can’t absorb it? That second half — bioavailability — is where most CBD products quietly fall short.

Cannabinoids are naturally oil-based, and oil and water don’t mix. The human body is mostly water, so oil-based cannabinoids absorb slowly and incompletely — often only a fraction of what’s on the label actually reaches your system. Most products just add more to compensate, raising cost without solving the real problem.

PurBlend took a different route: we developed techniques to emulsify PBX-Standard oils into a water-compatible format, so cannabinoids absorb faster and more completely — delivering more of what you paid for. Read the science behind water-soluble cannabinoids →

Our flagship product, ReLiever Body Lotion, is built on this dual-delivery system — water-soluble cannabinoids for fast absorption, plus oil-based cannabinoids for a longer-lasting effect. Fast-acting and long-lasting in one formula, it’s the clearest example of the PBX Standard working from extraction all the way through to how it reaches your skin. Shop ReLiever →

See It in Every Product

Every batch is third-party tested by an independent ISO 17025 accredited lab, with a Certificate of Analysis on every product page.

• R134a Extraction vs CO2 Extraction
• The PBX-STANDARD Defined
• Natural vs. “Nature Identical”