Cannabis oil — the complete guide

TL;DR

• Coconut / MCT: highest yield (~ 85% saturated fat).
• Olive oil: fine flavour, ~ 60% yield.
• Sous-vide 95 °C, 4 h: odour-free, no terpene loss.
• For capsules: MCT oil into empty veggie caps (pipette).

Why fat extracts cannabinoids

THC and CBD are lipophilic (logP > 6). Practically insoluble in water, highly soluble in triglycerides. The more saturated the fat, the tighter the binding and the better oral bioavailability.

Oil choice: coconut, olive oil or rapeseed oil

Coconut oil contains a high proportion of medium-chain triglycerides and binds cannabinoids particularly well; it is solid at room temperature, which makes portioning easier, and has a long shelf life. Olive oil extracts slightly less efficiently, but brings flavor and is suitable for cold applications such as dressings — just not for high-heat searing. Rapeseed oil is neutral and inexpensive, but oxidizes more quickly and should be stored in a dark, cool place.

The extraction itself follows the same logic as with butter: decarboxylated material, 70 to 90 °C, two to three hours with occasional stirring, then strain. A sous-vide bath or a slow cooker with a keep-warm function maintains the temperature more reliably than any stovetop and significantly reduces the odor.

• Coconut oil: highest binding, solid at room temperature, easy to portion
• Olive oil: flavorful, ideal for cold applications
• Rapeseed oil: neutral and inexpensive, oxidizes faster
• Sous-vide or slow cooker instead of a stovetop for stable temperature

Shelf life, storage and labeling at home

Light, oxygen and heat are the three enemies. Stored in a cool place in a dark glass bottle, canna-oil remains stable for around twelve months; longer in the refrigerator. More important than the shelf life is the labeling: date, material used, estimated content per teaspoon. Unlabeled oil bottles in the kitchen cupboard are the most common reason for accidental consumption by roommates — and with children and pets, this is precisely the real risk.

Swiss classification: Under food law, cannabinoid-containing foods are classified as novel foods and require authorization from the Federal Food Safety and Veterinary Office (BLV). Under narcotics law, the total THC value remains decisive: under 1% (THC + THCA × 0.877) it is not a narcotic. Anyone working in their own kitchen for personal use operates outside of food law — if the result is sold or given away, it is immediately considered placing on the market.

Decarboxylation as an essential preparation step

Thermal activation, also known as decarboxylation, is the crucial first step before the actual extraction into cooking oil. In the raw cannabis plant, the active ingredients exist predominantly in their acid forms, such as THCA and CBDA. These acids are non-psychoactive and exhibit different pharmacological properties than their activated counterparts. Only through the targeted application of heat is a carbon dioxide molecule split off, creating the desired cannabinoids THC and CBD. Without this process, home-made oil remains largely ineffective, as binding to the body's own receptors does not occur.

For even activation, coarsely grind the dried flowers and spread them on a baking tray. Since conventional ovens often display inaccurate temperatures, using an external oven thermometer is recommended for precise monitoring. Temperatures that are too high destroy the sensitive cannabinoids and volatile terpenes, while temperatures that are too low leave the process incomplete. After thermal treatment in the oven, the plant material is ready to be dissolved in the chosen oil, with the fat serving as the carrier medium for the activated molecules.

• Acid forms (THCA and CBDA) are converted into the active forms (THC and CBD) by heat.
• Coarse grinding of the plant material ensures even heat distribution in the oven.
• An external oven thermometer prevents overheating and the loss of valuable terpenes.
• Thermal activation must strictly take place before mixing with the cooking oil.

Practical guide to filtration and purification

Following the actual extraction process, in which the activated plant material infuses in the warm oil over several hours, the mechanical separation takes place. This step requires care, as remaining plant residues in the final product impair the taste and drastically increase susceptibility to mould formation. A fine straining cloth, a nut milk bag or an unscented coffee filter is suitable for filtration. The warm oil-herb mixture is slowly poured through the strainer, whereby gravity should do most of the work to retain turbid substances in the filter.

A common practical mistake is squeezing the filter material too hard at the end of the process. Although this seemingly increases the yield, it forces more bitter substances, chlorophyll and unwanted plant waxes into the finished oil. This leads to a harsh taste and reduces the shelf life of the product. After filtering, the clear, greenish-brown oil should be filled directly into sterile, dark glass containers. Working cleanly prevents contamination with germs, which is essential for subsequent storage.

• Use of straining cloths or nut milk bags for residue-free filtration.
• Avoiding hard squeezing to minimise the introduction of bitter chlorophyll.
• Bottling in sterile amber glass bottles protects the oil from light-induced degradation.
• Residues in the oil promote bacterial decomposition and shorten the shelf life.

Dosage risks and emergency assistance in case of overdose

The oral ingestion of cannabinoids via homemade oil carries a significantly increased risk of accidental overdose compared to inhalation. Since the onset of action is delayed by half an hour to two hours, inexperienced consumers tend to take an additional dose prematurely. Furthermore, without laboratory analysis, the active ingredient content in homemade oil can hardly be determined precisely. The effects also last significantly longer and can be perceived as much more intense, which can lead to severe discomfort in unprepared individuals.

If an overdose occurs, manifesting as a rapid heartbeat, dizziness, sweating, or anxiety, calm and deliberate action is required. Those affected should be taken to a quiet environment and provided with sufficient water. In Switzerland, in the event of severe symptoms of poisoning or persistent uncertainty, the emergency number of Tox Info Suisse is available 24/7 on 145 for expert, free advice. Clear labeling of the oil bottles in the household also prevents bystanders or pets from accidentally consuming the oil.

• Delayed onset of action of up to two hours tempts consumers into dangerous redosing.
• A lack of laboratory analyses makes it difficult to determine the exact concentration of active ingredients in a home laboratory.
• Longer and more intense duration of action with oral ingestion compared to inhalation.
• Tox Info Suisse (emergency number 145) offers rapid and free assistance in the event of an overdose.

Swiss road traffic and legal consequences

The consumption of homemade cannabis oil has far-reaching consequences for the ability to drive in Swiss road traffic. Unlike other European countries, Switzerland enforces a strict zero-tolerance policy regarding THC at the wheel. The statutory detection limit is 1.5 micrograms of THC per litre of blood. Since THC and its metabolites are broken down very slowly after oral ingestion via edible oils, driving impairment can still be detected many hours or even days after actual consumption, even if no subjective effects are felt anymore.

Anyone caught at the wheel with a level above the limit is legally deemed unfit to drive, resulting in the immediate revocation of their driver's licence. In addition to heavy fines, there is usually a risk of a lengthy procedure to review driving aptitude by the cantonal road traffic offices. Even when using supposedly legal CBD oil with a total THC content of less than 1%, there is a risk of exceeding the limit in the blood if the product is consumed regularly or in larger quantities.

• Strict zero-tolerance policy in Swiss road traffic with a limit of 1.5 µg/L of blood.
• Slow degradation of orally ingested cannabinoids prolongs the risk of driver's licence revocation.
• Even CBD oils with less than 1% THC can exceed the limit with regular consumption.
• Cantonal road traffic offices often order lengthy driving aptitude assessments in the event of violations.

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