The Complete Step‑by‑Step Process of Making Cold‑Pressed Oil
In today’s kitchen landscape, “cold‑pressed” oil has become an important label—highlighting extraction by mechanical means rather than heavy refining. Yet what does the production journey really look like? Below is a detailed walk‑through of how cold‑pressed oil moves from raw seeds or nuts into your bottle, capturing the craft, equipment and decisions behind it.
What “Cold‑Pressed” Means
“Cold‑pressed” refers to an oil extraction process in which seeds or nuts are pressed mechanically at a relatively low temperature (rather than being heated or chemically treated). The emphasis is on avoiding high external heat or solvent‐based treatments, so the oil retains more of the original flavour, aroma and texture of the seed or nut.
In practice, this method typically uses either traditional wooden or stone presses (for example the Indian “ghani” or “chekku”) or modern screw/expeller machines designed to operate at controlled speeds and kept under defined temperature limits. (SutraKart.com)
Seeds and Nuts Commonly Used
Many types of seeds or nuts can go into cold‐pressed oil: groundnuts (peanuts), sesame seeds, coconut kernels, sunflower seeds, mustard seeds among others. The choice of raw material influences the final characteristics of the oil — its aroma, colour, texture and suitability for a particular cuisine or dish.
Step‑by‑Step: Cold‑Pressed Oil Production
Step 1: Raw Seed Selection
The initial step is all about picking high‑quality raw materials: mature seeds or kernels that are free of visible damage, mold, excess moisture or foreign matter. Many producers emphasise sourcing seeds that have been grown under better conditions, though practices vary. (SutraKart.com) Good input material sets the stage for a good extraction.
Step 2: Cleaning & Sorting
Once raw seeds are selected, they undergo cleaning: removal of stones, sticks, husk fragments, dust, debris. Sorting can also remove broken seeds or inferior quality bits. This step is important because unwanted material can interfere with extraction, affect yield or introduce off‑flavours. (SutraKart.com)
Step 3: Drying the Seeds
Moisture in seeds affects how smoothly the pressing will go and how well the oil flows out. Drying (either through sun‑drying or low‐temperature drying) helps reduce seed moisture to acceptable levels, preventing problems like foaming, spoilage or extraction inefficiencies. (Harappa)
Step 4: Optional Seed Pre‑Conditioning
In some cases, seeds may undergo very light conditioning (for example mild roasting, gentle heating or partial crushing) to aid pressing. However, in a true cold‑pressed process, the external temperature should remain low and avoid high heat or chemical aid. Some brands emphasise that no added heat is incorporated beyond the mechanical friction limit. (SWA – Soulfully Good)
Step 5: Mechanical Pressing (Extraction)
This is the core activity: pressing the prepared seeds to extract oil. Two main types of equipment are used:
- Traditional wooden/stone press (chekku/ghani): The seeds are slowly crushed by a rotating wooden or stone mechanism. Historically bullocks powered it; today slow motors drive it. The slow speed ensures minimal heat build‑up. (SutraKart.com)
- Modern screw or expeller press: A steel machine that compresses the seeds under mechanical pressure. The temperature inside the machine is monitored and kept within a defined low range (often under ~40‑50 °C) to qualify as “cold‑pressed.” (Olixir Oils)
As the press works, the oil separates out and flows from the machine. What remains is a solid “press‑cake” or “meal” of seed residue which is removed or repurposed. (Wikipedia) The slower the process and the better the machine is maintained, the cleaner the extraction will be.
Step 6: Sedimentation & Filtration
After extraction, the oil typically contains suspended seed particles, fine seed fragments, potentially small amounts of moisture or solids. The oil is allowed to settle in tanks or containers so that heavier solids sink. After settling, a basic filtration is done (often through cloth, mesh or natural filter) to remove remaining debris. This step gives the oil clarity and stability. (SutraKart.com) No bleaching or heavy refining is used in a pure cold‑pressed process.
Step 7: Packaging & Bottling
Once the oil is filtered and clarified, it is transferred into bottles or containers. Packaging choices matter: many producers use dark glass, tinted bottles or opaque containers to protect the oil from light. Caps or seals that restrict air ingress help maintain freshness. Labels might include seed type, batch number, pressing date and processing method. This step prepares the product for retail. (SutraKart.com)
Step 8: Storage & Distribution
Finally, the filled oil containers are stored in cool, dry, dark conditions until shipping. Because the oil has not undergone intensive refining, it may have a different shelf characteristic than heavily processed oils. Hence environment (light, heat, air) plays a role. Many producers recommend shorter turnover and correct storage to maintain the characteristic aroma and texture. (SutraKart.com)
Why Each Step Matters
- Selection sets the baseline: inferior seeds lead to inferior output.
- Cleaning & drying reduce contamination, improve yield, avoid extraction issues.
- Pressing — by avoiding high external heat or solvents — preserves the original seed profile (colour, aroma, texture) and provides an extraction method that is more artisanal.
- Sedimentation/filtration ensure clarity and removal of undesired solids, which improves usability and storage behaviour.
- Packaging and storage allow the oil’s qualities to be maintained until consumer use.
The entire chain, from raw seed to bottle, involves mechanical extraction, minimal external processing and care at each stage. That’s what sets “cold‑pressed” apart from conventional refined oils.
Traditional vs Modern Cold‑Pressing
Traditional (Wooden Ghani / Chekku)
In many regions, especially in smaller or artisanal setups, the wooden/stone press is still used. The seeds go into a wooden mortar with a wooden pestle or press rod that rotates slowly. The low rotation rate means less friction‑heat. Straps or oxen may have powered earlier systems; today motors are common. This method tends to produce lower quantities per hour, but many value the flavour and traditional characteristics. (SutraKart.com)
Modern Cold‑Press / Screw‑Expeller
To meet higher demand, steel screw‑press machines are used. These are designed for continuous feed of seeds, have higher throughput, and often include temperature sensors and cooling arrangements to keep extraction under the threshold for “cold” classification. They offer higher yield and faster processing while maintaining the low‑temperature condition. (Wikipedia)
Both methods aim to extract oil mechanically and at low temperatures; the primary difference lies in scale, yield and equipment.
Practical Considerations for Users & Buyers
When selecting a cold‑pressed oil for your kitchen, these practical aspects help:
- Processing method disclosure: Check whether it states “cold‑pressed,” “unrefined,” “virgin,” or “kacchi ghani.” These suggest minimal processing.
- Packaging clarity: Dark bottles or tinted glass are preferred. Clear plastic may expose the oil to light which can affect performance.
- Batch & date information: Freshness matters; shorter shelf turn‑over often means better quality.
- Storage advice: Once opened, keep the container away from direct sunlight, heat sources (like stove surfaces) and use within a reasonable time.
- Sedimentation or light cloudiness: In pure cold‑pressed oils you may see natural sediment or slight change when storage temperature varies — this is normal and reflects minimal processing rather than defect.
- Use type: Because flavour and aroma remain characteristic of the seed, match the oil to your cooking style (for instance a nutty sesame press for finishing dishes, a mild groundnut press for everyday sautéing).
- Yield & price: Cold‑pressed methods typically have lower yields and may cost more than refined oils — this is due to slower extraction, lower throughput, and minimal refining.
Summary
The process of making cold‑pressed oil — from seed or kernel through cleaning, drying, low‑temperature mechanical pressing, settling, filtration and final packaging — emphasises preserving the natural identity of the raw material. Whether produced in a traditional wooden check‑press or a modern screw‑press, the key features are mechanical extraction, avoidance of high heat or chemical solvents, and minimal further processing.
For those seeking oils where the seed’s flavour and aroma are more evident, understanding how the oil is made helps in selecting accordingly. Knowing the steps — selection → cleaning → pressing → filtration → bottling — gives consumers an insight into what happens behind the label, and what to look for.