Extraction and Pressing – Methods Guide

Extraction is the process of obtaining concentrated active compounds from plant material – essential oils, resins, terpenes, flavonoids, and other valuable substances. From lavender oil through herbal tinctures to medicinal plant concentrates, extraction techniques have a thousand-year tradition, yet modern equipment takes their efficiency to an entirely new level.

In this guide, we will discuss the main extraction methods available to home processors, compare their advantages and disadvantages, and focus on safety and legal aspects in the Czech Republic.

1. Overview of extraction methods

Extraction methods are divided into two basic categories:

Solventless (mechanical) methods

They do not use any solvents – working purely with heat, pressure, or mechanical separation. The resulting product is pure, without solvent residues, and therefore popular with processors who emphasize natural processes.

• Rosin press (heat + pressure)
• Dry sift (mechanical sieving)
• Ice water hash (ice water + stirring)

Solvent-based (solvent) methods

They use a solvent to extract active compounds from plant material. The solvent is subsequently evaporated, leaving behind a concentrate. These methods generally provide higher yields but require stricter adherence to safety rules.

• DME (dimethyl ether) – a more modern and safer alternative to butane
• Ethanol – traditional method for tinctures and macerates
• CO2 (supercritical) – industrial method with the highest purity output

2. Rosin press – heat and pressure

The rosin press is currently the most widespread solventless method for home processors. The principle is straightforward: plant material is placed between heated plates and under controlled pressure, resin rich in active compounds is pressed out of it. The advantages are speed, simplicity, and complete absence of chemicals.

How it works

1. Plant material (dried flowers, dry sift, or ice water hash) is placed in a nylon mesh filter bag.
2. The bag is placed between heated plates presses.
3. Pressure is applied (typically 500–2,000 kg across the plate area) at a precisely set temperature.
4. Resin flows from the material and is collected on parchment paper placed below the plates.

Key parameters

Lower temperatures preserve the aromatic profile and are especially suitable when you prefer quality over yield. Higher temperatures are useful for lower-quality input material or where volume is the priority.

Input materials and yield

The best results combining quality and yield are provided by pressing ice water hash – the input material is pre-cleaned of chlorophyll and plant matter, so the output is cleaner and aromatically richer.

Filtration – bag mesh size

Filter bags (micron bags) significantly affect the purity and yield of the extract. Smaller meshes capture more impurities but allow less resin to pass through:

• 25 microns – highest purity, lowest yield; suitable for premium hash.
• 37 microns – good compromise for pressing hash.
• 90 microns – standard choice for dried flowers.
• 120–160 microns – higher yield at the cost of lower product purity.

Equipment

Presses are available in various designs – from compact manual models to hydraulic machines with digital temperature control and precise gauges. Among press accessories are filter bags of various sizes, parchment paper, collection scrapers, and silicone containers for storing the resulting product.

Tip: Even distribution of heat and pressure across the entire plate surface is key to consistent results. Cheaper presses suffer from uneven heating – material burns in one place and remains unpressed in another. An investment in quality equipment pays off in the long run.

3. DME (dimethyl ether) extraction

DME extraction uses liquefied dimethyl ether as a solvent. It is a more modern alternative to butane extraction (BHO), gaining popularity due to higher yields, faster evaporation, and a more favorable safety profile.

How it works

1. Dry plant material is placed in an extractor – typically a stainless steel tube with tight joints.
2. Liquefied DME is forced through the material and dissolves the active compounds.
3. The solution is collected in an evaporation dish.
4. DME evaporates quickly at room temperature (boiling point -24.8 °C) leaving behind a pure concentrate.

Advantages of DME over butane

The wider solvent spectrum of DME is both an advantage and a disadvantage: the extract contains more terpenes and flavonoids, but also more chlorophyll, which accounts for darker color. For many processors, this is an acceptable trade-off for significantly higher yield.

DEXSO and Ehle X-trakt

DEXSO DME extraction represents the reference system for home DME extraction. Components are designed specifically for safe use with dimethyl ether, with precisely dimensioned valves and connecting elements that minimize the risk of gas leaks.

Ehle X-trakt is another proven variant of extraction equipment emphasizing precise processing. You can find both systems in the extractors category.

Safety rules for DME

DME is a flammable gas – without exception follow these rules:

1. Work only outdoors or in a space with intensive forced ventilation. Never in a closed room.
2. Eliminate all sources of flame, sparks, and electrical equipment in the immediate vicinity of the work area.
3. Do not smoke and do not use open flame or candles during the entire process.
4. Use antistatic gloves – static discharge can ignite DME vapors even without visible sparking.
5. Store containers with DME in cool conditions, away from direct sunlight and heat sources.
6. Never heat a container with DME – pressure buildup can cause explosion.
7. Always follow the extractor manufacturer's instructions and do not improvise with incompatible components.

4. Dry sift (dry sieving)

Dry sift is probably the oldest and most straightforward extraction method. Dried plant material is mechanically sieved through screens with various mesh sizes, separating trichomes (resin glands) from the rest of the plant. It requires no chemicals or complex equipment.

Procedure

1. Place well-dried and preferably pre-frozen material (freezing increases trichome brittleness) on the top screen with the largest mesh.
2. Gently shake or wipe the material across the screen with regular movements.
3. Trichomes fall through the screen and collect on a pad or finer screen beneath it.
4. For higher purity, repeat sieving through a multi-stage system from coarser to finer mesh.

Purity grades

The terms "full melt" and "half melt" describe the material's behavior when heated – full melt melts completely without leaving residue, half melt leaves small residue.

Equipment

For dry sift you need screens with precisely defined mesh size and a sufficiently rigid frame that prevents screen sagging under pressure. In the extractor accessories category you will find screens, collection cards, plastic scrapers, and silicone pads for easy collection of sieved material.

5. Ice water hash (ice water extraction)

The method uses ice water and mechanical stirring to separate trichomes from plant material. Low temperature causes trichome brittleness – they separate from plant fibers more easily and fall through screens into a collection container. The result is so-called bubble hash, which is among the highest-quality solventless concentrates.

Procedure

1. Place plant material and large amounts of ice in a bucket with washers (bubble bags) stacked by mesh size from finest on the bottom to coarsest on top.
2. Pour ice water and stir intensively for 15–20 minutes – by hand or with an electric mixer.
3. Trichomes separate, fall through mesh bags, and collect in bags of corresponding size.
4. Remove bags sequentially from coarsest to finest – each grade contains different quality material.
5. Dry collected hash for 24–48 hours on a drying screen in a well-ventilated space.

Quality by fraction

The highest-quality material typically collects in bags with 73–120 micron mesh – this fraction contains mostly intact trichome heads with the highest concentration of active compounds. Coarser fractions (160+ microns) contain more plant material and are better suited for cooking. The finest fractions (25–45 microns) capture small impurities and lower-quality residue.

Tips for maximum quality

• Use the coldest water possible – add large amounts of ice, even during stirring.
• Do not stir too aggressively – excessive mechanical force breaks trichomes and reduces result purity.
• Dry slowly and thoroughly – underdried hash is prone to mold and deterioration.
• Freezing input material before extraction increases yield and purity because trichomes separate more easily.

Washers and humidity control bags are basic equipment for this method.

6. Methods comparison

Which method to choose?

• For beginners: Dry sift – minimal initial investment, no safety risks, immediately understandable procedure.
• For maximum quality: Ice water hash combined with rosin press – pre-sieved hash pressed at low temperatures yields the cleanest and most aromatically rich result.
• For maximum yield: DME extraction – you get the most concentrate from a given amount of input material.
• For simplicity and speed: Rosin press – place material, press, and in two minutes you have a finished product without further waiting for evaporation.

7. Legal aspects in the Czech Republic

Extraction equipment itself is not prohibited in the Czech Republic – presses, extractors, and all accessories are legally sellable goods. These devices have wide legitimate application in processing herbs, spices, aromatic plants, beeswax, propolis, and food ingredients.

Important note: Processing plant material containing controlled substances is subject to drug laws (Act No. 167/1998 Coll.). Always inquire about the current legal status and process only legal plant material.

Legitimate uses of extraction techniques include:

• Production of essential oils from herbs and aromatic plants.
• Processing lavender, rosemary, mint, and other garden crops.
• Preparation of herbal tinctures and macerates for home and cosmetic use.
• Extraction of beeswax and propolis.
• Obtaining natural plant dyes.
• Food applications – processing spices, hop extracts, and aromatic additives.

8. Equipment maintenance and care

Regular and proper maintenance extends equipment life, prevents contamination of extracts with residue from previous batches, and ensures consistent results.

Presses

• After each use, wipe the heated plates with isopropyl alcohol (IPA 99%).
• Regularly check pressure evenness – uneven loading causes poor extraction and premature plate wear.
• On hydraulic presses, regularly check the level and condition of hydraulic fluid and seal tightness.

Extractors

• After each use, thoroughly rinse all parts.
• Check the tightness of joints, valves, and seals – even minor gas leaks present a safety hazard.
• Store in a dry, clean place away from heat sources.

Filter bags and screens

• Immediately after use, rinse with clean isopropyl alcohol, then rinse with water.
• Air dry at room temperature – never in a dryer, which can deform or damage the mesh.
• Before each use, check mesh integrity – damaged mesh lets impurities through and reduces extract quality.

Frequently asked questions (FAQ)

Is the rosin press safe for home use?

Yes, the rosin press is the chemically safest available extraction method. It uses no solvents, flammable gases, or chemical additives. The only real threat is burning on the heated plates – handle the device with the same caution as an iron or waffle press.

What is the difference between DME and butane extraction?

DME (dimethyl ether) has a significantly lower boiling point (-24.8 °C compared to -1 °C for butane), which causes it to evaporate faster and leave fewer residues. It is less explosive, has food-grade approval, and dissolves a wider spectrum of compounds – resulting in higher yield but also darker color due to greater chlorophyll content.

Can I use a press to produce essential oils?

A rosin press is primarily designed for resin extraction, not essential oils, which are produced by steam distillation. However, the press provides excellent results when processing aromatic herbs, dried flowers, and resinous material – the output is an aromatic plant extract, similar in character to oleoresin.

How much material do I need for meaningful extraction?

For rosin press: the recommended minimum is 3–5 g per pressing, with smaller amounts difficult to evenly fill the bag. For ice water hash: ideally 50–100 g for efficient processing and meaningful product amount. For dry sift: the method works with 10 g, but larger input amounts significantly improve sieving efficiency. For DME extraction, the ideal amount depends on the capacity of the specific extractor.

How to store finished extracts?

Store finished concentrates in an opaque, airtight container – ideally glass or silicone. Contact with metals can affect taste and composition in some extracts. Store in darkness and cool conditions (refrigerator is ideal), bringing the container to room temperature before opening to prevent condensation on the extract. Humidity control bags help maintain optimal conditions even during longer storage.

Sources

• Solventless Extraction Guide – Low Temp Plates
• How to Press Different Types of Rosin: Complete 2025 Guide – Hydrobuilder
• Cannabis Extraction Equipment – Dexso
• DME Dimethyl Ether Solvent – Dexso
• Solventless Extraction Techniques – Root Sciences
• Bubble Hash vs Rosin – Low Temp Plates