3 parameters hash oil blowers can control that improve live resin quality

Effective purging is dependent on three things – temperature, surface area, and pressure.

The right combination of these parameters will remove butane from the extract and leave you with a translucent slab of high quality oil. The wrong combination will leave you with a sticky mess that’s destined for a burn pile in your backyard.

To preserve terpenes, the lower the temperature, the better.

Butane and terpenes are some of the first molecules to evaporate while purging. An important point on purging temperatures: vacuum oven temperature may not translate to oil temperature. This is a point that is easily forgotten, and can be the difference between a product that shatters versus a pull-and-snap consistency. Check the temperatures of your oil with an infra-red thermometer.

There are several ways of removing the butane while retaining terpenes.

Keep in mind the boiling point of butane – it’s -0.5C/32.5F. If you purge long enough at room temperature at full vacuum, you will boil off all the butane – that process can take up to 5 days. Alternatively, you can increase temperature on your vacuum oven until the oil reads a steady 46C/115F, then pull a full vacuum.

Spread the extract as thin as possible so that the butane is exposed to the surface and boils off with minimal effort.

Surface area is the next big point in extractions. You need to spread the extract as thin as possible so that the butane is exposed to the surface and boils off with minimal effort. If you have the extract pooled up in a small container, it will eventually fully purge, but at geological time scales. This is best done with a two step process of pouring out the bulk of the extract onto one silicon mat and scraping out the residual extract with a spatula followed by spreading it onto a second silicon mat. This process minimizes auto buttering of the poured batch and requires the least amount of handling.

Cycle your vacuum on periodically.

Vacuum cycling is the next issue: cycle your vacuum on and off every 60 minutes, and keep it on for at least 10 minutes. Whenever there is a vacuum on the chamber, the extract is off-gassing butane, terpenes, and any other volatile molecules. If you pull vacuum on the chamber, but then shut off the pump, the chamber will fill with butane. Without getting too technical about the partial pressures of gasses, the butane gas in the chamber affects the rate of evaporation from the extract; it’s like having a room filled with balloons – if you’ve filled up the room, you can’t inflate more balloons until you get rid of the ones occupying the space.

Conclusion.

By controlling the purge temperature at the oil, increasing the surface area, and cycling your vacuum, you’ll be on your way to dialing in your strain’s preferred conditions for making exquisite extracts. Unfortunately not all strains behave the same, and you’ll have to adjust temperatures and the timing of your vacuum pulls accordingly.

What every hash oil extraction artist needs to know about temperature

Four temperatures parameters.

Terpenes are a valuable product captured the extraction process. Not controlling temperatures through the extraction will cause you to lose terpenes. There are four temperature parameters that need to be controlled in live resin extractions – fresh plant materials, butane, column, and purging temperatures.

Freezing live plant materials under inert conditions.

Live resin requires low temperatures to extract cannabinoids and terpenes and leave behind water and plant waxes. Since dry ice and ethanol are required for almost every step, it makes sense to use it for flash freezing the plant material. This is done by filling vacuum bags with fresh plant material in a way that maximizes surface area. Once filled with plant material, the bags are filled with dried CO2 gas to purge out the humidity from the room. The bags are vacuum sealed, dipped into a dry ice bath until fully frozen, and are then made ready to fill into a prechilled column.

There are many ways to freeze plant material. Choose the one that works best for you. 

Cooling your butane with a condensing coil.

Control your butane temperature before it comes in contact with the plant material. If you don’t, your freshly frozen plant materials will thaw from the warm butane, and start to release plant lipids. Pass your butane through a condensing coil that is submerged in a dry ice/ethanol bath – on average, the dry ice bath will cool the butane down anywhere from -20C to -50C. The cooling capacity, or rate of cooling, is dependent on the size of the bath and the amount of dry ice added to it. Once cooled down, the liquid butane passes into your packed column and the extraction begins.

Temperature control at the column is key to long soak times.

A commonly missed point is that the column must be frozen in the freezer prior to extraction. Do this, and you’re one step ahead of the game.

A problem with long soak times is that the frozen plant material can be warmed up if the column temperature is not controlled. This causes the water that’s locked up in the solid phase (i.e. ice) from plant cells to release water, water-soluble phytochemicals, and plant lipids/waxes. 

After the cooling coil, butane temperature needs to be controlled at the column. Keeping the column at a temperature less than -20C (optimally -30C to -40C) ensures water and waxes do not contaminate the extract. The column temperature can be controlled by a dry ice/ethanol bath; it can be connected to a cryogenic pump or just be an open sleeve/cylinder filled dry ice and ethanol. If dry ice isn’t available, an ice bath will improve your extractions.

Transferring to thin film and purging.

You’ve finally got your live resin extract in the collection chamber of your extractor. Live resin extracts are low viscosity – the additional terpenes decrease the internal friction of the liquid. Pour the extract onto silicon mats, then scrape out the collection chamber with a silicon spatula and transfer it onto a second mat. You’re now ready to purge.

Live resin purging – temperature and time.

Two important components in any chemical reaction are temperature and time. Higher temperatures cause loss of terpenes, but decrease the purging times to boil off all the butane. Keep your purging conditions below room temperature and not much below 5C. This preserves terpenes, but is still above the boiling point of butane. To make up for the lower temperature, increase the amount of time spent purging to 5 days. This is the simplest process to preserve your terpenes, and make your live resin runs worth while.

General purging tips.

A favored way of purging is to heat the extract up to it’s purging temperature for 30 minutes without pulling a vacuum. Once the oil is up to your desired purging temperature, you can pull a full vacuum. Purging times vary from strain to strain, but you can follow the bubbles to see when your extract is purged. The purging has nearly completed when the major bubbles of butane stop forming – those bubbles are typically large and burst when they reach their maximum size. You’re looking for the point when the bubbling slows down and only small bubbles form. At this point, you can dial in your process with residual solvent testing at your local laboratory to confirm when your extract is fully purged.

Conclusion.

Properly controlling temperatures of fresh plant materials, butane, column, and purging will improve your process. There are multiple benefits at each step, that when combined create perfect conditions for preserving the essence of the fresh plant – the terpenes. Not all starting materials are worthy of making live resin. When you do have good starting materials, you will be rewarded with knockout flavor and taste that would have otherwise been lost to the atmosphere. Follow these steps and enjoy the experience.

 

As always, if you have any questions please post them in the comments section. Your questions and time are valuable and we will make every attempt to help you through your process.