Joining the Gold Rush: Cold Extraction with Merlin400

Skilled merlin400 users are coming up with golden, honey-like extracts of very high purity, made at home. This has inspired me to take up the challenge: Make a top-quality, high-purity golden extract using all the available tips and tricks!

Just under 2 grams of pure golden extract, fresh from Merlin400

People have made extracts, concentrates, and oils for centuries – and until recently, the typical extract has been a sticky black substance with a feel and viscosity like tar. These extracts, typically known as FECO (full extract cannabis oil), are made by extracting everything that will dissolve in alcohol (e.g. isopropyl alcohol/IPA, the solvent used in Merlin400) from the herbs.

FECO has its advantages and drawbacks. One advantage is that you can make the extracts by hand using relatively simple tools. One drawback is that the purity – the balance between wanted and unwanted compounds – is relatively low.

In recent years, with the introduction of extracts made on an industrial scale and equipment, the purity of the extracts has come up, and the look and feel have changed from black and tar-like to golden semi-transparent honey-like substances.

These pure, golden extracts have been almost impossible to achieve by hand, mostly because you need to control the extraction more precisely than what is possible without precision tools.

Merlin400 changes that game. With it, you control the extraction process as precisely and repeatably as with industrial extraction equipment. But Merlin400 will not do it alone – it’s a tool, and like all tools, you need to use it the right way to get the results you want. And several additional steps are needed to get the quality extracts we are hunting…

This is what I have learned from my own experiments and from listening to other Merlin400-users:

  • While you can make great FECO extracts from low-quality herbs (eg. Industrial hemp, trim, etc.), you need to start off with high-quality buds with little or no green, leafy parts, if you want a really high-quality extract.
  • Granulating the herbs for extraction using a grinder or a blender with sharp blades will tear the plant cells open and raise the amount of unwanted chlorophylls etc., available for extraction. I found that using a hand blender with dough hooks for granulating the herbs works like a charm.
  • The herbs must be dry. The wanted compounds dissolve in alcohol/IPA, while the unwanted ones mostly dissolve in water. Even a small amount of water in semi-dry herbs will raise the amount of unwanted compounds in the final extract.
  • Freezing the herbs and the IPA gives a higher purity of the extract. The unwanted compounds typically freeze at a higher temperature relative to the wanted, more volatile compounds. Extracting frozen herbs using cold IPA drastically reduces the yield, so you will need to run a second extraction on the herbs to get all the available cannabinoids out from the herbs. With Merlin400, it is possible to perform the second extraction while the herbs and IPA are still frozen, keeping the purity of the second extract almost as high as the first.
  • Finally, it seems that you can purify your extract in a process named warm/hot curing. I have not yet tried this final step, so this might be where you join in? I will test this process soon, but if you have been there already and you want to share your experience and knowledge, please do in the comments below. When we all share our knowledge, we all get wiser!

My results so far: 4 different extracts from the same high-quality herbs.
The herbs were granulated using a hand mixer with dough hooks, dried for 30 minutes on top of an oven, frozen for 24 hours, and extracted using Merlin400.

Top left: 1st run, 28g frozen herbs+freezer-cold IPA. Yield approx. 1.9g. (6,8%)
An absolutely delicious yield!

Top right: 2nd run on the same 28g herbs while still frozen + the IPA leftovers that dripped from the herbs after 1st+2nd run.
Yield approx. 1,2g. (4,3%) but even with less extract in the glass, it still appears slightly darker than the 1st run.

Bottom left: 3rd run, reference run of approx. 14g of the same herbs, but at room temperature.
Yield approx. 1,7g (12%) – a little less than the 1st run in absolute numbers, but darker at the rim of the glass. Freezing the herbs seems to give a slightly more transparent extract, but not as much as expected.
The yield in % from the 3rd run at room temperature is 12% compared to 11,1% from the cold 1st and 2nd runs combined – meaning that frozen herbs only give off 50-60% of the available extract in the first run, compared to extraction at room temperature.

Bottom right: the 28g herbs from 1st and 2nd run, extracted again at room temperature 24 hours later. Yield approx. 0,5g (1,8%) – judging by the look, smell, and feel, this is all the stuff you don’t really want in your golden, high-purity extract.

Now I want to continue to warm-curing these extracts. Any tips and tricks regarding temperatures, times, and conditions will be highly cherished, used, evaluated, and shared!