Cold water extraction
Cold water extraction (CWE) is useful to filter cutting agent that doesn't dissolve in water. For example, caffeine is a common cutting agent with poor water solubility.
- If you need to calculate the loss of drying: Dry the substance, see drying and humidity standardization of substances. Otherwise, just use a coarse strainer, and then a fine strainer.
Cold water extraction
For a single dose
For a whole batch
The potency of the dried weight before and after the extraction can differ several folds (see the example section below). So it's extra important to dosage properly after the extraction! Avoid eye balling, since a lot of street drugs can be overwhelmingly potent after the majority of the cutting agents have been removed. Avoid extraction altogether if you don't know how to dose it.
For improved extraction, it's recommended to do an acetone wash (not covered in this guide) before you do the CWE, but it is not required.
- Add the fine powder to a glass jar, and add 10 times more boiling water than the quantity of the substance, and shake well for 10 seconds. This should precipitate the soluble substances in the water.
- Let the water cool down to room temperature.
- A fine nylon mesh (used for tea) can be used to filter out most of the impurities with water. However, to sediment all non-water dissolving cutting agents either:
- Letting the glass jar stand for 2–3 days. For substances that will oxidize, just let it stand for just an hour to get rid of most of the sediment, then soak the semi-clear solution with a syringe and use a syringe filter to get rid of the final sediment.
- Pouring the solution in a glass baking dish and carefully tint the solution to a corner where you soak it up with a large glass syringe.
- Put the clear phase in a glass baking dish and let evaporate. Use several glass baking dishes to get more surface for quicker evaporation. Heat, such as a heating mat, often evaporates a portion of the substance.
- The substance will stick to glass surface when dissolved with water, so use a baking scraper, and finish scraping the residues with a razor blade.
- Weight the substance again, and compare it with the weight in step 1.
- Repeat the steps with the sediment to precipitate the 10% water-soluble substances.
- Throw away the impurities.
- A main advantage of extraction is to calculate how many percentages that have been cut. However, it is not uncommon that the purity will be twice as strong. To avoid accidents from impulsive eye balling, you can cut it will glucose powder which is also water-soluble.
Example purity after extraction
A moist lump that weighed a one gram.
- 40% loss in drying.
- 15% loss in acetone wash.
- 20% cold water extraction.
- Impurities before extraction: 40%+15%+20% = 75%
- Potency after extraction: 100/(100-(40+15+20)) = 4 times more potent
Note that this doesn't include water-soluble impurities.