What's Actually In Hash Wash Foam?

Wash foam has been a topic of discussion in the solventless community for years. There are countless Reddit threads and LinkedIn posts where people have made assumptions and argued over what makes a wash foamy, why some washes foam more than others, and whether heavy foam is a bad sign. To properly answer any of those questions, you have to start at square one: what is actually in the foam?

Some say it's terpenes. Some say cannabinoids. Others say chlorophyll, saponin. Some folks say foam is a bad sign while others say it is no big deal. The problem is that none of those takes were ever backed by actual data. 

We decided to change that with our most recent experiment; we were able to get a real look at what makes up the foam generated when washing fresh-frozen cannabis. 

How the Test Was Performed

We collected a sample of wash foam from a wash of Razzbox and sent it to Tryptomics for untargeted metabolomics testing. This means they looked at everything in it, not just cannabinoids and terpenes. The result was a full chemical profile of 32 identified compounds.

• Strain: Razz Box Pie
• FF Weight: 13,199.54g
• Room Temp: 56 degress
• Water temp: 33-34 degrees
• Foam Sample Weight: 102.04g
• **Sample was instantly frozen and kept frozen up until testing.

Before we break down what those compounds are and what that means for your wash, it's important to note this is qualitative testing, not quantitative. That means we can confirm these compounds exist in the foam, but not their exact percentages. Some compounds are naturally identified more clearly in the mass spectrometer, while others fragment and show smaller signals. In the words of Caleb K., Co-Founder, CSO, and Analytical Chemist at Tryptomics:

"I would caution the interpretation of the signal percentage as this can be deceiving. Some compounds ionize really well in the mass spectrometer and correspond to high peak heights, while other compounds fragment (break into molecular segments) not as well and thus show smaller signals. Fragmentation does not always equal concentration; hence, why we are specific when describing this test as qualitative instead of quantitative."

What Compounds Were Found in the Foam

The 32 detected compounds fell into several broad categories. You can download the full test results here. Here's what each one tells us.

Plant Sugars and Carbohydrates

The single largest signal in the entire test was mome inositol, a plant-derived sugar alcohol involved in cellular metabolism. This makes a lot of sense. Inositol is found inside plant cells, so its presence directly indicates that mechanical agitation during the wash is breaking down plant material and releasing intracellular compounds into the water. It is worth noting though that inositol itself is not what is making your wash foamy, as it simply lacks the surface-active properties needed to stabilize bubbles. It is more of an indicator that cell rupture is happening than a direct cause of the foam.

Proteins, Lipids, Terpenes and Cannabinoids

Beyond inositol, the test detected glycoproteins and proteinaceous plant components, three terpenes (linalool, β-fenchol, and α-terpineol), cannabinoids (THC, CBC, and CBN), and long-chain fatty acids including palmitic acid, stearic acid, and hexadecanoic acid. These all tell the same story: agitation is breaking down plant cellular material and gland structures and releasing their contents into the water.

So did these compounds cause the foam? Not exactly. The proteins and lipids are surface-active and do contribute to foam stabilization, but they are not the main drivers. 

Other Compounds

The remaining compounds detected included benzoic acid and other aromatic plant secondary metabolites and several pyrazines. None of these are significant foam contributors, and like the silicone compounds below they exist only in the water phase and are not making it into your finished hash. 

Trace phthalates are commonly encountered in analytical testing environments and are consistent with incidental contact from processing and storage materials.

Silicon-Derived Compounds

Two silicone compounds were detected: dimethylsilanediol and tetradecamethylcycloheptasiloxane. Of everything found in this test these are the most significant foam contributors. They are aggressively surface-active, meaning they concentrate at the air-water interface and stabilize bubbles more effectively than almost anything else detected. They also ionize exceptionally well in GC-MS/MS (the test that was performed), which partially explains why they register such a strong signal despite likely being present in small actual concentrations.

Unlike everything else detected in this test, silicone compounds are not naturally found on the cannabis plant. The most likely culprit for these invading compounds is silicone based wetting agents used in foliar sprays during the cultivation process. Don’t panic, these compounds can only survive within water, and are removed in air drying and freeze drying process. This means they are not making it into your finished product. 

Bonus Testing: Free Available Nitrogen 

Outside of the main metabolomics panel, Caleb’s curiosity led him to performing an additional test for Free Available Nitrogen (FAN). This test measures the amino acids and small peptides.

"The liquid you provided had 53.8 mg/L or ppm of FAN present. This is not insignificant and is on par with nitrogen levels present in fruit juices and some beers. This could be important because it can impact flavor in a final product as well as indicate the amount of nitrogen being extracted during the hash process. We all have tasted cannabis smoke that has been fed too many nutrients!"

It is well known in the agriculture world that too much nitrogen causes plants like tomatoes to prioritize leafy vegetative growth over fruit and sugar development, which results in bland, bitter, or harsh tasting produce. While it may be fair to make this correlation in the flavor of the flower, our current theory is that it will not affect ice water hash the same way.

While the Free Available Nitrogen is notably high in the foam, it is worth noting that this is only testing the water/foam, not the hash. When ice water hash is being collected from a wash in the micron bags, we are only mechanically capturing the solids, not the liquids. The trichome heads and ice water hash is being rinsed thoroughly to wash through any chlorophyll or contaminants, which would include this high nitrogen water/foam. 

Our finding on this data point is interesting, however, it is our assumption based on experience of the process that it has no relation to the hash produced. 

What Tests Do You Want to See Next?

This was the first time, to our knowledge, that wash foam has been subjected to actual laboratory testing. While we have learned a lot there is still much left to explore and speculate on. 

We would love to hear what you think we should text next. Send us a DM on Instagram or send us an email with your ideas! We'll keep working with Tryptomics to find real answers to the questions the community is actually asking.