The concentrates category booms in Colorado, Washington and Oregon, with no signs of flowing down. Within the world of concentrates, one category — vapes — eclipses all others, in terms of growth.

In one state, Oregon, vape sales absolutely dominate the market: vapes capture 62 percent of the Oregon market, compared to 34 percent in Colorado and 33 percent in Washington according to cannabis data analytics and market research firm BDS Analytics.

But differences between states and vapes extend beyond what share of the concentrates market vapes possess.

One interesting trend that has rooted firmly in Colorado is the rise of vape cartridges filled with THC distillate rather than oil.

When Colorado launched recreational sales in 2014, there is not evidence of sales of any vaporizers filled with distillate — 98 percent of sales were of oil cartridges, 1 percent were for disposable oil pens and the remaining 1 percent were miscellaneous. In 2015 market share of oil cartridges declined slightly to 91 percent while sales of disposable oil vape pens rose to 8 percent. And in 2015 we see the first evidence of distillate, which captured 1 percent of the vape market.

But during the course of 2016 we see distillate take off in Colorado. Through 2016, oil cartridge market share was down to 70 percent, while distillate rose to 18 percent. And this year distillate is catching up, with 28 percent of the market compared to 42 percent for oil. In June of this year, distillate’s market share rose to 30 percent, compared to 38 percent for oil.

The same trend is taking place in Oregon, where we are seeing consumer preferences shift rapidly. During January of this year, oil cartridges represented 84 percent of the vape market in Oregon; distillates owned 16 percent. In July, however, oil’s market share had fallen decisively to 59 percent, while distillate’s had risen to 35 percent.

Washington? The trend towards distillate is much less dramatic. In January of this year, oil cartridges commanded 76 percent of the market, with distillate grabbing 17 percent. In May, oil’s share of the market actually to rose to 78 percent, and distillate’s fell to 12 percent.

The differences between oil and distillate are, at least conceptually, similar to the differences between beer and a spirit like vodka. Beer is a low-alcohol brew that contains a lot of different compounds and plenty of water. To make spirits, grains, fruits or even vegetables like potatoes are fermented, forming a low alcohol mash. Distillers take the mash and run it through stills, which heat the mash until the alcohol reaches its boiling point (lower than water). The alcohol turns to vapor, rises in the still, and then condenses (returns to liquid form). The liquid then drops down into a vessel that contains it. A spirit is sort of like, for example, the alcohol in beer minus all of the other stuff — it’s mostly just alcohol.

To make THC distillate, technicians use machines to heat THC-infused oil (which otherwise gets used in edibles and concentrates) until the THC in the oil turns to vapor (which is quite a high boiling point). The THC vapor eventually condenses within the machine, and then drops down into a containing vessel. While it is not exactly 100 percent THC, it is awfully close.