We’re probably all familiar with the belief that cannabis flower burning to “white ash” indicates it was grown right or is otherwise good bud. Similarly, we likely all know the old-school belief that holding in a hit gets you higher (“if you cough you don’t get off”), which was disproved by research over 30 years ago.
So if the long-held belief that holding in hits gets you higher is not true, yet persists, what about white ash?
Is there something about bud that burns to white that makes it better than bud that burns to black?
Common white ash theories
People who felt a growing step called “flushing” was the cause of white ash and a sign of good bud;
people who felt it was a measure of moisture in the bud (too moist bud = black ash);
and people critical of the entire premise.
“A properly grown bud flushed of nutrients with water for the last 10 days of growth will give you a white ash when the bowl is cashed.”
“White burning ash (from anything burning) indicates a clean combustion. You can think of campfires you might have watched. If the wood is green, it leaves a chunky charcoal.”
The ‘flushing’ controversy swirls
While there is some divide over what white ash signifies, there is pretty wide consensus around the importance of a weed grower’s common practice called “flushing.”
Hydroponic indoor growers “flush” the plant for the last 10 days before harvest by only feeding it water, instead of a nutrient mix.
Some growers compare flushing cannabis with water to fasting for people, “It forces any stored nutrients to be used up by the plant and triggers a push to ripen.”
However, well-flushed flowers that are rushed through the drying and curing process will not burn perfectly.
But what does the research on flushing say?
Flushing science is thin. There isn’t much research that supports this concept, and there is a Master’s Thesis out there which found flushing to be ineffective in removing any significant amount of nutrient from the bud.
It specifically points to a lack of “double-blind studies that have been performed to test the efficacy of flushing,” but notes that despite that absence of research, “the overwhelming majority of cannabis growers flush.”
Many of us Cannabis consumers, myself included, feel that we can taste a poor flush when smoking flowers.
Why wet weed won’t burn white:
While the majority of cannabis growers flush and it is a concern for some consumers, others wonder if black ash may be the result of too much water, rather than not enough.
Despite being able to taste the difference in flushed vs. not flushed flowers, black ash is a sign of incomplete combustion, and I’m not aware of a plausible explanation that a cause of poor combustion would be a poor flush.
Here listed are the potential reasons for incomplete combustion, such as:
too much moisture in the flower (as is the case with a poor dry and cure);
a poorly rolled joint;
or a really resinous flower.
Taste, not ash color, is a better indicator of good bud.
Of bowls and black ash
White ash may not have as much to do with the bud itself, but how it is smoked, specifically, in a joint or a blunt.
Joints/blunts also heat the material that is about to be burned, vaporizing both the resin and moisture in that part of the bud, which means that two of the major contributors to an inefficient combustion—and therefore black ash—are removed from the equation, or at least reduced before that part of the joint even combusts.
Additionally, the airflow is much more optimized for an efficient combustion in a joint vs. a bong or bowl.”
That is why pipes tend to burn black while joints burn white.
It really comes down to if you like the smell, taste, and the high—not the ash, it seems.
White ash on its own is an insufficient proxy for quality; there’s too many other factors at play. (I mean, cigarettes burn pure white, and no one’s Instagramming their Camel Lights.)
So if it burns white and you like it—great! If it doesn’t—that can be OK, too.