Decarbing the trim or flower activates the resins inside the material and not just the visible surface crystals. The oils in the butter draw the oils from the material into the liquid.
For example, my medical cannabis has 2 THC measurements. “Actual†and “Potentiallyâ€. The “Actual†is what is THC on the surface of the material. This can be as low as 0.27% of the weight / gram of flower. The “Potential†is the amount of THCa...THC(a)cid...it can be measured at 25% of the weight /gram of flower. It’s the THCa that needs to be decarbed to convert it to THC. (Same as CBD/CBDa). THCa has practically no similar effects to THC unless it’s been decarbed.
So to get the strongest potency of your butter you want to activate all 25% of the “Potential†THC otherwise your butter would be the very weak 0.27%. 😉 This hold true for almost all extraction methods using solvents such as butter/olive oil/Everclear alcohol.
And even better than making butter, is to turn your butter into ghee before adding your herb.
Best of luck ðŸ‘
Cheers
YYC