Notes on Decarb Method, Temp, and Duration
I won't bother collecting quotes from previous messages, but I'm addressing the recent discussion in this thread about differences of opinion on decarb times and temps. Hopefully what I write will make sense.
Anyhow, being a chemical reaction, one would think there would be little room for discussion on the matter, as there would be some ideal combination of time and temperature, and that would be that.
In reality, it isn't quite so simple. While there is indeed a relatively small sweet spot (or perhaps line?) in the graph, there are additional complications. And this is where we get such wide variations in the recommended time for any given temperature.
The common variables that are usually charted and most of us are familiar with are time and temperature. As temperature increases, time decreases. Personally, I like the 212-220 degree range. Why? Because any cooler than that and the times involved become impractically long. Go much higher and the times become much shorter, which means timing becomes far more critical. Also, if you have no other means of precisely controlling temperature, you can use boiling water to maintain a pretty constant 212 degrees. Or, for us MBM owners, the machine has a convenient 220 degree setting. That makes 212 or 220 degrees popular and convenient temperatures.
It would seem that now, having chosen a temperature, it should be a simple matter to consult a graph or table to determine the time needed. Or not. Enter the third, and often overlooked, variable: Method.
Your product needs to be held at a particular temperature for a certain period of time, which is not exactly the same as placing it in an environment of a particular temperature for that length of time. It can be loosely compared to something the all of us on this forum are familiar with - vaporizing. Different methods - conduction vs convection, for example - behave differently. This could be likened to immersion vs oven decarb.
Decarbing in oil allows the organic material to be quickly, evenly and thoroughly heated. Especially in the MBM, where the material is effectively pulverized, maximizing saturation and contact with the oil, ensuring complete and consistent heating.
With oven decarb, OTOH, you are dealing with placing whole material, in air, inside of some sort of container, in a box of hot air. The transfer of heat, through the air, through the container, and through even more air, and then throughout the biomass, is a slower, less efficient process. Given the same temperature, it will take longer, or given the same time, will require a higher temperature, compared to immersion decarbing.
Let's use cooking as an example to further demonstrate. It takes longer to bake a whole potato in the oven the oven than it does to cook French fries (chips) in oil - for exactly the same reason - conduction vs convection. So wrapping buds in foil or (slower yet) in a glass jar or baking dish in the oven will take longer to decarb than pulverized weed soaked in hot oil.
That's why my 220 for an hour in the MBM works just as well as someone else's 230 for an hour-and-a-half in the oven.
TL;DR? Different methods of decarboxylation work at different times and temperatures. Figure out what works best for you and go with it!
. To be fair is never searched for it before, either, and it's hard to search what you've never thought of searching for. Does that make sense? Cause it sorta doesn't from my seat... It's been a long, but great, day!
