This study focuses on particle sizing and the potential effects it has on the molecular makeup of milled cannabis, extract quality and efficiency in SFE.

1. Size Matters: Optimizing Cannabis Milling
Blake Grauerholz, Solomon Ontiveros, Dr. Markus Roggen
Size Matters: Optimizing Cannabis Milling
Blake Grauerholz, Solomon Ontiveros, Dr. Markus Roggen
ABSTRACT
Does Milling improve extraction or destroy the cannabis? We postulated that the surface area to
volume ratio of cannabis would affect CO2 extraction efficiency and speed. Therefore, we
wanted to investigate the changes to terpene and cannabinoid composition in both the raw plant
material and extract as a function of particle size and shape. For this study cannabis flower was
ground to varying particle sizes using a milling system, along with other, less sophisticated,
milling methods to study the effects on our extraction method. This milling study is a further
piece of the puzzle of our extraction optimization project. By testing the extract oil and spent
material, an ideal balance of efficiency and terpene preservation, while preventing degradation to
the starting material, can be achieved.
INTRODUCTION
A) Particle Study (200rpm):
1 Food Blender
2 0.5 mm
3 1 mm
4 2 mm
5 4 mm
6 6 mm
7 10 mm
8 1 mm (700rpm)
9 10 mm (700rpm)
10 non-ground (baseline)
B) Extraction Study (3kg)(580rpm):
1 Food Blender
2 2 mm
3 6 mm
4 10 mm
5 non-ground (baseline)
C) Column Behavior Study (4kg):
1 Gravity Feed
2 Light packing middle & top
3 Tightly pack entire column
Cannabinoid profile on post-extracted
core samples taken from column:
Top (1)
Middle (2)
Bottom (2)
RESULTS
Non-ground offers no precision and greatly reduces efficiencies in SFE.
Smaller particles give higher cannabinoid and terpene yields.
Milling has little affect on terpenes and molecular makeup of cannabis.
METHODOLOGY
To study the effect milling has on freshly dried cannabis, a homogeneous mixture of whole
plant material was ground from 1mm<10mm using a Fritsch P19 milling system. A mixed
particle size produced with a food processor, and an analysis of un-ground material was also
studied. Additionaly, the RPM of the milling system was also varied in order to investigate the
potential of thermal degradation caused by the increased rotor speed. Lab testing was
performed on pre & post milled material. A selected range of particle sizes was used for CO2
extraction at normal production parameters to study the effect milling has on cannabis oil
yield and composition in SFE.
Once a ideal particle size is selected for extraction, the packing density of the cannabis
within the extractor vessel can be studied to further improve recovery of THC.
Every run of particle sizing and extract fractions were analyzed for total cannabinoid and
terpene content.
DISCUSSION/CONCLUSION
- Insignificant effect on decarboxylation at higher RPM or smaller particle sizing
- Recovery of both terpenes and cannabinoids is increased with decreased particle size (Fig. 1-2)
- Finer, more uniform, particle sizing provides better precision in extraction
- The cannabinoid fraction is of higher quality with smaller particle size (Fig. 6)
- The terpene fraction appears to improve in quality with larger or irregular (Blender) particle size.
- Further optimization on CO2 extraction effeciencies can be achieved by milling.
- Packing density has an effect on total recovery, gravity fed being best for our machine (Fig. 3)
For more information on OutCo products, please visit: www.OutCo.com
MILLING TECHNOLOGY
0
0.2
0.4
0.6
0.8
1
1.2
1.4
N
on-G
round
Food
B
lender0.5
m
m
1
m
m
2
m
m
4
m
m
6
m
m
10
m
m
1
m
m
(700rpm
)
10
m
m
(700rpm
)
% wt. Terpenes by Size
20
22
24
26
28
30
32
34
Non-Ground Food
Blender
2 mm 6 mm 10 mm
%Recovery
Cannabinoid Recovery by Size
75
80
85
90
95
Non-Ground Food
Blender
2 mm 6 mm 10 mm
%Recovery
Terpene Recovery by Size
30
35
40
45
50
55
Non-Ground 2 mm 6 mm 10 mm
%conc.
Terpene Concentration F1 (Food Blender*)
Food
Blender
Fig. 1 Fig. 2
Fig. 4
Fig. 5
55
60
65
70
75
Non-Ground Food
Blender
2 mm 6 mm 10 mm
%conc.
Cannabinoid Concentration F2 (2 mm*)Fig. 6
Fig. 3
StartFullHalfLoose
Flow

1 2 3 4 5 6 7 8 9
% wt. THC