Heres my initial report of the results of my PGA-extraction experiment with two pipe tobacco blends Id previously extracted---Hearth & Home Magnum Opus and Milan Sultans Blend. A later report may follow if steeping of either the extracts or NET liquids made from them alters the results.
I used exactly the same tobaccos for my cold extraction with PGA and my earlier PG/VG heat-assisted extraction. Literally, the tobacco for each of the respective pairs of extractions was from the same one-ounce sample that I ordered online---I started with 1/2 ounce of the tobacco both times.
The new macerations used about 50ml of Everclear (pure grain alcohol, 180-proof) to cover the tobaccos in each jar. Then the sealed jars sat on my kitchen windowsill for five days after which I filtered out the solids and particulates using my French Press single-pass dual-stage wire mesh/5-micron poly felt method. I poured the remaining solvent---which in both cases was a light caramel color---into a pan that I heated to about 130° on the stovetop to evaporate 80% of the alcohol. That was accomplished for each extract after about 15 minutes. What was left was about 10ml of extract concentrate. I poured into the pan 40ml of PG and stirred/scraped the stainless steel pan to assure thorough mixing.
Surprisingly, the mixed liquid was not entirely uniform and smooth. Tiny globs of darker stuff remained. From what I could tell, I think these were oil droplets rather than cellulose particulates. Theres a chance that they were concentrated globules of flavor, but I didnt want them in the extract, so I got out my trusty one-cup Melitta cone filter, slapped in a paper coffee filter, poured in the extract, globules and all, and let gravity do its job. After 20 minutes, I had a glass with about 45ml of medium-caramel-colored extract. The Magnum Opus extract is a shade or two darker than the Sultans Blend. Each extract is slightly aromatic with a scent that's consistent with its flavor. Both tobaccos are English blends with a complex mix of tobaccos (rather than being Latakia-heavy).
I got out my 30ml bottle of Sultans Blend NET made from the PG/VG heat-assisted maceration I did back in November 2013, nine months ago. That bottle of juice was made using 15% extract, 22mg nic, in a 40pg/60vg base, and is quite dark. I was still using doubled paper coffee filters at that point, and the NET liquid is a moderate gunker, but quite tasty. Then I made up a 3ml bottle of the new Sultans Blend, using 26% extract, 12mg nic, with an overall base blend of 30pg/70vg. I tried 15% extract initially, but the flavor wasnt strong enough, so I added drops until I was happy with the flavor, which was at 26%. Even at that high extract percentage, however, the color of the mixed juice remains a pale caramel transparency.
Next, I set up a drip test with two VAMOs set to 9 watts using JoyeTech 2.3 ohm 510 atties, to compare the two juices head-to-head.
Obviously, this cage match leaves something to be desired in terms of scientific objectivity---Im not only comparing juices made from different extraction methods, but also divergent extract percentages (26% versus 15%), unequal nic strengths (12mg versus 22mg), and extremely different ages (fresh versus nine months old). Thats OK, though. We do the best we can with what weve got.
Although the two juices were made from identical tobacco and share the same basic flavor profile, both the taste and the overall vaping experience are very different.
The fresh PGA-based cold extract juice is lighter. I dont mean that it has less flavor, but that the flavor comes through with a lightness and buoyancy. The nine-month-old PG/VG-based heat extract juice is decidedly more blunt and compressed in flavor, with less range---more bass notes and not nearly as much treble. I like the new juice better, but Im not sure if thats a fair comparison, given the advancing age of the older juice, which may be past its prime.
I also like the fact that the new NET juices are light-colored, as are most of my recent extraction batches filtered with the 5-micron French Press method. All my 2013 macerations are darker and obviously gunkier in their effects on coils/wicks. For reasons I dont understand, re-filtering my older extracts with the 5-micron French Press doesnt seem to clarify them much or lighten up their color. I tried re-filtering one or two, then stopped, because it was a waste of time and about 1/4 of the extract.
I havent yet made up a juice sample from the new Magnum Opus, so the head-to-head comparison with that tobacco might be different. If so, Ill post about it later.
So far, Id say that the PGA experiment is a success, all things considered. Will I do more PGA-based cold macerations? Right now, Id say yes. PGA macerations are less efficient, with much lower yields (If Sultan's Blend is a representative example, then PGA extract makes only 1/4 as much mixed juice as similar PG/VG heat-assisted macerations). Also, the cost per ml of juice is much higher with PGA extractions. Its still relatively inexpensive and easily affordable, however, and I sure do like the lovely flavor the Sultans Blend PGA-maceration produced, even though having to filter twice was a pain.
I hesitate to draw too many firm conclusions from this experiment, for all the obvious reasons. Ill need more data and further experience to make those judgments. Ill probably try a couple of Rocky Patel cigars with PGA-based cold maceration next.
