tincture is not an essence
>What is the difference in potency between a triple distilled herbal essence and a double strength tincture? Would they give the same results?
The two are not comparable.
When you distill an herb you only get the volatile fractions. That's the essential oils.
In a tincture you only get the fractions that are soluble in the menstruum; usually that's the alcohol- and watersoluble fractions.
One part of a double strength tincture is always weaker than two parts of a "normal" tincture. It's inherent in the making of it. Unless, of course, you're talking fluid extract, in which case the 1:1 strength is the result of considerably more than double the amount of herb.
Let's see if I can make that easier to understand. You have several ways to make a double-strength tincture, of which only one is feasible, and that gives you lousy quality:
One is, use the same menstruum on two batches of herbs, ie. make a tincture and use this tincture on more crude herb. Your quality will be lousy, because your menstruum (the tincture, on the second pass) will pop off the most fragile constituents (alkaloids mostly) back into the crude herb, AND will pick up celluloses, tannins and the like that are more robust and can throw out more fragile constituents in a tincture.
One is, make your tincture and evaporate off half of its volume. Only if you do that you'll have to freeze your tincture in order for it to keep, as you've just boiled off all of the alcohol, most of the volatiles, and some water. And thus defeated one of the "whys" of tinctures.
One is, use double the normal amount of herb in your tincture. If you've ever made a 1:2 fresh herb with 95 % alcohol you know that this is impossible. You simply cannot get the alcohol to cover that much herb. The same goes actually for a 1:5 dried herb with 50-70 % alcohol; 100 g dried herb have about the same volume as 5 dl fluid.
A fluid extract is a different matter. You set it up by percolating a certain amount of a normal-strength tincture; continue your percolation to get a certain amount of a very weak tincture (the marc is in principle exhausted after the first perc). Evaporate off 90 % of the resulting second fluid. Combine the two, and if you've done it right you have a quality fluid extract, ie. a 1:1 tincture instead of the normal 1:2 (fresh) or 1:5 (dried).
Tinctures are not made by distillation. I assumed this to be the case perhaps 15 years ago, too, and tried to find a cheap still in order to make tinctures. Heh. Long ago ...
Tincture-making is far easier than that. For tinctures a simple glass jar, or a glass jar and a sawn-off bottle, is all you need. It's for essential oils you need a still, and those (both the EO's and the stills) are quite expensive.