“Nobody Said There Would Be Math!”
Water, water, everywhere, and I didn't stop to think... Ratios? Proof? ABV? How does it all relate, interact, and affect my enjoyment of my absinthe? Well... let's not get all carried away here, since people have been managing to enjoy absinthe for some 200 or so years now. Ratios, and generalizations about ratios have served us fine, but if your predilections place you amongst the nerdier of us, you may want to take a look at this “Absinthe Dilution Matrix”.
The impetus for this is twofold:
1. The realization that many people who drink absinthe simply default to the “3 to 5 parts water” formula, without regard to the specific absinthe's bottled abv (alcohol by volume) and
2. My opinion, after much research (read “imbibing”), that it is almost universally consistent that high quality absinthes show most correctly at a final (diluted) abv of between approximately 11% and 12.5%. This sentiment is echoed by one of the more erudite in our midst, and is supported by historic information.
The highlighted area in the figure below is this approximate “ideal range”. Those posting reviews on this site should consider watering review samples to this range, and base scoring on that preparation. If your preferred mix is different, that can always be noted in the comments. Notice the way the highlighted band moves, with increasing abv, and dilution. And if your preferred mix is stronger (less water) or weaker (more water), those final abvs move the same, as well. As an example, you can see a ratio of 4:1 with a 53% absinthe might be too much water, and with a 72% absinthe, might be too little.
So, I hope this helps. At the very least, perhaps you are now better aware of the differences that small ratio changes make. Most of all, have fun, and enjoy your absinthe. Now if you'll excuse me, I think I'll louche up a La Coquette to 13.09%!
You may also find this little gizmo handy: