I watered this dose to one part absinthe to 4.5 parts water, without sugar.
The initial color in the bottle is red, deep like a vine ripened tomato, but transparent.
The louche is amazing, nice oil trails and opaqueness that comes out easily. At about 1:1 the color has shifted from red to more of an orange creamsicle. At 1:4.5 the louche is still alive and the color is more of a rosé peach.
Pre-water aroma is anise and fennel rich, with a lot of alcoholic heat. Once the dose was prepared the aroma was strong on the anise, with few of the other absinthe herbs coming through.
The flavor is very nice if you're into anise-heavy absinthes. There's plenty of wormwood flavor and some other bitter herbs as well, but sweetness and bitterness seem to be dancing together with this absinthe, alternating between the two. It's pleasant and very refreshing.
The finish is a little tart with notes of citrus, but not mouth puckeringly tart. There's some lingering wormwood and anise, but it i very muted on the finish.
I really like this absinthe, it's one of my top favorite absinthe, and certainly my favorite rouge out of the two others that I've tried, "Amerique Rouge" and "La Matriesse". In both brands, they were unpleasantly tart while the louche was picky and needed a lot of coaxing. Absenta Serpis though, is exactly what I had in mind for what an absinthe rouge should be. I was hopefull the final color would have retained more of the vibrant redness from how it looks fresh from the bottle, but that is a tiny thing for me to hold against such a wonderful absinthe.

No sugar. Icy cold slow drip. This is from a sample provided to me from a bottle opened March, 2007.

Aroama pre-louche: Very light, with little standing out other than sweet frutiness. Not unpleasant, but no trace of the usual "absinthe" characteristics. This is going to be a tough one to rate. In the glass the aroma does not change. Candied fruit still tries to make its mark, but other than that, not much. Nice aroma, but weak.

Color: A crystal clear blood-red. Not the brilliant candy red I was expecting from stock photos. Actually, this appeals to me more since it may show some development of natural coloration, despite the fact that it has to be colored unnaturally. All in all, just what I would want a "naturally" colored absinthe to look like, strange as though that may sound.

Louche: slow trails develop quickly, and there is no cloud for quite a while. When it does come, it flushes through rather slowly. It is a beautiful display. The louche is thick and a rich orange-red. A very nice louche indeed. The aroma while louching is not strong, the pleasant candy scent is concentrated and smells very good.

Flavor: Very nice. I don't find this absinthe bitter at all. In fact, I find it very nice. It is not imposing in any one character, but has a surprising balance of subtle sweetness. This is precisely what I wanted a rouge to taste like. I can't put it any other way than that. Very subtle, very smooth, very straightforward.

Overall: I feel like I'm committing some sort of heresy by saying that this is one of my favorite absinthes. I was very wary after trying the only other rouge, but this is actually a very fine drink. I only have enough for two drinks worth, and so now I have to determine whether or not to try my second, and last glass with sugar for comparison, or without since I already enjoy it as is. I will most likely be buying a bottle of this in the near future!

This was one of the first absinthes I tried and is a nice satisfying drink at a decent cost. Whatever your opinion is about unnatural colors I still find it quite nice to have a red option in the cabinet. The louche is one of the most interesting points of this absinthe. It builds from the bottom and tendrils its way in interesting swirls. It finishes in a peach tint. Very strong on the anise with some striking fruity overtones its quite different from NS70 ( another Spanish offering) that uses mint. This is a good absinthe to introduce to beginners without breaking the bank in the process. At 30 Euros a liter, its a value. It does lack a herbal complexity but the fruity overtones gives it some of its own special merit. I liked it and I'd buy it again.

Bright, clear red color. The louche develops very quickly and is intriguing to watch. The aroma is odd, with an antiseptic smell that put me off a bit. Get past that smell and the taste is acceptable. Heavy on the anise, an acceptable drink. I've had worse, much worse, it's just that the aroma is annoying to me since I can't define it.

Bottle purchased and opened February 2006, review sample louched December 2008.

Serpis 65. What does one say? It's red, and it's heavy on the anise. Neat, it gives an aroma that is quite intriguing - alcohol accompanied by something like citrus and flowers, but not any flower you can identify. The color is striking - clear as crystal, like a red/orange candy diamond ring. Then the water is applied, and it turns peach. A beautiful, alluring peach. The aroma doesn't change, but gets smoothed out a bit - the alcohol drops into the background, and the flower/citrus aroma dominates.

The taste is bitter, wormwood, and anise. The finish is bitter and dry, and makes you want to take another sip to mitigate the bitterness. Sugar doesn't remove the bitterness, but I can't really imagine drinking this without sugar, it would be too damn bitter. It's surprising, but not unpleasant. The finish is long-lasting.

This is one of the strangest absinthes to have in your collection, but it represents a real value. The bottle is 1 Liter, and sells for less than $40 (plus shipping). Every connoisseur ought to have at least one bottle for the novelty.