According to Wikipedia, the distillery was created in 1931, when Harel Frères bought the Mauritius OK Distillery. In 1939, with the difficulties of the WW2, the island had problems importing petroleum products and the distillery produced fuel as a substitute. The plant was later renovated to produce rum and other spirits and in 1980 a brand new distillery was built in Beau Plan that has been renamed Grays Refinery.
We start with two duos of single casks, one from 2009, one from 2007 and move over to another interesting trio ;).
New Grove 2009 “The Nectar” (54,7%): Nose: Drier and not as sweet as I expected. New Grove is always full of sweet peaches for me but this one is different, pretty much driven by the cask. Behind that a mix of dried fruits (peach, apcriot), sweet vanilla, some wood, fruit salad and candied fruits. Now, after about 20 minutes in the glass, I also get the full dose of the aforementioned peaches and the rum is getting sweeter by the minute. Don’t get me wrong, this is natural stuff, but the sweetness is approaching a point at which I don’t think I won’t be able to enjoy this rum anymore. Interestingly, after about an hour, the sweetness is almost gone again and the rum is now much more enjoyable Palate: Again quite sweet with fresh sugar, simple syrup and candied peaches but also more spicy notes such as pepper, oak or vanilla. With more time the palate is becoming drier as well, something that we are used to with the nose but we rarely ever find that with a rum’s flavour. We now get more and more tonka and vanilla, something that suits the rum pretty well. The finish is pretty much the same and what you get totally depends on how long you have given the rum in the glass. With less time, more fruity and sweeter notes, with more time drier and spicier aromas. A pretty crazy rum that requires some time getting used to. I feel like the character of the rum might be completely different again about two-thirds through your bottle. The score is hence only for the record. 
(82/100)
New Grove 2009 “Salon du Rhum” (59,7%): Nose: Interestingly, I do get something close to acetone and nail polish remover at first, but not in the lovely sense à la Hampden. Then artificial floral notes, toilet cleaner and aroma spray, some weird, non-natural sort of grapefruit and now also also the peaches. Meh… After about 45 minutes all of that has settled down a bit and I wonder what this might taste like. Palate: Oh my sweetness. I won’t say it is dosed, but the pure taste is one of very artificial sweetness. Candyfloss, sugar, simple syrup, candied peaches, mango, passion fruit and sweet oranges are my main associations. The palate is actually rather fun, just get clothespins for your nostrils. Finish: Very much on the sweet side with some spicy and woody notes here and there to back it up. It’s getting better! I bet some people who are more into rum-based spirits might love this but I just cannot, even though it isn’t exactly bad. If only it weren’t for that terrible, terrible nose… That actually makes me think that it might be excellent cocktail material… Don’t hit me, folks. (74/100)
That was a rather wild set of rums. On to 2007 then.
New Grove 2007 “La Confrérie du Rhum” (50%): Nose: Much more straightforward than these 2009s (fortunately). Peaches, vanilla, apple pie, wood, cinnamon, hints of pepper and perhaps even a whiff of herbs. Clearly the best nose so far as it’s inherently consistent. It’s not extremely complex but it really doesn’t have to be. Palate: Quite mellow and surprisingly bitter. This is pretty much the New Grove profile a like. I get a certain sweetness, peach, aromatic bitters, quite some wood, grapes, sweet and bitter oranges as well as something that reminds me of grain. That works for me! Finish: Medium long with Rooibos, peach and the different bitters we’ve encountered so far. Also quite some wood and rather mellow spices – very nice. Exactly what I am looking for with New Grove. If they can develop this particular style, New Grove would surely be climbing up the ladder! (84/100)
New Grove 2007 “LMDW” (60%): Nose: Extremely similar to that of the one for La Confrérie du Rhum (LCDR) and, the higher abv aside, I don’t think I’d be able to tell the rums apart in a blind tasting. At best we might add roasting aromas such as cocoa, but that’s something I can only find when looking for it very hard. Palate: I am not quite sure if the higher abv helps here. It makes the rum more intense, but less easy to drink. At the end of the day it really just doesn’t taste much different at all. Relatively speaking, we might be turning down the bitterness a bit and add the cocoa/ roasting aromas but that’s about it. The rums really just are incredibly similar. Finish: A bit shorter than that of the LCDR but more intense in a way. I get a mix of the fruits and aromas from the cask. Yup, that works as well but as I’ve said, it is essentially the same rum for me. (84/100)
New Grove Solera 25YO (40%): “Solera. Aged 25 years”. That’s what’s stated on the bottle. I won’t help you making sense out if that. The nose is sweet with almost candy-like peaches (i.e. this stuff) and it only keeps on getting sweeter. Then hints of sulphate/ matches, port wine-esque aromas (dried berries, raisins, gorp), vanilla and now even more of the Pfirsichringe (candy peaches). Tastewise, it is again really sweet and quite a bit more intense than we’re used to with 40% abv rums. The candy peaches and port wine flavours are the most obvious notes here and I am starting to wonder if they used fortified wine barrels for this one. I further get dry gum, coconut chips, candied, dried fruits (peaches, apricots) and more gelee-like flavours. The finish actually does contain some oak, is even slightly bitter and comes without the peaches, but with the port flavours. Interesting juice, I must say, even though I don’t think it is very good. The only problem is that I am not exactly sure how much we should attribute to the distillate and Solera (Shery is an obvious suspicion here, of course!), respectively. (68/100)
Now we’ve had some rather nice New Grove’s as well and this doesn’t come close to the distillery’s potential. Let’s try an indy bottling.
S.B.S Grays “Port Finish” 2008 10YO (55,7%): I am not sure if I’ve ever had an independently bottled Grays before. Nose: Wow, this is rich! I didn’t expect this. Lots and lots of dark and dried fruits (clearly grapes and raisins but also pears, plums and mixed marmelade if you want), almonds, tobacco, some spices such as ginger, cinnamon and vanilla. Very, very nice! Palate: I didn’t mention this but the nose left a rather sweet impression with me but this is dry! It starts again with the potpourri of fruits and the typical notes that come with good Port wine finishes (dried fruits such as plums and grapes, tobacco, leather). Then the spices from the nose again but they play a supporting role more so than anything else. The texture is incredible and a perfect balance of dry, creamy, fruity and the cask elements. The finish is quite long and intense, getting exceedingly dry but mainting the general character of the rum. The kings of finishes have done it again – the Port cask really enriched the rum and developed it close to its full potential! Well done/ chosen – this is so much better than everything else I know from the distillery! (87/100)
And last but not least, Johannes also provided some tasting notes…
New Grove (for Bar Lamp and Shinanoya) 2007 11YO (50%): Finally, my first rum review. It is a joint single cask bottling for the Japanese spirits trader Shinanoya and Mr. Nakayama, a rum aficionado and owner of the bar “Bar Lamp” in Tokyo. The rum aged in a limousine cask (French oak), which have smaller pores in the wood than the standard US Bourbon cask made of American white oak. Nose: I can smell some ripe fruit, a little oak, raisins. Overall, a pleasantly sweet smell. Palate: Directly a sweetness rolls along my tongue, opening-up a taste of ripe fruit, peaches, raisins, and fruitcake. After the initial sweetness, a slightly too alcoholic burn stays, unfortunately. The finish is beautifully long with ripe fruits and very clearly peaches. Really wonderful stuff! The Japanese really know how to select tasty things. If the alcohol had been integrated a tiny bit better I would have rated it even higher. (89/100)
Single Cask Rum 