Russian Imperial Stout 的風行，雖有風風光光的歷史舞台，也不如說是謎一般的酒風。由於釀造與熟成的方法自古就十分多元，到今天，用新舊發酵方法、與迥異釀造配方作詮釋的酒廠產品更是多如繁星：極為舊式 - 使用開放式發酵槽並以舊木桶陳年 - 的傳統RIS，在今天以Harvey's Le Coq Imperial Double Stout 2003年版(右下圖)還可以一窺究竟；同時，許許多多的創意都以新橡木桶或舊葡萄酒/烈酒桶作熟成媒介，譜成所謂的『桶陳板』。

其實，以各酒種說來，用RIS作桶陳還真是幾近完美的選擇，因它的酒質十分沉厚、風味複雜，耐得住新舊酒桶內部各式各樣的影響源與基酒作有機式地交匯，交響出更有層次、卻不失原調的新特色。(上圖便是以巨大的新橡木桶熟成，在2010年的GBBF-BSF吧接汲口直接倒出的荷蘭超棒小酒廠De Molen的RIS，成品香蕉油、苦可可、香草籽味十足)

底下嚐的兩款，一是丹麥小酒廠Midtfyns Bryghus作的超前衛詮釋，混合了一些Baltic Porter常用的風味配方；而另一款，是英國倫敦 - 矢志以現代重酒花的韻律重現源自倫敦老酒風格 - 的The Kernel小酒廠的限量作品。

放在一起品嚐比較，看看21世紀的兩款詮釋會帶給我甚麼樣的感官刺激、能否再次讓凱瑟琳皇后縱情驚艷？

Midtfyns Bryghus (Denmark), Imperial Stout, 9.5%abv. (MBIS) vs. The Kernel (UK), Imperial Stout, 12.5%abv. (KIS)

Background Info.

MBIS: Purchased at the BSF bar, GBBF 2010; bottle-conditioned in a long-neck 500ml brown bottle, BB 14/01/2011. Served cool (11~13ºC) in a slim short-stemmed goblet.

KIS: Purchased at the Kernel Brewery in London, this is a new product according to the staff. Bottle-conditioned in a 330ml brown bottle, with a “date of birth” printed on the beer label – brewed on 29/09/2010. Served cool (11~13ºC) in a slim short-stemmed goblet.

Appearance

4/5 MBIS: pitch black, coming with a 2cm thick dark beige froth sustaining for a short while, before settling to a thin sheet; the carbonation comes light enough, as evinced by sparse bubbles attached to the side of the glass.

4/5 KIS: pours a lubricating or semi-oily pitch black body, coming with a very thick and frothy dark tan head with extremely good retention; the carbonation is light.

Smell

3.5/5 MBIS: upfront on the first sniff comes malty and sweet candy-ish aroma, mixed with random notes of sweet dates and marinated black plums, a bit like a darker version of barley wine, really; given a good swirl, notes of sweet wood, treacle, sweet herbal drink and more ripened berry fruits (like smoked longan fruits) spring to mind, underlined by an aromatic flow of hoppiness in the background. But the roastiness is somewhat in the lacking, as far as a RIS is concerned. Once the beer head completely settles, the aroma is predominantly sweet malty. More like a barley wine brewed with black malts, really!

4/5 KIS: the deeply roasty and coffee-ish notes dominate the first sniff, decorated with refreshing aroma of fruit esters (both sour and fragrant) and hop bouquet (citrusy)… A swirl brings out leather, sweet wood, a touch of sweet soy sauce, lightly overripe melon-ish esters and warming alc. Deep and enchanting, but not really complex. As the beer breathes for a while, the hop aroma vanishes in intensity and gives way fully to the jammy, roasty malty theme.

Taste

4/5 MBIS: dare I say, the taste is much better than the nose – semi-sour & sweet plum-ish as well as semi-smoky upfront; plenty of black malts abound, backed by a marvellous length and depth of spicy hop input. Dry-ish in the finish, aromatic, burned-nutty and only remotely coffee-ish, but always with a distinctive edge of aromatic malts as in barley wine or more malt-dominated beers. As the temperature turns higher, the finish is herbal, lightly stale-ish almost in Oloroso’s fashion… Compared with the more orthodox KIS, MBIS tastes more like a continental black malty drink, very hard to be related to the style RIS to me.

4/5 KIS: a flow of thick, almost syrupy, intake of sweet coffee, date jam, ripe fruit esters, and warming from the beginning… It’s really potent, and yet the hop presence also radiates a semi-chewy feel towards the back of the tongue, so robust that it’s more like an American take on the style, which is, showing much more hop weight than traditional English roasty+fruity+stale-ish ones. Compared with MBIS, the taste is far richer and heavier, but the finish is neither as clear nor evolving, while a burned-nut syrupy aftertaste lingers nicely. Also, the flavour structure is not as lively or evolving as MBIS.

Mouthfeel

4/5 MBIS: softly carbonated and simultaneously refreshing, medium-plus bodied, very easy to drink actually, with an outstanding depth buttressing a mild but attractive, structured flavour profile.

4.5/5 KIS: lubricating, even oily in terms of texture, the body is fulsome and the flavour gives no compromise.

Overall

3.5/5 MBIS: I can’t rate/appreciate it in the same way as I do KIS, in that this beer really is more unconventional for the style RIS. But, all in all, I find it delicious and intriguing enough, witnessing the brewer’s craftsmanship shown vividly in my glass and on my palate, for sure~

4.5/5 KIS: the fact that this high gravity ale, before consumption, had stayed in the bottle for merely 3 months, might shed some lights on the rich yet somewhat less clearly defined theme that a mature and robust RIS would’ve shown otherwise. That said, I find a lot of ageing potential in this product – there’s no doubt. It is a wonderful drink to have on the second day of the New Year 2011, and definitely worth revisiting!

--Yau (tasted 02/01/2011, notes transcribed 22/03/2013)