接着前面侃。

有人问，那个四蒸四酿怎么讲？呵呵，四蒸可能是有的，四酿么，就又是浮云了。不过在具体说四蒸四酿之前，还想先把几件事搞清楚。

第一是酒的颜色。我前面贴的图，一般白兰地酒的颜色被形容成金色到金红色（见十一中的图），但金庸书中说是“酒殷红如血”。不过有的白兰地在酿造的过程中有“加色”（coloring）这道工序，所以血红大概也是可能的。

第二是“酒高于杯缘，却不溢出半点”。这个么，如果酿成的酒里面矿物质多，表面张力大，那么也是可能的。是虎跑还是趵突泉水，好像就是那样。

好了，终于可以说说这“四蒸四酿”了。先看看白兰地的制作工序：

As described in the 1728 edition of Cyclopaedia, the following method was used to distill brandy:

A cucurbit was filled half full of the liquor from which brandy was to be drawn and then raised with a little fire until about one sixth part was distilled, or until that which falls into the receiver was entirely flammable. This liquor, distilled only once, was called spirit of wine or brandy. Purified by another distillation (or several more), this was then called spirit of wine rectified. The second distillation was made in balneo mariae and in a glass cucurbit, and the liquor was distilled to about one half the quantity. This was further rectified—as long as the operator thought necessary—to produce brandy.

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Technology

Except for few major producers, brandy production and consumption tend to have a regional character and thus production methods significantly vary. Wine brandy is produced from a variety of grape cultivars. A special selection of cultivars, providing distinct aroma and character, is used for high-quality brandies, while cheaper ones are made from whichever wine is available.

Brandy is made from so-called base wine, which significantly differs from regular table wines. It is made from early grapes in order to achieve higher acid concentration and lower sugar levels. It generally contains smaller amount (up to 20 mg/l) of sulphur than regular wines, as it creates undesired copper(II) sulfate in reaction with copper in the pot stills. The yeast sediment produced during the fermentation may or may not be kept in the wine, depending on the brandy style.

Brandy is distilled from the base wine in two phases. In the first, large part of water and solids is removed from the base, obtaining so-called "low wine", basically a concentrated wine with 28–30% ABV. In the second stage, low wine is distilled into brandy. The liquid exits the pot still in three phases, referred to as the "heads", "heart" and "tails" respectively. The first part, the "head," has an alcohol concentration of about 83% (166 US proof) and an unpleasant odour. The weak portion on the end, "tail", is discarded along with the head, and they are generally mixed with another batch of low wine, thereby entering the distillation cycle again. The middle heart fraction, richest in aromas and flavors, is preserved for later maturation.

Distillation does not simply enhance the alcohol content of wine. The heat under which the product is distilled and the material of the still (usually copper) cause chemical reactions to take place during distillation. This leads to the formation of numerous new volatile aroma components, changes in relative amounts of aroma components in the wine, and the hydrolysis of components such as esters.

Brandy is usually produced in pot stills (batch distillation), but the column still can also be used for continuous distillation. Distillate obtained in this manner has a higher alcohol concentration (approximately 90% ABV) and is less aromatic. Choice of the apparatus depends on the style of brandy produced. Cognac and South African brandy are examples of brandy produced in batches while many American brandies use fractional distillation in column stills.

http://en.wikipedia.org/wiki/Brandy

上面是白兰地的做法，简单地说就是葡萄榨汁，然后发酵，形成“base wine”。蒸馏第一遍以后的产物叫“low wine”。再蒸馏一遍甚至几遍，出来的产物叫做“spirit of wine rectified”，也就是白兰地。而干邑白兰地（Cognac），则一定要蒸馏两遍。蒸馏好了以后，这白兰地还有放在橡木桶里存放（醇化）起码两年，然后经过勾兑，才是最后的产品。关于勾兑，我后面再详细说。

所以呢，这白兰地“四蒸”，也就是蒸馏四遍，是可能的。我们再来看看书中的描写，接着前面：

    丹青生道：“喝酒，喝酒。”又倒了三杯，他见令狐冲不问这秘诀，不禁心痒 难搔，说道：“其实这秘诀说出来不值一文，可说毫不希奇。”令狐冲知道自己越 不想听，他越是要说，忙摇手道：“前辈千万别说，你这三招剑招，定然非同小可。 以如此重大代价换来的秘诀，晚辈轻轻易易的便学了去，于心何安？常言道：无功 不受禄……”丹青生道：“你陪我喝酒，说得出此酒的来历，便是大大的功劳了。 这秘诀你非听不可。”令狐冲道：“晚辈蒙前辈接见，又赐以极品美酒，已是感激 之至，怎可……”丹青生道：“我愿意说，你就听好了。”向问天劝道：“四庄主 一番美意，风兄弟不用推辞了。”丹青生道：“对，对！”笑咪咪的道：“我再考 你一考，你可知这酒已有多少年份？”

    令狐冲将杯中酒喝干，辨味多时，说道：“这酒另有一个怪处，似乎已有一百 二十年，又似只有十二三年。新中有陈，陈中有新，比之寻常百年以上的美酒，另 有一股风味。”向问天眉头微蹙，心道：“这一下可献丑了。一百二十年和十二三 年相差百年以上，怎可相提并论。”他生怕丹青生听了不愉，却见这老儿哈哈大笑， 一部大胡子吹得笔直，笑道：“好兄弟，果然厉害。我这秘诀便在于此。我跟你说， 那西域剑豪莫花尔彻送了我十桶三蒸三酿的一百二十年吐鲁番美酒，用五匹大宛良 马驮到杭州来，然后我依法再加一蒸一酿，十桶美酒，酿成一桶。屈指算来，正是 十二年半以前之事。这美酒历关山万里而不酸，酒味陈中有新，新中有陈，便在于 此。”向问天和令狐冲一齐鼓掌，道：“原来如此。”令狐冲道：“能酿成这等好 酒，便是以十招剑法去换，也是值得。前辈只用三招去换，那是占了天大的便宜了。”

http://www.shuku.net/novels/jinyong/xiao/jhu19.html

看清楚了？这酒原来是三蒸，从吐鲁番运到杭州以后，丹青生又蒸了一次，是为四蒸。但是金庸把随后的存放也称之为“酿”，这就值得商榷了。因为我们平常的理解，“酿”指的是发酵的过程。随后的存放，虽然化学反应还在继续，但并不称之为酿，尤其是在蒸馏以后，酵母菌根本无法再起作用，这点我前面也提到过。一蒸馏，把原来酒中不能挥发的物质比如说糖、盐之类的都留在蒸馏后的残留液中。如果原酒中还有酵母菌的话，也不会挥发，而是留在了残留液中。就算另加酵母，也因为蒸馏后的白兰地中的酒精浓度太高，发酵不可能继续。所以说，四酿是不成立的。那么有没有四酿呢？有，不过不是在制作白兰地的过程中，而是在做白酒的时候可能有四酿。不过这又是个大题目，今天太晚了，且听下回分解吧。

但是在呼呼之前，还想说的就是前面提到的酒的年份，在这里又成了故事的关键。前面在洛阳城绿竹翁那里学到的知识，在这里派上了用场，而且还让丹青生折服。不过我觉得不该叫年份，因为在现代，“年份”这个词代表的是另一个概念，或许叫“年岁”更合适。