英語聽力文摘 白蘭地是這樣釀成的

Brandy From Wine： How Alcohol Is Turned Into Brandy?

白蘭地釀造工藝精湛，特別講究陳釀時間與勾兌的技藝，其中陳釀時間的長短更是衡量白蘭地酒質(zhì)優(yōu)劣的重要標(biāo)準(zhǔn)。干邑地區(qū)各廠家貯藏在橡木桶中的白蘭地，有的長達40-70年之久。

世界上有很多國家都生產(chǎn)白蘭地，如法國、德國、意大利、西班牙、美國等，但以法國生產(chǎn)的白蘭地為品質(zhì)最好，而法國白蘭地又以干邑和阿爾瑪涅克兩個地區(qū)的產(chǎn)品為最佳，其中，干邑的品質(zhì)被舉世公認(rèn)，最負(fù)盛名。

既然有如此好酒，就一起去聽聽這些玉液瓊漿是如何釀成的吧。

From wine to Brandy on this Moment of Science.

Making wine is a biological process. Live yeast added to grape juice digests the juice’s sugar giving off alcohol as a byproduct. How much alcohol is produced depends on how much sugar the juice starts with. But eighteen percent alcohol is about as strong as any wine can get before the yeast poisons itself and the fermentation stops.

Brandy begins as wine but is then distilled, raising the alcohol concentration to forty or fifty percent–well above the level that would kill any yeast.

To see how distillation works, picture steam from a kettle hitting a cold windowpane, where it condenses and drips off. The water dripping off is called “distilled water,” which is different from tap water because it no longer contains the salts and minerals with much higher boiling points, which were left behind when the water in the kettle turned to steam.

Wine is roughly one part alcohol to five parts water, but the boiling point for alcohol is only 173 degrees Fahrenheit- 39 degrees lower than the boiling point for water.

So the alcohol in wine can be distilled into brandy by heating the wine to just over 173 degrees — hot enough to boil the alcohol, but not hot enough to boil the water.

The steam, which is mostly alcohol, is then run through cold tubing where it condenses and drips into a container.

Although the water doesn’t actually boil, some water still evaporates with the alcohol which is why even the strongest liquor is not a hundred percent alcohol. But most of the water is left behind. Making wine is a biological process which is legal in most states. But remove the water to make brandy, and you’re committing a federal offense.