夏天或许正在离我们远去，但是，满满一勺液态氮冰淇淋却是一整年都能享受的美味。

    液什么？

    液态氮冰淇淋。全美的冰淇淋制造商正在运用食品化学把这种人见人爱的甜品变成一种时髦的，高科技的，可定制的美味。

    只需厨宝（KitchenAid，美国著名厨房用具品牌——译注）搅拌器，同时配以液氮罐和奶油，就能把牛奶、糖和水果这类简单的配料在不到一分钟的时间里变成按需定制的冰淇淋。液态氮的沸点是零下320度，当它迅速蒸发时，会腾起一股《歌剧魅影》式（Phantom of the Opera）的白雾；同时，搅拌物的温度会骤然降低。当雾开云散，冰淇淋就大功告成了。

    这种疾速成型的过程提升了口感。弗吉尼亚理工大学（Virginia Tech）的科技系教授，化学家亚伦•戈尔斯坦解释说，快速冷冻意味着冰晶根本来不及形成。他说：“结果，它们的颗粒变得极其微小，从而使冰淇淋的质地更细腻柔滑，不是一咬一口冰碴。”

    因此，这一勺冰淇淋大行其道，从乔治亚州到亚利桑那州再到华盛顿州，零度之下冰淇淋公司（Sub Zero）和蓝天乳品店（Blue Sky Creamery）这样的小企业都深受其恩。现在，液态氮，加上奶油和几乎无穷无尽的口味正变成各地各类营业场所和餐饮服务公司大获成功的秘方。

    Summer may be ending but a good scoop of liquid nitrogen ice cream can be enjoyed year-round.

    Liquid what?

    Liquid nitrogen ice cream. Ice cream makers nationwide are using food chemistry to transform this favorite dessert into a funkier, high-tech, customizable indulgence.

    Using KitchenAid mixers tricked out with liquid nitrogen tanks, creameries turn simple ingredients like milk, sugar and fruit into made-to-order ice cream in under a minute. The blend rapidly chills as liquid nitrogen -- with a boiling point of -320 degrees -- instantly vaporizes in a billowing, Phantom of the Opera-esque fog. When the cloud evaporates, the ice cream is ready.

    The speedy process boosts taste. The quick freeze means ice crystals don't have as much time to form, explained Aaron Goldstein, a chemist and Virginia Tech professor. "Consequently, they're really small, which makes the texture of the ice cream seem more creamy and less icy," he said.

    The result is scoopable ice cream that has supported franchises like Sub Zero Ice Cream and Blue Sky Creamery from Georgia to Arizona to Washington state. Now, liquid nitrogen, plus cream and almost limitless flavor options are fast becoming a recipe for success for local parlors and catering firms.