听力文摘：老式冰淇淋机

Old Fashioned Ice Cream Makers²

老式冰淇淋机

Have you ever seen an old-fashioned ice cream maker¹?

你是否见过冰淇淋机？

Nestled inside the wooden bucket, there's a metal canister with a hand crank on top.

这种冰淇淋机带有木桶，而木桶内安装了一个顶上带手摇曲柄的金属罐。

Cranking the handle scrapes the sweet, creamy mixture from the sides of the metal canister, which sits in a bath of ice water and salt.

摇动手柄将糖和奶油的混合物从泡在冰盐水中的金属罐的一边挤出来。

But what does salt have to do with freezing?

但是盐在冰冻过程中有什么作用？

Why not just use plain ice water?

为什么不是只使用淡冰水？

The bath of salty ice water freezes ice cream faster than plain ice water could.

盆中的冰盐水能比淡冰水更快的冻结冰淇淋。

And speedy freezing does more than minimize the cranking time on a hot summer's day.

在炎日的夏天，快速制冷能够最大限度的减少摇动手柄的时间。

A fast freezing process also yields small crystals, insuring a silky texture³.

快速制冷过程也能够产生微小的冰晶，确保丝滑的口感。

Slower freezing could make big crystals with an unpleasant crunch⁴, kind of like ice cream that's gritty with freezer-burn.

较慢的制冷过程则形成大的冰晶体，使口感变差，似乎冰激凌表面因为冷冻变硬了。

The coldest that salt less ice water can get is 32 degrees Fahrenheit⁵, where there's a balance between the rates of melting and freezing.

含有少量盐的冰水温度最低可达华氏32度，这一温度是凝固和融化的平衡点。

Add salt to the mix and the energy balance tips, allowing the temperature to drop below 32 without freezing.

将盐加到最大量能打破能量平衡，使得温度低于32度而不结冰。

Let's say you toss a handful of salt into ice water, and the temperature drops to 20 degrees.

让我们尝试一下，你将少量盐投放到冰水里，温度降到了20度。

At this lower temperature, salty ice water can absorb more heat from the mixture inside the canister, freezing it faster than salt less ice water could.

在这种低温里，盐水能从金属罐里的混合物中吸收更多的热量，与淡冰水相比能尽快将其冻结。

This means you can quit cranking sooner, kick back on the porch and enjoy some good-old-fashioned ice cream.

这意味着你能快速停止摇动，返回走廊，享受美味的老式冰淇淋了。

1 maker   

n.制造者，制造商

参考例句：

• He is a trouble maker，You must be distant with him.他是个捣蛋鬼，你不要跟他在一起。
• A cabinet maker must be a master craftsman.家具木工必须是技艺高超的手艺人。

2 makers   

n.制造者，制造商（maker的复数形式）

参考例句：

• The makers of the product assured us that there had been no sacrifice of quality. 这一产品的制造商向我们保证说他们没有牺牲质量。
• The makers are about to launch out a new product. 制造商们马上要生产一种新产品。 来自《简明英汉词典》

3 texture   

n.(织物)质地；(材料)构造；结构；肌理

参考例句：

• We could feel the smooth texture of silk.我们能感觉出丝绸的光滑质地。
• Her skin has a fine texture.她的皮肤细腻。

4 crunch   

n.关键时刻；艰难局面；v.发出碎裂声

参考例句：

• If it comes to the crunch they'll support us.关键时刻他们是会支持我们的。
• People who crunch nuts at the movies can be very annoying.看电影时嘎吱作声地嚼干果的人会使人十分讨厌。

5 Fahrenheit   

n./adj.华氏温度；华氏温度计(的)

参考例句：

• He was asked for the boiling point of water in Fahrenheit.他被问到水的沸点是华氏多少度。
• The thermometer reads 80 degrees Fahrenheit.寒暑表指出华氏80度。