这次先贴成品，猜猜看是什么？

这个既不是果汁也不是花生油，是最近实验 gelatin filtration 做出来的高汤。这方法早前曾看到默识先生推荐（参见这个链接 http://www.zhihu.com/question/22008541/answer/20020312），一直觉得好奇，于是前几天就在家一试。果然汤清味鲜，而且完全不需要技术，实为懒人下厨神技。

做法和原理上一段的链接已经提到，我只写点自己的体会好了。原材料方面，我用的是猪脚和鸡架（因为当天正好想吃猪脚），鸡鸭牛羊皆可。比较便宜的就是买鸡架，FairPrice 一盒两副一块多就可以，买上四五盒完全不成问题。熬汤无需讲究，焯水之后加姜葱酒水扔进电高压锅就可不管了。如果担心胶原蛋白不够，熬出来的汤里加点吉利丁就行。冷冻时用小的制冰格，结冰和解冻都会快些。解冻时我没用纱布，而是拿泡茶用的纸包，然后放进一个漏斗，下面直接流进瓶子里，如下图所示。

解冻时有一点需要注意，水快化完时需要注意不要让胶冻也化掉了，差不多就可以收工把胶冻扔掉了，不然就白做了（我自己就是白做了一回）。曾经想当然觉得放在冷藏里化冻就可以不用看，操作了一下发现和纯粹的冰块不同，融化得非常慢，不太实际。

以前看美食纪录片介绍开水白菜，讲吊汤如何繁复，如用这个办法，则人人可做开水白菜。科学的烹调技艺，能让懒人也做出好吃的菜来。

原始链接参见 http://en.wikipedia.org/wiki/Consomm%C3%A9#Gelatin-filtered_.22consomm.C3.A9.22

Freezing a water-based solution converts all bulk water into ice crystals, but water associated with solutes—in the case of a soup stock, gelatin, fat, and flavor compounds—remains unfrozen to much lower temperatures; in practice, the freezing temperature of this associated water is well below the reach of conventional freezers. Thus, gelatin filtration works by freezing a gelatin-containing, water-based solution and then allowing it to thaw in a mesh strainer at just above the freezing temperature of water. The gelatin and other solutes concentrate in the unfrozen, associated water, and the gelatin forms a stable network through cross-linking, just as it would in a standard gel. This stable network acts as a filter, trapping large particles of fat or protein, while allowing water and smaller, flavor-active compounds to pass. As the bulk water melts, it passes first through the gelatin network and then through the mesh strainer, into a receiving vessel. Because the temperature is kept just above the freezing point, the bulk water melts slowly and, as it is strained into a separate vessel, it is never in contact with the gelatin for long enough to begin dissolving the gelatin network. After all of the bulk water melts, the gelatin network remains in the strainer with the trapped macroscopic particles, and the clarified stock (the bulk water and flavor compounds) is collected in the receiving vessel.

至于健康与否，一般来讲肉汤固然鲜美，营养价值却不高。即便你熬汤熬到肉烂骨酥，绝大多数营养物质还是在肉里的。