其他2016ncbi.nlm.nih.gov
被忽视的食物气泡：意式浓缩咖啡泡沫
Neglected Food Bubbles: The Espresso Coffee Foam
进阶 · 约 30 分钟读完前置知识：食品科学基础、胶体与泡沫、意式浓缩咖啡萃取
导读
这篇论文聚焦意式浓缩咖啡表面的泡沫（crema），把它作为一类“被忽视的食品泡沫”来讨论，从食品科学角度审视其形成与特性。作者之一是被誉为咖啡产业研究推动者的 Ernesto Illy。
HN 关注点：HN 读者既关心浓缩咖啡萃取背后的科学，也对 crema 与豆子新鲜度、研磨等实操变量的关系很感兴趣。
HN 评论精选
这几条评论里：支持 1 补充 1 亲历 2
补充指出论文作者与 Illy 咖啡公司的渊源。
作者之一是 Ernesto Illy——对，就是那个 Illy。他在本文发表几年前去世，但曾领导公司开展多项持续数十年的应用研究项目。
matthewmcg查看英文原文
One of the authors is Ernesto Illy--yes that Illy[1]. He passed away a few years before this article was published but led the company's various multi-decade applied research projects. [1]: https://en.m.wikipedia.org/wiki/Ernesto_Illy
亲历亲历说明设备、新鲜豆子和陈豆调细研磨对 crema 的影响。
我第一台做浓缩的机器是浓缩/滴滤二合一。当时不懂，只是做出浓咖啡而非真正的 espresso。后来买了独立浓缩机，更接近真货，但仍远不如 Temple Coffee 这类烘焙店做的。最后我投入 Breville BES870XL，经过大量试错，做出的浓缩已和烘焙店专业人员做的几乎难以区分。对我而言，从 Temple、Verve 或 Ritual（萨克拉门托/旧金山地区）这类烘焙店买豆子，对味道和 crema 影响巨大。crema 的量肯定和空气暴露有关，所以豆子越快用完越好（接触空气后两周内左右）。另外我的经验是，豆子放很久、超过两周后，研磨要调细一档；因为原设置下萃取在低得多的压力阈值就开始了，导致萃取不足、浓缩淡薄且几乎没有 crema。很想有人研究豆子变陈后需要磨细以保持一致性这一具体问题。
HoppedUpMenace查看英文原文
My first machine to make espresso was a espresso/drip coffee combo. Not knowing any better, I was merely pulling strong coffee and not espresso shots. Then I got a stand alone espresso machine, much closer to the real deal but still a far cry from what a coffee roaster like Temple Coffee could make in their store. Finally, invested in a Breville BES870XL and after many trials and errors, my espresso shots are fairly indistinguishable from what the pros at the coffee roasting shops make. Getting the beans from a roasting store like Temple or Verve or Ritual (Sac/San Fran area) makes all the difference in the world for taste and crema IMO. The amount of crema is definitely tied to air exposure so the quicker you can use up your beans the better (under 2 weeks or so from exposure to air). Additionally, its been my experience that I have to adjust the grind setting to 1 step finer if the beans have been sitting for a very long time, past the 2 week mark or so. I do this because at original setting, the extraction begins at a much lower pressure threshold than usual, leading to under-extraction and weak, watered-down espresso with little to no crema. It'd be nice to know if anyone has studied this particular aspect of coffee beans needing to be ground finer to compensate for age to maintain consistency.
支持强调浓缩咖啡是过程与原料共同作用，量化技艺很有价值。
浓缩咖啡是种了不起的混合物。crema、香气和味道既来自过程（压力、温度、时间、粉量），也来自原料（豆子、烘焙、新鲜度）。所有因素必须在同一时间以正确方式配合，容错空间很小，否则得到的只是一杯苦涩热水。稳定做出合格的浓缩需要大量练习，我很高兴有人尝试量化熟练咖啡师的那种“魔法”。
crispyambulance查看英文原文
Espresso is a remarkable concoction. The crema, aroma, and taste is as much a product of the process (pressure, temperature, time, and dose) as it is the raw ingredients (the beans, roasting, freshness). Everything has to come together at the same time and in the right way with little room for error, otherwise you end up with bitter hot liquid. Pulling a righteous shot of espresso takes a serious amount of practice and I am glad that there are attempts at quantifying the magic of a skilled barista.
亲历分享用手动设备和工具控制变量、追求虎斑 crema 的实践。
我一直喜欢浓缩，也确实很难做出好的一杯。为了解其机械原理，我买了手动 EspressoForge。配合好的手摇磨（Lido 2）、温度计、秤和压力表，就能手动控制主要变量。学习曲线很陡，但一旦掌握，平衡所有变量并看到完美的虎斑 crema 流出，会非常有成就感。我会好好研读这篇文章。
nathancahill查看英文原文
I've always loved espresso, and it is indeed difficult to pull a great shot. To learn more about the mechanics of it, I got a manual EspressoForge[0]. Combined with a good manual grinder (Lido 2), a thermometer, a scale, and a pressure gauge, you can control the main variables* by hand. Steep learning curve, but once you get it, there's something immensely satisfying about balancing all the variables and seeing that perfect tiger-stripe crema pour out. I'll be studying this article for a while. * I also roast my coffee beans, but a trusted coffee roaster will work too. [0] http://espressoforge.com/
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