其他2022nature.com
皮秒脉冲激光萃取冷萃咖啡
Cold-brewing of coffee by picosecond-pulsed laser extraction
入门 · 约 30 分钟读完前置知识：咖啡萃取基础、激光与空化的基本概念
导读
这篇论文研究用皮秒脉冲激光从咖啡粉中提取风味物质，实现无需加热的快速'冷萃'咖啡。激光诱导的空化/机械作用可在极短时间内完成萃取，同时避免传统热萃带来的高酸度和苦味。
HN 关注点：HN 读者对咖啡萃取技术与'用激光做咖啡'这种看似荒诞却真实发表的研究感兴趣，讨论焦点是冷萃的必要性、替代方案和能否在家复现。
HN 评论精选
这几条评论里：质疑 2 补充 1 亲历 1
亲历推荐一款基于声空化的商用快速冷萃设备 Osma，分享日常使用体验和价格
去年我众筹支持了一个叫 Osma 的项目（drinkosma.com），它利用声空化在不加热的情况下约一分钟内萃取出咖啡的风味和咖啡因。我每天都在用，很喜欢。我爱冷萃的浓郁风味，胃也感激它的低酸度。虽然需要摸索调参，但对 HN 读者来说这种实验过程是乐趣而非负担。当时买得便宜，现在整套售价 695 美元。注意和所有咖啡器具一样，效果取决于你的磨豆机，我给它配了 Baratza Sette 270。
peteforde查看英文原文
Last year I backed a project called Osma. https://drinkosma.com/ It uses acoustic cavitation to extract flavor and caffeine from coffee without any heating in about one minute. I use it every day and I like it. I love the strong flavor of cold brew, and my stomach appreciates the lack of acidity. There is a learning curve but if you're a HN reader, chances are the amount of experimentation required to dial in your version of perfection is an upside, not a downside. I paid less at the time, but today the kit is selling for US$695. Note that as with all things coffee, it's only as good as your grinder. I ended up pairing my Osma with a Sette 270: https://baratza.com/grinder/sette-270wi/
质疑质疑冷萃被过度神秘化，其实自己在家做非常简单
我一直很困惑冷萃咖啡怎么会被搞得像什么神秘又难以获得的 concoction。把磨好的咖啡装进滤袋，放进冰箱的冷水里，第二天回来喝就行了，想泡多久泡多久。
pushedx查看英文原文
I’m constantly baffled by cold brew coffee seeming like a mysterious and arduously-obtained concoction. Stick ground coffee in some filter bags and put it in some cold water in the fridge. Come back the next day and drink it. Leave it in there however long you want.
质疑质疑'酸度'一词的歧义，并追问皮秒激光的必要性与家用可行性
我从没喝过冷萃。文章说冷萃'酸度和苦味更低'。我喜欢带果味和柑橘调的咖啡，据说咖啡行家把这种果味称为'酸度'。那冷萃是不是果味更淡？作者把'酸度'理解为 pH，这比'果味'好测，但醋的味道显然不'果'。另外为什么非得用皮秒激光？说纳秒脉冲太长会发热——得多热才算问题，直接冷却容器不行吗？在家能搭这套装置吗？需要多大功率、什么波长？一百美元以下的皮秒激光器（去痣/洗纹身用的）能用吗？
denton-scratch查看英文原文
I've never drunk cold-brewed coffee. According to the article, cold-brew has "less acidity and bitterness". I happen to like coffee with fruit and citrus tones. I'm not a coffee bore, but I have understood that coffee bores refer to that fruitiness as "acidity". Does that mean that cold-brew would be less fruity? The authors take "acidity" to mean "pH", which is obviously easier to measure than "fruitiness", but I wouldn't describe the taste of e.g. spirit vinegar as "fruity". Supplementary question: why's it got to be a picosecond laser? They say that a nanosecond laser's pulses are too long, and cause heating. How hot does it have to get for that to be a problem? Can't you just cool the brewing vessel? Supplementary supplementary: can apparatus for doing this be built at home? How much ps-laser power needs to be delivered to the brew? At what wavelength? You can get handheld picosecond lasers for things like mole and tattoo removal, for under $100; would one of those do the trick?
补充调侃研究来源，并分享一个利用类似物理过程的趣闻
哈，这篇文章听起来像一群爱咖啡的物理研究生在拖延毕业论文，教授说：嗯，也许这能发表！当年曼妥思+健怡可乐火的时候，我一位经营生物技术公司（总在写经费申请）的朋友，就提交过一份基于类似原理的气溶胶化提案，作为军用大规模分散系统，不知道最后有没有拿到经费。
prewett查看英文原文
Ha, this article sounds like some coffee-loving physics grad students procrastinating on their thesis, and their professor said, hmm, maybe we can publish this! When the Mentos + Diet Coke thing was first a big thing, a friend of mine who ran a biotech firm (so was always writing funding proposals), submitted a proposal for an aerosolizer using a similar process, as a mass dispersal system for the military, if I recall correctly. Don’t know if it ever got funded, though.
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