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Reusing yesterday’s coffee grounds for another cup of coffee
- kotaKat 4y agoThere are companies of yesteryear that sold products like this to "reroast grounds". https://www.youtube.com/watch?v=39g6utADRzs https://www.youtube.com/watch?v=39g6utADRzs They're awful.
- bee_rider 4y agoThis fits my priors at least — reused beans generally aren’t great, but cold brew is pretty resilient to less-than-stellar beans.
- cf100clunk 4y agoIf the coffee grounds were left at room temperature in the basket or device since the previous brew, wouldn't they be home to bacteria and maybe other unpleasantness? I'm guessing immediate cold storage of the used grounds would be necessary. I'll stick to fresh, on-demand grinding.
- yellow_lead 4y agoThis is addressed in the article. You are correct. She tries drying the spent grounds instead though.
- cf100clunk 4y agoPoint taken. I tried not to tl;dr it but that article isn't very direct and to-the-point.
- lzooz 4y agoI'll have this printed for when I become a bum
- aliqot 4y agoCharmin is cheaper
- dgacmu 4y agoOof. This article is horribly painful to read. Tl;dr: it's exactly what you'd expect. Weak and not as tasty. Cold brewing it might work best. Less than half the caffeine of the first extraction. Don't let wet coffee grounds stay in the counter overnight to gather mold and bacteria before reusing.
- ruined 4y agothis reads like generated blogspam
- Our_Benefactors 4y agoEspecially with the scroll-hijacking-in-line-ads every paragraph.
- cauliflower2718 4y agoWhich ads? The links I see are either to her other blog posts or to scientific studies. For example, the "cold brew method", "French press", "better water for coffee making", and "pressurized portafilter basket" links are all tutorial or explainer blog posts.
- jrmg 4y agoOh, man, I’m glad I’m not the only one to think this. It felt like a real article was in there, but the author had copied the stilted, overly verbose style of generated-for-SEO articles. I really hope we’re not entering a world where quality content has to be written in this robotic, repetitive way to ‘work’ online.
- deleted 4y ago[deleted]
- MrMan 4y ago[flagged]
- loloquwowndueo 4y agoHaha at home we always make fun of cold brew as “monetizing cold coffee leftovers from yesterday” I guess this backs that up a bit :)
- kortilla 4y ago? Cold brew is not just refrigerated coffee. That would be “iced coffee”. Cold brew is made in the fridge with new grounds (no hot water involved).
- Dylan16807 4y agoIf you made the coffee yesterday, that's the opposite of this.
- astura 4y agoCold brew is not "leftovers from yesterday." >I guess this backs that up a bit :) No it absolutely doesn't.
- cardamomo 4y agoI generally concur with sibling commenters' criticisms, but I still enjoyed reading this article. To me it's a light-hearted but nevertheless thorough exploration of coffee brewing. I love that the author attempts to answer a question that almost nobody was asking—simply out of sheer curiosity!
- deepspace 4y ago> I still enjoyed reading this article I am sorry, but I have to disagree. The stilted, repetitive, one sentence per paragraph style is so obtrusive and so reminiscent of blog spam that I could not focus on the content. At the end of the day, all the author does is re-brew a cup of coffee with used grounds. Who has not tried that at least once (and went blegh and never tried it again)? To me, the article is as content-free as it is hard to read.
- NoahTheDuke 4y ago> I am sorry, but I have to disagree. You disagree that they enjoyed the article?
- deleted 4y ago[deleted]
- hardwaregeek 4y agoNot coffee, but I've wondered this about stock. Recipe authors claim that the vegetables/meat have no more flavor to give, but I don't know if they've actually tested this.
- PartiallyTyped 4y agoPerhaps caramelising them before the second attempt could work. I very much doubt that they do not have more flavour to give.
- wirrbel 4y agoImho if they had more flavour to give my grandmother would have increased the water-to-bone ratio in her personal recipe book. That being said the veggies are often fairly tasty. The hat is they won’t nurture a next gallon of broth but without further dilution they are great.
- OJFord 4y agoThey certainly do - blend the stock pot and you've got a soup that tastes different to the stock - but you might not extract much by further boiling if you were already patient with the stock.
- kibibyte 4y agoThere is actually a substantial amount of flavor left, but just like in coffee, it's very difficult to extract without increasing the surface area of the vegetables and meat you add in. And how can you increase the surface area? Exactly the way you'd expect to. James Hoffmann has a video on this topic https://www.youtube.com/watch?v=VV68NiRulEk https://www.youtube.com/watch?v=VV68NiRulEk
- hardwaregeek 4y agoYeah I blend my ingredients sometimes. It produces a very intense stock which is not always what I want, but it is quite good. Recently I tried blending and then browning the blended result. It worked decently well.
- tdeck 4y agoWhat happens if you use twice the amount of old coffee grounds to make cold brew? Would that approximate the original product?
- ryanwhitney 4y agoYeah, that’s what’s missing here: experimentation on how to make it work. I’ve tried this by re-using grounds, but also adding fresh grounds on top. (About half as much as i’d normally use.) It still comes out a bit watery, but much closer to normal.
- momirlan 4y agototally agree with grandma : nothing wrong with a second, decaf brew. my grandma, in the old times, used the burned crust from the home made bread for the morning coffee. peasants could not afford real coffee. it was similar to chicory coffee, not too bad.
- HKH2 4y agoIf you drink coffee for the hit, then it's pointless.
- zdragnar 4y agoI'll occasionally brew a cup of decaf or half-caf if I'm looking for a small perk in the evening but don't want to risk being up too late. Possibly an addiction thing (pavlov's bitter brew?) or possibly just the nature of the bitter flavor.
- kQq9oHeAz6wLLS 4y agoNever underestimate the placebo effect
- HKH2 4y agoThe placebo effect works because the user thinks it's genuine, no?
- HourglassFR 4y agoThis can only be a patial explanation of the effect since it is known to occur even when the patient is informed that the substance is inactive. https://en.m.wikipedia.org/wiki/Placebo#Mechanisms https://en.m.wikipedia.org/wiki/Placebo#Mechanisms Maybe there is something akin to belief in the belief, i.e. "I'm not religious but will pray for god or whomever in dire situations". The mind is a weird thing and truth is, we don't have a good understanting of what's going on with the placebo effect.
- xsmasher 4y ago
- markiannucci 4y agoIn 2015, I had a similar curiosity. Coffee stack exchange was just getting started and the top answer is enlightening. https://coffee.stackexchange.com/questions/1749/brewing-with-the-same-coffee-grounds-twice https://coffee.stackexchange.com/questions/1749/brewing-with...
- cypress66 4y agoIf you've ever done a salami shot, it will be obvious that reusing grounds like this will never work, at least assuming you want your coffee to taste any good.
- dehrmann 4y agoMight be interesting to regrind french press grounds finer and change extraction methods.
- Scoundreller 4y ago> When reusing coffee grounds to make another coffee the next day you risk ingesting unwanted fungi and bacteria. > These are attracted by the wet grounds and it’s possible that the microorganisms start establishing their colonies in less than 24 hours. > Therefore drinking coffee that’s made from yesterday’s grounds could be potentially dangerous while also having an unpleasant taste. Storing the spent grounds in the fridge would be a good preservation method. Personally, I think putting boiling water in the grounds as an initial treatment should kill off any initial bacteria. Fungal spores aren’t killed by boiling, but they might germinate after soaking and then get killed after the second hit. This was an early method of killing fungal spores before pressure vessels: tyndallisation. Coffee grounds (without any sugar, etc.) isn’t a very nutritive media.
- antognini 4y agoThe second boil wouldn't really help much with the food safety. The bacteria or fungi aren't themselves toxic, it's the waste they produce that is. And unfortunately those toxins aren't destroyed by boiling water. But I agree that it should be fine if you put it in the fridge.
- stephen_g 4y agoFrom experience, when it’s a bit humid here the pucks out of my espresso machine start growing visible mould in my knock box extremely quickly. Sure, refrigerating them and keeping them in an airtight container would slow that but why risk it when all the good flavours of the coffee are already extracted?
- pessimizer 4y agoI love this, and even though it seems like the experiments were a failure, if one hadn't been it might have saved a lot of people a lot of money. As it is, it's saved at least a few people from trying the experiment themselves. Also there's a list of alternative uses for coffee grounds, and a link to another blogpost that expands on those in detail. This post took more effort than 99% of blogposts, calling it blogspam is pretty offensive. It reminds me of another favorite article online: https://www.instructables.com/The-Science-of-Biscuits/ https://www.instructables.com/The-Science-of-Biscuits/ Sourced from: https://travisdanielbow.weebly.com/blog/category/cooking-experiments https://travisdanielbow.weebly.com/blog/category/cooking-exp...
- Gigachad 4y agoI think it’s a pretty easy and informative experiment to take espresso two shots from one puck in to two cups. I did this recently, the first shot was a beautiful, almost thick, sweet and sour coffee. The second one was like burnt dirt water. Turns out the espresso machine is already set up to stop extracting just at the point where all the good flavours have been removed. (Also reason to be thankful that the good flavours happen to extract first)
- bch 4y agoSee too the “salami shot”[0] - illustrative of the phases that a single extraction goes through. [0] https://youtu.be/_yIpi5KPUys https://youtu.be/_yIpi5KPUys
- 2muchcoffeeman 4y agoAre well designed experiments actually failures? You set out to find out something: “can I extract sufficient caffeine from spent coffee grounds?” The person found out the answer. Sounds like a success.
- ramesh31 4y agoI do it every day. First pot in the morning is fresh, and my “2:00 pot” uses the same grounds. It’s weaker, but that’s the point.
- anigbrowl 4y agoAnd is all of this worth it? I personally don’t think so. Betteridge's law of Headlines strikes again
- baxtr 4y agoWhat’s definitely possible is reusing green tea for a second or even third infusion.
- angry_moose 4y agoI use a Chemex drip coffee maker and get pretty good results by halving the amount of grounds I use for subsequent cups. No idea about the caffeine content but the taste is not noticeably different. With my grinder, a 12 second grind gives a good first cup. For the second cup I keep the spent grounds in the filter and add another 6 second grind. If I go for 3, another 6 second grind. That works out to a 25% or 33% savings depending on number of cups (18/24 seconds vs 24/36). I've never tried carrying them over day to day.
- vanilla_nut 4y agoFYI you can wash and reuse Chemex paper filters 2-5 times, in my experience, before they start to taste weird or fall apart. Considering how expensive and wasteful paper coffee filters can get, it's a nice optimization.
- feet 4y agoPersonally I have a metal filter for my pour over. Less waste
- 2muchcoffeeman 4y agoA decent metal filter that is really catching all the fines doesn’t last long. It will soon be clogged with fines. If you want to minimise waste, get an aeropress. Stick with the paper filters and use a soft clean toothbrush to clean the filter. You’ll notice that if you use the aeropress as a pour over, the draw down rate will stay consistently fast. The filters are much smaller and are good for at least 5 uses.
- feet 4y agoI just clean the filter regularly, it does drain a bit slow after a couple uses between thorough washes but it's still going strong after 3+ years
- 4y ago
- netfortius 4y agoThis "research" reminded me of the nechezol [1] we enjoyed under the guidance of the renown coffee specialist Ceaușescu [1] https://en.wikipedia.org/wiki/Nechezol https://en.wikipedia.org/wiki/Nechezol
- gumby 4y agoThe TL;DR is: > And is all of this worth it? I personally don’t think so. Author put some thought into it so it’s an interesting read, but still, the lede should not have been buried.
- crazygringo 4y agoSo the answers are about what you'd expect -- it's weak, cold brew is better but still weak, and who even knows if there's any caffeine in there. But I still can't help but wonder out of sheer curiosity, to take this to the limit -- what about making cold brew but with 3x or even 5x or 10x the normal ratio of grounds to water? Surely there's a way to get "reused" coffee to a comparable concentration to "first use". And then... would it be even remotely drinkable, or too much bitterness-to-flavor? Sufficiently caffeinated, or would comparable caffeine make it unbearably bitter? I'm so curious now -- I feel like this blog post got 80% of the way, but is missing the final experiment!
- moistly 4y agoAsk for a ristretto at your local good coffe shop/cafe or Italian restaurant. https://en.m.wikipedia.org/wiki/Ristretto https://en.m.wikipedia.org/wiki/Ristretto Intensely flavourful IIRC.
- 2muchcoffeeman 4y agoThat’s not the same as overdosing a cold brew. Once heated the coffee will go stale and reheating won’t lead to good results. The parent is on the right track if they want to get a strong and storable coffee. Overdose a cold brew, and dilute (or not) and microwave for a hot drink.
- sigil_my_ev 4y agoTurn it into compost or leave a bucket of grounds outside long enough and you'll end up with a hearty colony of black soldier fly larvae that will consume up to 5lbs of grounds and organic matter per day. BSF are fascinating, they prevent deadly pathogens reduce the volume of organic waste quickly and actually produce insect frass more nutrient dense than worm castings. Amazing little creatures!
- arealaccount 4y agoInteresting, I’ve always understood you can decaffeinate tea by doing a thirty second steep, discarding, then steeping again for however long the tea requires. My BS alarm went off for this article but turns out its accurate: https://happyearthtea.com/blogs/tea-101-about-tea/can-caffeine-be-rinsed-from-tea https://happyearthtea.com/blogs/tea-101-about-tea/can-caffei...
- HKH2 4y agoChinese people 'wash' their tea like that before they drink it.
- pcthrowaway 4y agoIf I were going to try this, I'd probably start with a coarse grind in a french press for the first brew, then immediately dry the beans in a food dehydrator, regrind to espresso grind, and try the second brew in the aeropress
- deleted 4y ago[deleted]
- qbasic_forever 4y agoI've been on a kick drinking black tea in the morning before I have coffee. Tea is a lot cheaper than coffee and I find a cup of it before coffee kind of primes my taste buds so the coffee tastes even more amazing.
- slothtrop 4y agoFor grocery-store commodity tea I agree. I find loose leaf teas can very quickly get more expensive than your average boutique coffee roast. Personally I usually just get Yorkshire Gold or something, which is not that expensive. I'm interested in trying more loose leaf varieties (particularly Japanese and Chinese) but I'm too cheap right now. And for as much as I like tea, coffee is irreplaceable.
- qbasic_forever 4y agoYeah I actually found 100 tea bag packs of black tea at the dollar store of all places--not bad for $1.25! The bags are super cheap and junky but it doesn't matter, the tea brews up just fine. Loose leaf stuff is great for afternoon or when I want tea as more of a treat.
- ademup 4y agoFor me, coffee tastes far superior when it is much more diluted than "normal". 1 liter French press with 2 tablespoons of grounds. Then put about 2 tablespoons of this liquid with 32 oz of ice water. It should now look like light tea. It's a refreshing beverage I can drink from 8am to 2pm with no downsides. This drink can be replicated at starbucks as "can I get a shot ... And a venti ice water with light ice". Then combine. Side benefit is they often charge much less than an Americano. My batches of french press last 2 days, so in this way I suppose I am reusing the grounds.
- shalmanese 4y agoBe careful! According to leading homeopaths, this could cause you to OD on caffeine.
- gchamonlive 4y ago> If you get all of those variables right, you will end up with the best, well-balanced cup of coffee in your hands. Those variables were: - coffee/water ratio - grind size and consistency - water temperature - extraction duration But there is a fifth element that should be observed that is the water hardness. Having too much or too little magnesium and calcium disolved in the water may result in wildly different cups of coffee. Yes, that is leaning more towards the pedantic side, but if you live in a region with extremely soft water, you have to fix water hardness because it is essential to dissolving coffee compounds in it. Water hardness graph: https://jgagneastro.files.wordpress.com/2018/12/water_coffee_chart-1.png?w=1600 https://jgagneastro.files.wordpress.com/2018/12/water_coffee... I would suggest reading How to make the best coffee at home, from James Hoffmann.
- bigDinosaur 4y agoFrom my experience, too much CaCO₃ is far worse than too little.
- naet 4y agoThis is covered in the article right after where you quoted. >Furthermore, the type of water you use also plays a vital role in the process of coffee extraction. >You can learn more about the best water for coffee making, by clicking here. https://wokelark.com/best-water-for-coffee/ https://wokelark.com/best-water-for-coffee/
- user3939382 4y agoPeople sell mineral packets that you add to distilled water so you can control for this while brewing.
- rav 4y ago> Water hardness graph: Interesting graph, but I was missing some explanation. Here's the figure text, from [1]: "Water properties for various recipes, cities and bottles. The dashed line represents a 1:1 relation, and color lines correspond to different recommended ranges. In the figure above, you can see the range recommended by the SCA (green bar), the region recommended by the Colonna-Dashwood & Hendon (2015) Water for Coffee book (this mythical book is now pretty much impossible to find, but it is said by the ancient ones to go much deeper in the chemistry of coffee extraction than what I could ever write in this blog post), and the more constrained region recommended by the Specialty Coffee Association of Europe (SCAE), which is mainly based on avoiding regions of significant scaling (upper right) or corrosion (upper left), two aspects that are mostly important to the delicate internal parts of espresso machines." [1]: https://coffeeadastra.com/2018/12/16/water-for-coffee-extraction/ https://coffeeadastra.com/2018/12/16/water-for-coffee-extrac...
- bumpkinjunkie 4y agoI’ve heard this called “um carioca” in Portugal where they will pull a second shot from an already extracted espresso puck.
- rockzom 4y agoMy God unblocked ads on mobile design are embarrassing.
- bioemerl 4y agoCaffeine is way more soluble in water than most of the other stuff, so you get most of the caffeine out of the coffee when you brew it the first time, the second cup will be much less potent
- pleb_nz 4y agoI've been second brewing plunger coffee for a while now and it's well worth the effort if you don't mind the diminishing potentency and flavour. For me the diminishing potency is perfect as I don't want full strength coffee after 9 or 10 am so it's 0erfect and it saves me a bunch of coin.
- cpfohl 4y agoEw. Glad the article ended on a no. Coffee at home is not expensive enough to justify such madness. A pound of coffee makes about 7 8 "cup" (5oz) pots. I tend to get 4.5 mugs of coffee out of an 8 cup pot. Even overpriced Starbucks at $10/12oz (~$13/lb) means that each mug of coffee is still only costing me around $0.35. I'll brew with fresh grounds, thanks. You can _always_ add water if you want warm brown caffeinated water.
- RajT88 4y agoBuy cheap grounds in the biggest quantities you can store. I actually prefer Cafe Bustelo from local latino supermarkets (which is inexpensive, but not "cheap", it's really good!). Buy a coffee maker where no hot water touches plastic. Just glass and steel. You will find that this gets you most of the way to great coffee. I had this guy, and it lasted about 5 years. But you can do DIY pourover with similar results, electric or stovetop tea kettle + carafe with pourover: https://www.amazon.com/gp/product/B076VVTRNM https://www.amazon.com/gp/product/B076VVTRNM Keep it simple, and good coffee is cheap. No need to re-use grounds. I do have one use case for grounds re-use: If I want something hot to drink in the afternoon. I have good tolerance for caffeine (I have never become physically dependent), but I just have to keep caffeine consumption to before 3pm, or I might have a hard time sleeping. A re-run of the morning's grounds (usually 3 scoops of grounds), gives me coffee flavor, but without too much caffeine.
- TheDong 4y ago> Buy cheap grounds in the biggest quantities you can store > Buy a coffee maker where no hot water touches plastic. Just glass and steel. > ... gets you most of the way to great coffee. James Hoffman, who's credentials include winning the "World Barista Championship", publishing multiple coffee books, running a coffee roasting company, and so on, has significantly different advice. When experimentally comparing the glass, plastic, and ceramic V60s, he found that the plastic was easier to preheat and sucked less heat out of the grounds, resulting in better brews (https://youtu.be/1oB1oDrDkHM?t=480 https://youtu.be/1oB1oDrDkHM?t=480). What reasoning do you have for avoiding plastic? How can it change the brew other than through its thermal properties (which are pretty clearly beneficial compared to glass and steel, right?) He also recommends getting grinding beans very shortly before brewing. I personally can easily taste the difference between freshly ground and stale grinds, and can notice the difference in extraction and flavor from varying grind size, so I'm personally quite dubious of your claims. I have yet to ever make "great coffee" from pre-ground beans bought from the super-market, only mediocre coffee. Can you not taste any different between fresh grinds and pre-ground coffee? From fiddling with the grind size to find the right extraction for what you personally prefer?
- causi 4y agoThere's definitely some value in leftover grounds, in that if you're stuck with no coffee and no ability to get coffee, shaking up that used pod and running it again will result in something drinkable containing caffeine, if not something tasty.
- Pxtl 4y agoOn the subject of syrup and sugar in cold-brew in the article: Simple syrup is incredibly easy to make and dissolves readily in cold coffee. I often make myself a small afternoon iced coffee from my leftover morning carafe, and a bottle of simple I made for cocktails is handy for that. 2 parts sugar to one part water, heat the water until the sugar is dissolved then bottle it.
- deleted 4y ago[deleted]
- unrealp 4y agoRegarding alternate uses, caffeine is also a natural pesticide.
- brailsafe 4y agoWell I hope they got some good ad revenue
- kibibyte 4y agoI appreciate the author running these experiments; even though I think the answers were obvious, it does confirm a lot of what we know about coffee extraction. I do have a few related thoughts on some different points in the article. > The ideal extraction yield for coffee is between 18% and 22%. An under-extraction of 15% or over-extraction of 25% will cause an imbalance in the components and will result in either acidic or a bitter-sweet coffee drink. The lower bound of the range is accurate, but the upper bound is outdated. People like Scott Rao and the folks at Barista Hustle have been involved in expereriments to push extractions even higher than that; if I recall correctly, I think they've reached just shy of 30% while improving the taste of the resulting coffee. The key is that bitter flavors don't simply start extracting past 22%, but that above 22%, the _evenness_ of extraction becomes very important. This is the point where factors like the grind size distribution (from the specific combination of beans, grinder machine, and burrs) and technique (e.g. your method of hand pouring to avoid fine particles from clogging the filter) really start to matter. Bitterness can even occur at 18% extraction if the grind size distribution is very uneven. Another related detail the author mentions is that the second and third re-brews result in more watery cups. This is partly because fines (the tiniest particles) in suspension are major contributors to the texture of the coffee beverage, especially for espresso. Once you've extracted most of them in the first brew, there won't be much left for repeated brews. My angle on this is that this is not a useful technique unless you're intentionally trying to ration coffee. If your repeated brews seem to extract some additional good flavor, you may want to explore ways to increase the extraction from the first brew instead. On a related note, there is an old invention that essentially constantly rebrews coffee: the percolator.
- atoav 4y agoThis is a valid technique if you do cold extraction (e.g. cold brew). I often reuse coffee grounds and mix them with fresh coffee when cold brewing with no particular downsides. Cold brewed coffee also lasts much longer before going into "tastes like old coffee"-territory, you can have it in the fridge for weeks while hot brewed coffee can taste bad after a few hours already. It is said that the acids in the bean play a role in this, and those acids are not extracted during cold brewing. There is people experimenting with ultrasonic extraction processes as well.
- napolux 4y agocries in italian
- kybernetyk 4y agoTLDR: no because it tastes disgusting
- aaron695 4y ago
- Broken_Hippo 4y agoMy parents used to do a version of this when I was a child. They'd make coffee, add a little coffee on top (about a quarter of the amount normally used), and then brew that mixture of grounds. This was done in a drop machine: I can't remember if they did this with the percolator. They stopped when they had enough money to use fresh grounds daily. If it wasn't inferior, I'm not sure they would have stopped.
- Overtonwindow 4y agoI can not personally-easily taste the difference between freshly ground and stale grinds. Difference in extraction and flavor from varying grind size has merit but dubious of your claims.
- eurasiantiger 4y agoInteresting that they would use such a subjective measurement as how much a cup of coffee ”wakes you up”. If only we could discuss other central-nervous-system-stimulating, habit-forming, impulsivity-increasing pharmaca so casually.