If 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.
Oof. 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.
Which 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.
Oh, 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.
I came to say the same thing. The 10th and 11th paragraphs (each one sentence) say the same thing. And they have the same effect as the title of the second section (immediately following those paragraphs). Each are the same idea of the article title.
I 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!
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.
Not 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.
They 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.
There 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.
Yeah 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.
Yeah, 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.
totally 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.
I'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.
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.
If 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.
> 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.
The 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.
From 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?
I 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.
I 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)
Are 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.
I 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.
A 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.
Yeah, not sure what the parent is talking about here... as long as you scrub decently or toss your metal filter in the dishwasher, fines won't be a big problem.
Would you mind sharing the model of metal filter that you use? I've been looking for a good one for my Chemex, but I haven't been able to find any decent comparison reviews. If yours has lasted 3 years that sounds like a buy to me!
Most coffee grinders have a large bean hopper on top that feed the grinding mechanism, and mine uses a power on timer that can be changed from 5-30 seconds.
The grinder processes beans at what seems to be a pretty constant beans/second flow rate, and through trial and error I figured out that "X beans/second * 12 seconds = Y volume of ground coffee" makes a cup of coffee that I like.
I've never bothered to figure out what "Y" actually equals, and the flow rate seems to stay constant enough that 12 seconds always works out to a good cup.
118 comments
[ 2.9 ms ] story [ 233 ms ] thread> I do not associate my blog with how the word “woke” is being used nowadays.
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).
>I guess this backs that up a bit :)
No it absolutely doesn't.
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.
You disagree that they enjoyed the article?
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.
James Hoffmann has a video on this topic https://www.youtube.com/watch?v=VV68NiRulEk
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.
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.
https://www.youtube.com/watch?v=39g6utADRzs
They're awful.
> 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.
But I agree that it should be fine if you put it in the fridge.
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?
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/
Sourced from: https://travisdanielbow.weebly.com/blog/category/cooking-exp...
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)
[0] https://youtu.be/_yIpi5KPUys
Betteridge's law of Headlines strikes again
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.
Considering how expensive and wasteful paper coffee filters can get, it's a nice optimization.
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.
Would you mind sharing the model of metal filter that you use? I've been looking for a good one for my Chemex, but I haven't been able to find any decent comparison reviews. If yours has lasted 3 years that sounds like a buy to me!
The grinder processes beans at what seems to be a pretty constant beans/second flow rate, and through trial and error I figured out that "X beans/second * 12 seconds = Y volume of ground coffee" makes a cup of coffee that I like.
I've never bothered to figure out what "Y" actually equals, and the flow rate seems to stay constant enough that 12 seconds always works out to a good cup.
[1] https://en.wikipedia.org/wiki/Nechezol
> 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.