Reusing yesterday’s coffee grounds for another cup of coffee(wokelark.com)
wokelark.com
Reusing yesterday’s coffee grounds for another cup of coffee
https://wokelark.com/reusing-coffee-grounds-another-cup-of-coffee-caffeine-cold-brew/
118 comments
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)
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)
See too the “salami shot”[0] - illustrative of the phases that a single extraction goes through.
[0] https://youtu.be/_yIpi5KPUys
[0] https://youtu.be/_yIpi5KPUys
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.
> 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...
I would suggest reading How to make the best coffee at home, from James Hoffmann.
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...
I would suggest reading How to make the best coffee at home, from James Hoffmann.
> 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-extrac...
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-extrac...
I learned this when I tried making coffee using water from an RO unit. It was just kind of flat. I switched to filtered tap water and got better results. We get water from Lake Michigan which AFAIK has hardness about 135 ppm. I wish they had included Chicago it in the graph.
This 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/
>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/
From my experience, too much CaCO₃ is far worse than too little.
People sell mineral packets that you add to distilled water so you can control for this while brewing.
Both axes on the graph are "ppm CaCO₃", so why is it 2D?
The original paper where the graph comes from is not clear about it either. I think total hardness is calcium carbonate and magnesium ppm, but I am not sure.
Ew. 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.
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.
Buy 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
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.
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
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.
> 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).
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?
> 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).
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?
What reasoning do you have for avoiding plastic?
You're brewing coffee at <100°C, and all the plastic coffee brewers I've used have been BPA+BPS free (i.e. polypropylene)
Is there still any known issue? If they meant BPA, surely they could just say that?
Is there still any known issue? If they meant BPA, surely they could just say that?
Not sure about polypropylene, but both nylon and PET are known to shed billions of micro/nano-plastic particles into 95 °C water.
https://pubs.acs.org/doi/10.1021/acs.est.9b02540
Note they studied mesh bags. Flat surfaces with less exposed area should have lower emission rates. Still not great.
Edit: apparently polypropylene does too. https://www.theguardian.com/environment/2020/oct/19/bottle-f...
https://pubs.acs.org/doi/10.1021/acs.est.9b02540
Note they studied mesh bags. Flat surfaces with less exposed area should have lower emission rates. Still not great.
Edit: apparently polypropylene does too. https://www.theguardian.com/environment/2020/oct/19/bottle-f...
BPA is fine, but I'm more of a lead poisoning kind of guy.
Probably the leeching and your health
I confess that sometimes for a quick coffee I use the same espresso from the morning. I don't always feel like grinding beans, cleaning the portafilter, and tamping again. It's not great but not terrible.
Even if you go 10g over a normal shot, you're over-extracting which would start to taste bitter. But using already-extracted grinds for a new cup? I guess if you add lots of sugar and milk you may not notice.
I drink it black. Maybe I'm a masochist.
Masochists are the people adding sugar to things. There are lots of healthier options that taste almost the same if somebody craves sweetness.
> There are lots of healthier options that taste almost the same if somebody craves sweetness.
Alright. Don't hesitate to share then. I can't give away my one sugar... would love options to swap with.
Alright. Don't hesitate to share then. I can't give away my one sugar... would love options to swap with.
I’m all in on eritritol (my favourite) and stevia, but I’m also lucky that I don’t feel the difference. I know that some people do though.
Also just not eating sugar makes you more sensitive over the smaller amount of sugar food contains anyways.
Also just not eating sugar makes you more sensitive over the smaller amount of sugar food contains anyways.
Turn 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!
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!
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 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.
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.
> I am sorry, but I have to disagree.
You disagree that they enjoyed the article?
You disagree that they enjoyed the article?
So 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!
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!
Ask for a ristretto at your local good coffe shop/cafe or Italian restaurant.
https://en.m.wikipedia.org/wiki/Ristretto
Intensely flavourful IIRC.
https://en.m.wikipedia.org/wiki/Ristretto
Intensely flavourful IIRC.
That’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.
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.
For 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.
My batches of french press last 2 days, so in this way I suppose I am reusing the grounds.
Be careful! According to leading homeopaths, this could cause you to OD on caffeine.
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.
If you drink coffee for the hit, then it's pointless.
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.
Never underestimate the placebo effect
The placebo effect works because the user thinks it's genuine, no?
This 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
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://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.
More like pavlovian conditioning; the body gets the pre-caffeine signal (the taste of coffee) and gets to work.
this reads like generated blogspam
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.
Especially with the scroll-hijacking-in-line-ads every paragraph.
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.
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.
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.
FYI 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.
Considering how expensive and wasteful paper coffee filters can get, it's a nice optimization.
Personally I have a metal filter for my pour over. Less waste
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.
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.
I 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
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!
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!
What kind of stoichiometric alchemy converts time to volume?
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.
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.
This "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
[1] https://en.wikipedia.org/wiki/Nechezol
I 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.
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.
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.
I'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.
For 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.
And for as much as I like tea, coffee is irreplaceable.
Yeah 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.
There are companies of yesteryear that sold products like this to "reroast grounds".
https://www.youtube.com/watch?v=39g6utADRzs
They're awful.
https://www.youtube.com/watch?v=39g6utADRzs
They're awful.
This 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.
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.
What’s definitely possible is reusing green tea for a second or even third infusion.
In 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...
What happens if you use twice the amount of old coffee grounds to make cold brew? Would that approximate the original product?
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.
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.
> 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.
> 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.
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?
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?
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.
But I agree that it should be fine if you put it in the fridge.
If 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
Caffeine 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
cries in italian
Interesting, 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-caffei...
My BS alarm went off for this article but turns out its accurate: https://happyearthtea.com/blogs/tea-101-about-tea/can-caffei...
Chinese people 'wash' their tea like that before they drink it.
My 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.
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.
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On 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.
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.
I 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.
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.
This is addressed in the article. You are correct. She tries drying the spent grounds instead though.
Point taken. I tried not to tl;dr it but that article isn't very direct and to-the-point.
There'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.
Interesting 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.
Might be interesting to regrind french press grounds finer and change extraction methods.
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I 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.
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.
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.
James Hoffmann has a video on this topic https://www.youtube.com/watch?v=VV68NiRulEk
James Hoffmann has a video on this topic https://www.youtube.com/watch?v=VV68NiRulEk
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.
Imho 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.
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.
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.
Perhaps caramelising them before the second attempt could work. I very much doubt that they do not have more flavour to give.
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.
This fits my priors at least — reused beans generally aren’t great, but cold brew is pretty resilient to less-than-stellar beans.
I’ve heard this called “um carioca” in Portugal where they will pull a second shot from an already extracted espresso puck.
The 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.
> 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.
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I'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.
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.
Regarding alternate uses, caffeine is also a natural pesticide.
My God unblocked ads on mobile design are embarrassing.
Well I hope they got some good ad revenue
Haha at home we always make fun of cold brew as “monetizing cold coffee leftovers from yesterday” I guess this backs that up a bit :)
?
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).
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).
Cold brew is not "leftovers from yesterday."
>I guess this backs that up a bit :)
No it absolutely doesn't.
>I guess this backs that up a bit :)
No it absolutely doesn't.
If you made the coffee yesterday, that's the opposite of this.
And is all of this worth it? I personally don’t think so.
Betteridge's law of Headlines strikes again
Betteridge's law of Headlines strikes again
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TLDR: no because it tastes disgusting
MrMan(2)
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...