I don't get why this is significant. How is this a better substrate than any other flexible plastic? Isn't the issue with flexible electronics the robustness of the circuits and components?
Article was paywalled for me, but in general Plastic does not decay so for products that are essentially consumables it's better if it doesn't stay and pollute the environment.
No, it's a good point and I'd like to know as well.
Ofc being biodegradable means it will sooner find it's way into some photosynthesis and recapture that carbon.
Are greenhouse emissions lower when fermenting some sweet tea, versus extracting oil from the earth, refining it, converting that into plastic, then forming that plastic into the shape you want?
SCOBY is basically a waste product from producing kombucha, you have to remove an amount from each batch which (in the case of home brewing) is usually given away to others for free or discarded, not sure how they handle it with industrial-scale kombucha making. So this could be more of a clever recycling that doesn't produce any more CO2 than was already being produced during the making of kombucha.
This is true if you make naive assumptions like making circuit boards are a clean technology with no CO2 emissions or other harmful side effects. That of course is entirely incorrect. Printing circuit boards are very energy intensive along with a lot of other impacts like toxic waste and heavy water use.
> In the US, a single fab, Intel’s 700-acre campus in Ocotillo, Arizona, produced nearly 15,000 tons of waste in the first three months of this year, about 60% of it hazardous. It also consumed 927m gallons of fresh water, enough to fill about 1,400 Olympic swimming pools, and used 561m kilowatt-hours of energy. (source https://www.theguardian.com/environment/2021/sep/18/semicond...)
Kombucha on the other hand, yes produces CO2 as a waste product, but it is very easy to see a kombucha SCOBY being carbon neutral. That is the source of it's sugars being carbon energy free, and the manufacturing process of SCOBY circuits as well. Then it's carbon neutral
Environmentally speaking, it's better, since it's biodegradable.
On the other hand, buying a gadget that dissolves when it gets just a bit wet might not be a smart thing...
But i can totally see them selling "biodegradable" flashing LED bracelets (or similar single-use crap), where the bracelet iself is biodegradable, and the rechargable battery (without an actual charging circuit) and plastic potted LEDs are not....
I've held it, but i've also got it wet (after being dry), and i seriously doubt that the printed-on metalic layer would survive, since the surface gets soft and jelloey.
The issue is time scales. Plastics take thousands of years to degrade but we only really use plastic products for a few years. What can we find that hits a sweet spot of, say, 10 years? Wood does this well, and it’s mostly cellulose. So is paper and this stuff.
Disposable cups, plates, forks, spoons, etc? Sure... eat whatever was in them, throw them wherever, and they'll rot very fast.
Electronics.. mostly not. Maybe some light-up bracelets for a festival, but those also contain batteries and LEDs, but it's still better if at least the strap degrades and rot.
People have been working on bio circuitry for decades now. Not sure of it's utility but man-machine interface comes to mind. I think the fact that it's biodegradable is probably not the point.
As someone that enjoys some (but not all) sodas and kombuchas I really recommend people try several. Don't think all wines/sodas/teas/smoothies etc... are the same. They can be made from just about anything (fortunately/unfortunately)
I loved soda as a kid, and beer in my twenties. Now I quite dislike the taste of alcohol and sugar in the quantities one typically finds in beer and soda, but you're right, there are exceptions I have enjoyed. They've been rare. (I haven't kept track, and I haven't actively sought them out either.)
Store brands are weak, pasteurized, and filtered, such that any unique flavor has been removed to appeal to the average shopper. Drink someone's home-brewed kombucha and you will be blessed with flavors that cannot be found anywhere else.
This goes for all fermented products, such as sauerkraut, yogurt, kefir, and tempeh. Homemade is where all the flavors are preserved.
I love Guava but have not tried it as kombucha yet, definitely should give that a try! My personal favourite is either "ginger" or Canadian Berry (https://www.farmboy.ca/products/farm-boy-organic-canadian-be...). _Very_ different flavour, but could drink those all the time.
Now, how about limiting the fermentation after bottling? I have a couple bottles still in the fridge, that I now call "kombucha grenades." I thought I could open the last one I tried safely, in the sink, and it basically hosed the kitchen and myself. The last few will be outside-only endeavours, wearing a garbage bag like a Gallagher audience member. (Tastes good, at least the half a bottle that is still in the bottle.)
Keep them in the fridge for longer, the carbonation will go down over time.
Also, try placing the bottle in a container or bowl, then hold another (slightly narrower container) over the top of the bottle. You should be able to catch all of the liquid in the bowl to pour into a glass.
If you added a bunch of sugar and/or flavoring into the secondary fermentation / bottles, you added too much. If you didn't add anything, then you didn't let the primary fermentation go long enough.
Oh, guessing the latter, thanks! I hadn't added anything for a secondary or bottling stage.
I am used to regular beer brewing, I think that runs out of steam sooner. Will have to try the two-bowl method.
Yeah. I don't know my kombucha like you seem to, but I've just tried two flavors by two separate brands recently. One (I can't remember what it was) was barely drinkable, second one (hibiscus & rose hips by RISE kombucha) was delicious. It's weird to me to somehow being able to write off a whole family of drinks as undrinkable. I don't like purple Crush, doesn't mean I don't like all colas. I don't like Bombay Sapphire, but gin can be delicious. And so on...
It depends, I genuinely like Kombucha. But it's not a blanket statement for all of them, there's many different flavours and some I dislike, some I like. :)
For me, kombucha has been a natural progression of my exploration into fermented foods. The concept that so many of our favorite foods are produced with the assistance of bacteria is just fascinating to me. The funky flavors of fermented foods is a hurdle, for sure.
When I brewed my kombucha, it was all about how much time do you spend on brewing. In the start it's just very sweet black tea. As time goes, sugar gets processed into acids. With a lot of time, it turns into very acidic mix so it's definitely not something to enjoy and probably not healthy for stomach. So depending on how much time do you spend, you'll get something in between which might be not very tasty or might actually be very tasty.
You can also swap black tea for green tea or other liquids. I'm think that kombucha does not care, all it needs is sugar and tea is for human (although I might be wrong about it).
I actually liked it, but it requires too much housekeeping, so I abandoned it.
The best kombucha I ever had was like drinking vinegar. I happen to love drinking vinegar, just as much as I love drinking lemon juice. Only, that's horrible for one's teeth, so I must restrain myself. I've had kombucha people tell me that vinegar is disgusting and the kombucha I had was "off." Oh well. To each their own.
I brew Kombucha. It's actually delicious, but you need to get a batch made by someone who knows what they're doing. Unfortunately, the latter is hard to come by because there's very little science in Kombucha circles.
Ain't that the truth? So much folklore and superstition about how the fermentation process works. I remember being told you can't make Jun with a Kombucha starter because it's a different bacteria, and even if you did get Kombucha to ferment the honey, it wouldn't actually be Jun. And the complete obsession and misinformation around the pellicle!
The pellicle stuff drives me nuts but I feel pedantic correcting people. I need to find an easier way to observe bacteria, because right now I'm relying on sugar content to determine "doneness", which is pretty second order to all the things that can happen around sugar in a kombucha brew.
I used to make "Kombucha" in the 80s when I still lived in USSR. It tasted really good. The stuff they sell here in stores tastes really bad, mostly like carbonated vinegar.
Cheap, light, flexible, yet robust circuit boards are critical for wearable electronics, among other applications. In the future, those electronics might be printed on flexible circuits made out of bacterial cultures used to make the popular fermented black tea drink called kombucha, according to a recent paper posted to the arXiv preprint server.
As we've reported previously, making kombucha merely requires combining tea and sugar with a kombucha culture known as a SCOBY (symbiotic culture of bacteria and yeast), aka the "mother"—also known as a tea mushroom, tea fungus, or a Manchurian mushroom. It's akin to a sourdough starter. A SCOBY is a firm, gel-like collection of cellulose fiber (biofilm), courtesy of the active bacteria in the culture creating the perfect breeding ground for the yeast and bacteria to flourish. Dissolve the sugar in non-chlorinated boiling water, then steep some tea leaves of your choice in the hot sugar-water before discarding them.
Once the tea cools, add the SCOBY and pour the whole thing into a sterilized beaker or jar. Then cover the beaker or jar with a paper towel or cheesecloth to keep out insects, let it sit for two to three weeks, and voila! You've got your own home-brewed kombucha. A new "daughter" SCOBY will be floating right at the top of the liquid (technically known in this form as a pellicle).
Beyond the popularity of the beverage, kombucha cultures hold promise as a useful biomaterial. For instance, in 2016, an Iowa State professor of apparel, merchandising, and design named Young-A Lee gained attention for her proof-of-concept research in using dried SCOBY as a sustainable leather substitute for biodegradable SCOBY-based clothing, shoes, or handbags. In 2021, scientists at Massachusetts Institute of Technology and Imperial College London created new kinds of tough "living materials" that could one day be used as biosensors, helping purify water or detect damage to "smart" packing materials. Experiments last year by researchers at Montana Technological University (MTU) and Arizona State University (ASU) showed that membranes grown from kombucha cultures were better at preventing the formation of biofilms—a significant challenge in water filtration—than current commercial membranes.
“Nowadays kombucha is emerging as a promising candidate to produce sustainable textiles to be used as eco-friendly bio wearables,” co-author Andrew Adamatzky, of the University of the West of England in Bristol, told New Scientist. “We will see that dried—and hopefully living—kombucha mats will be incorporated in smart wearables that extend the functionality of clothes and gadgets. We propose to develop smart eco-wearables which are a convergence of dead and alive biological matter.”
Adamatzky previously co-authored a 2021 paper demonstrating that living kombucha mats showed dynamic electrical activity and stimulating responses, as well as a paper last year describing the development of a bacterial reactive glove to serve as a living electronic sensing device. Inspired by the potential of kombucha mats for wearable electronics, he and his latest co-authors have now demonstrated that it's possible to print electronic circuits onto dried SCOBY mats.
The team used commercially sourced kombucha bacteria to grow their mats, then air-dried the cultures on plastic or paper at room temperature. The mats don't tear easily and are not easily destroyed, even when immersed in water for several days. One of the test mats even survived oven temperatures up to 200° C (392° F), although the mats will burn when exposed to an open flame. Adamatzky et al. were able to print conductive polymer circuits onto the dried kombucha mats with an aerosol jet printer and also successfully tested an alternative method of 3D printing a circuit out of a conductive polyester/copper mix. They could even attach small LEDs to the circuits with an epoxy adhesive spiked with silver, which were still functioning after repeatedly being b...
The mat at the top of the kombucha is not the SCOBY. It is a waste product of the SCOBY - just a big slab of cellulose. This is a misunderstanding that I've seen people on r/kombucha get pretty upset about
The actual SCOBY is in the kombucha itself, not the cellulose. It's pretty easy to prove; when I made kombucha I would throw out the mat after every batch and save some of the liquid to use as starter for the next.
You also don't need the mat, also known as the pellicle, to start brewing kombucha. It is entirely redundant. Just get a couple of bottles of unpasteurised, unflavoured kombucha and use that as your starter, along with the fresh tea and sugar. Those kombucha starter kits with a pellicle are just a big scam.
You can just use whatever store bought Kombucha to get going. Of course if you find any scoby on Craigslist it's guaranteed to be an interesting encounter
Do you have any reference? I don't think that's strictly true. I agree that this big slab is just some kind of protection, but if you would look at the bottom part of this slab, you would see threads, like small seaweed which "grow" from this slab. My understanding is that kombucha is a symbiotic mix between those threads (it's actually Yeast fungus) and bacteria in the liquid. Liquid does contain some parts of fungus, of course, so you can throw out the entire slab and new slab will grow eventually, but you're throwing lots of yeast and its protection. So your kombucha will take much more time to brew and final result will not have the same proportions of components as "properly" brewed kombucha.
> My understanding is that kombucha is a symbiotic mix between those threads (it's actually Yeast fungus) and bacteria in the liquid. Liquid does contain some parts of fungus, of course, so you can throw out the entire slab and new slab will grow eventually, but you're throwing lots of yeast and its protection.
On the other extreme: if one has an old enough continuous ferment, a lot of yeast will settle at the bottom, potentially affecting the end result.
I'm always fascinated that most cultures have some fermented foods in their cuisine. I often wonder how they came up with it. Extreme thirst or hunger? Curiosity? Or have they slowly 'evolved' in a way that people let them ferment more and more over time?!
I have a bunch of weird hobbies, including things like brewing mead, making cheese, and yes, I have made kombucha. Years ago when they were still in a garage, I walked into the "office" of what is now a nationwide kombucha brand. I didn't know anything about kombucha but there was a lot of hype about these people. I started asking questions and was directed to the "head brewer." I wanted to talk microbiology, but it was very evident they had no effing clue what was actually in their mother culture. Sure, they knew how to dump it into their tea, but that was about it. Not very long after that, they had reached national distribution. I think there are a lot of lessons in there for people who are worried about imposter syndrome or people who think all you do is build a better mousetrap, as it had nothing to do with their product and everything to do with the founder having deep ties to the grocery world.
Absolutely - as far as I know, they had just one founder, who was very clearly a sales / marketing type. My guess is that they didn't really have any passion for kombucha (I only met them once, by accident really, so don't know the story...) but had done the research on a product that was primed for commercialization.
When it comes to fermentation, you can get pretty far by developing a good intuition (through experience) of how to steward your little ecosystem and how it responds to your particular ingredients and environment. You can be an expert on that and produce great flavors without knowing the microbiology, like cheesemakers and brewers have done for thousands of years.
Granted, the hard science is helpful in getting to the next level and achieving a product that's consistent from batch to batch.
>Granted, the hard science is helpful in getting to the next level and achieving a product that's consistent from batch to batch.
That was the part that was eye opening. It's one thing if I'm making something in my kitchen for my use, it's another when you have already achieved regional distribution of a product but clearly have no idea what's actually in it.
If I'm not mistaken a lot of fermented products are in a similar situation. For example yes we know yeast makes wine, but how about the other microbes that contribute to its subtle flavors? We know what makes cheese, but why does cheeses made in a region taste different from another? (note: cheeses in the US has much less variety in tastes due to super standardized industrial processes, but European cheeses do exhibit this behavior, often attributed to different microbiological environments)
I've been trying to find info about the science of fermentation of soy sauce, and I haven't been able to get much info. I suspect we don't really know what's in those cultures either.
I had a HORRIBLE epic that spanned 2-3 years of unknown gastro problems. I blame Kombucha 100% for rotting my insides. A cup every now and then is ok but if you drink it daily (like I did) in large doses (like I did) and make your own (which I tried to save money) you'll soon realize it's essentially VINEGAR. I wont get into the specifics but stay away from this stuff at all cost. Try some cashew yogurt or other pro-biotic foods. Long term Kombucha drinkers tread lightly.
How much were you drinking? I have never heard anything like this.
If you brewed it at home, then you should know that yes, acetobacter the bacteria part of the SCOBY converts the alcohol that the yeast creates from the sugar into acetic acid. Vinegar is 5-8% acetic acid.
This isn't secret, sacred knowledge. Sounds like you over did it, no need to spread your FUD around.
I feel like I often see breakthroughs in natural material computing like this but they never seem to make it to market that I've noticed. What am I missing? It seems like everyone would want to move in the direction of sustainable computing materials.
99 comments
[ 11.0 ms ] story [ 645 ms ] threadI’m going to go out on a limb here and say, yes.
> In the US, a single fab, Intel’s 700-acre campus in Ocotillo, Arizona, produced nearly 15,000 tons of waste in the first three months of this year, about 60% of it hazardous. It also consumed 927m gallons of fresh water, enough to fill about 1,400 Olympic swimming pools, and used 561m kilowatt-hours of energy. (source https://www.theguardian.com/environment/2021/sep/18/semicond...)
Kombucha on the other hand, yes produces CO2 as a waste product, but it is very easy to see a kombucha SCOBY being carbon neutral. That is the source of it's sugars being carbon energy free, and the manufacturing process of SCOBY circuits as well. Then it's carbon neutral
Doing a CPU out of a scoby would be real bio computing :)
On the other hand, buying a gadget that dissolves when it gets just a bit wet might not be a smart thing...
But i can totally see them selling "biodegradable" flashing LED bracelets (or similar single-use crap), where the bracelet iself is biodegradable, and the rechargable battery (without an actual charging circuit) and plastic potted LEDs are not....
Disposable cups, plates, forks, spoons, etc? Sure... eat whatever was in them, throw them wherever, and they'll rot very fast.
Electronics.. mostly not. Maybe some light-up bracelets for a festival, but those also contain batteries and LEDs, but it's still better if at least the strap degrades and rot.
Edit: Ignore. As commenter pointed out it's still paywalled.
https://arxiv.org/abs/2302.03984
As someone that enjoys some (but not all) sodas and kombuchas I really recommend people try several. Don't think all wines/sodas/teas/smoothies etc... are the same. They can be made from just about anything (fortunately/unfortunately)
Those two products have tens of thousands of flavor profiles, it's strange to me that you can dismiss them entirely.
I had a red velvet cheesecake craft beer the other day and there was no hint of "beer" in it.
I like everything, and I've never had kombucha, so this thread has me excited to try it... Many times, for the various flavors!
This goes for all fermented products, such as sauerkraut, yogurt, kefir, and tempeh. Homemade is where all the flavors are preserved.
I am brewing 5 flavors right now in my house. I assure you, they are delicious.
Guava Jasmine is my current favorite.
But keep hating on it if you like, you're missing out on something great.
This is the basic recipe I use: https://www.reddit.com/r/kombucha/wiki/how_to_start#wiki_mas...
For more information, The Big Book of Kombucha will have everything you need and more.
Have fun! :)
https://www.youbrewkombucha.com/scoby-care-hotel
(Just passing by; I have no personal interest in kombucha, was simply unaware of the term.)
Also, try placing the bottle in a container or bowl, then hold another (slightly narrower container) over the top of the bottle. You should be able to catch all of the liquid in the bowl to pour into a glass.
If you added a bunch of sugar and/or flavoring into the secondary fermentation / bottles, you added too much. If you didn't add anything, then you didn't let the primary fermentation go long enough.
You can also swap black tea for green tea or other liquids. I'm think that kombucha does not care, all it needs is sugar and tea is for human (although I might be wrong about it).
I actually liked it, but it requires too much housekeeping, so I abandoned it.
See how that works?
As we've reported previously, making kombucha merely requires combining tea and sugar with a kombucha culture known as a SCOBY (symbiotic culture of bacteria and yeast), aka the "mother"—also known as a tea mushroom, tea fungus, or a Manchurian mushroom. It's akin to a sourdough starter. A SCOBY is a firm, gel-like collection of cellulose fiber (biofilm), courtesy of the active bacteria in the culture creating the perfect breeding ground for the yeast and bacteria to flourish. Dissolve the sugar in non-chlorinated boiling water, then steep some tea leaves of your choice in the hot sugar-water before discarding them.
Once the tea cools, add the SCOBY and pour the whole thing into a sterilized beaker or jar. Then cover the beaker or jar with a paper towel or cheesecloth to keep out insects, let it sit for two to three weeks, and voila! You've got your own home-brewed kombucha. A new "daughter" SCOBY will be floating right at the top of the liquid (technically known in this form as a pellicle).
Beyond the popularity of the beverage, kombucha cultures hold promise as a useful biomaterial. For instance, in 2016, an Iowa State professor of apparel, merchandising, and design named Young-A Lee gained attention for her proof-of-concept research in using dried SCOBY as a sustainable leather substitute for biodegradable SCOBY-based clothing, shoes, or handbags. In 2021, scientists at Massachusetts Institute of Technology and Imperial College London created new kinds of tough "living materials" that could one day be used as biosensors, helping purify water or detect damage to "smart" packing materials. Experiments last year by researchers at Montana Technological University (MTU) and Arizona State University (ASU) showed that membranes grown from kombucha cultures were better at preventing the formation of biofilms—a significant challenge in water filtration—than current commercial membranes.
“Nowadays kombucha is emerging as a promising candidate to produce sustainable textiles to be used as eco-friendly bio wearables,” co-author Andrew Adamatzky, of the University of the West of England in Bristol, told New Scientist. “We will see that dried—and hopefully living—kombucha mats will be incorporated in smart wearables that extend the functionality of clothes and gadgets. We propose to develop smart eco-wearables which are a convergence of dead and alive biological matter.”
Adamatzky previously co-authored a 2021 paper demonstrating that living kombucha mats showed dynamic electrical activity and stimulating responses, as well as a paper last year describing the development of a bacterial reactive glove to serve as a living electronic sensing device. Inspired by the potential of kombucha mats for wearable electronics, he and his latest co-authors have now demonstrated that it's possible to print electronic circuits onto dried SCOBY mats.
The team used commercially sourced kombucha bacteria to grow their mats, then air-dried the cultures on plastic or paper at room temperature. The mats don't tear easily and are not easily destroyed, even when immersed in water for several days. One of the test mats even survived oven temperatures up to 200° C (392° F), although the mats will burn when exposed to an open flame. Adamatzky et al. were able to print conductive polymer circuits onto the dried kombucha mats with an aerosol jet printer and also successfully tested an alternative method of 3D printing a circuit out of a conductive polyester/copper mix. They could even attach small LEDs to the circuits with an epoxy adhesive spiked with silver, which were still functioning after repeatedly being b...
The actual SCOBY is in the kombucha itself, not the cellulose. It's pretty easy to prove; when I made kombucha I would throw out the mat after every batch and save some of the liquid to use as starter for the next.
On the other extreme: if one has an old enough continuous ferment, a lot of yeast will settle at the bottom, potentially affecting the end result.
[0]: https://jessie.fandom.com/wiki/Moby_%26_SCOBY
Sometimes the result smells ok.
Eventually somebody is curious enough to try it.
Or "just" hungry enough
Granted, the hard science is helpful in getting to the next level and achieving a product that's consistent from batch to batch.
That was the part that was eye opening. It's one thing if I'm making something in my kitchen for my use, it's another when you have already achieved regional distribution of a product but clearly have no idea what's actually in it.
I've been trying to find info about the science of fermentation of soy sauce, and I haven't been able to get much info. I suspect we don't really know what's in those cultures either.
From an outsider perspective, they might be indistinguishable, but I would be shocked if the biggest brands have not done their own research.
https://patents.google.com/patent/WO2017153618A1/en
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8348054/
Apparently similar applies to Whiskey:
https://qz.com/907619/the-many-scientific-ways-to-age-whiske...
https://www.pastemagazine.com/drink/whiskey-/rapidly-aging-w...
https://robbreport.com/food-drink/spirits/distilleries-using...
https://homedistiller.org/forum/viewtopic.php?t=66552
SACRILEGE!
If you brewed it at home, then you should know that yes, acetobacter the bacteria part of the SCOBY converts the alcohol that the yeast creates from the sugar into acetic acid. Vinegar is 5-8% acetic acid.
This isn't secret, sacred knowledge. Sounds like you over did it, no need to spread your FUD around.