SCOBYs Are Useless

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Sdaji

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I've been experimenting with not using SCOBYs when setting up cultures. I get lovely, thick, well-formed SCOBYs. I started wondering how adding a SCOBY was doing anything, since I heard about other people using the old SCOBY to make their next batch. The old SCOBY is submerged, sometimes even sitting at the bottom of the jar. The SCOBY of course is where the bacteria sit at the surface, so they can stay wet but have access to lots of oxygen. If the SCOBY isn't on the surface it's just a meaningless piece of cellulose, and that's what lots of people use rather than the active one on top.

I tried making cultures without SCOBYs. Not surprisingly, they grow SCOBYs just as quickly as the cultures with starter SCOBYs. I usually add about 10-15% kombucha and 85-90% sweet tea, and a SCOBY (or piece of one). If I make two batches side by side and give one a SCOBY and the other the same volume in extra kombucha, the one without the starter SCOBY actually brews faster and grows a new SCOBY more quickly, with no difference in 'quality' (as judged by my taste buds), just a slightly shorter brewing time. I interpret that as there being more microbes in the liquid than in the SCOBY (which is basically just permeable cellulose with a bit of liquid). I did wonder if there would be lots of bacteria in the SCOBY and more yeast in the liquid, and perhaps that is the case, but either way, there is obviously plenty of everything in the liquid.

I think using old SCOBYs is especially meaningless. You're just putting some inert byproduct into your new culture.
 
Right the scoby isn't absolutely needed if you have enough starter tea in the mix. It is a bit of an art to keep the scoby at the top when cleaning out the brewer or starting a new batch. I'd say my scobies float, sometimes with a little help, about 75% of the time. Sometimes they insist on sitting about an inch below the top and then of course a whole new scoby grows.
 
I've tried it in side by side brews lots of times now. Say, a litre of new sweet tea in each, 50ml of liquid and a 50ml SCOBY in one and 100ml of liquid and no SCOBY in the other. It seems the liquid actually contains more microbes, or maybe it's that the extra starter tea reduces the pH and adds more alcohol etc. than a SCOBY would so the new brew gets going faster. Either way, it's not just that the SCOBY isn't necessary, it doesn't even seem beneficial. I'm actually wondering if the SCOBY is even something the bacteria build to give themselves a place to live, or if it's just the the cellulose is a byproduct they produce and since they are active at the surface that's where the cellulose is created. If so, the SCOBY might actually just be a waste product which gets in the way and stops the brew working as well by creating a barrier between the liquid and air. Obviously it's not a significant problem and I wouldn't bother trying to remove the SCOBY mid brew, but I wonder if it's actually a slight problem or a benefit having a SCOBY there at any time. Certainly, the term SCOBY seems like a complete misnomer.
 
Hm well it's definitely an interesting observation. Maybe you're right about it being a waste product, since the scoby seems to just grow and grow and grow and eventually will take over the entire brewer if it gets the chance.

I was thinking more about this today, maybe you could do this as an experiment? How about every day or every other day you scoop of any scoby that has started to form? And compare that with a batch where the scoby is allowed to grow normally, to see how the end products of each are?
 
I personally do not think SCOBY's are useless. Case in point, I started a batch of kombucha and forgot to add the starter tea (did not realize until MANY days later), but had added my SCOBY as usual and my kombucha turned out just fine (took it a bit longer but it was just fine). Also, I do not believe that a sunken SCOBY is a dead SCOBY--many different school of thought on floating vs. non-floating. I replace a SCOBY when it actually starts to shrink, it is a visual inspection for me. FWIW.
 
porcupine: I've wondered about that. I imagine it would brew normally, but it would be interesting to try.

saramc: The 'SCOBY' is porous, like a sponge. I could get the exact same result you did by putting a plastic sponge in some liquid kombucha and putting that into the starter tea. It wasn't the inert cellulose that made your brew work, it was the microbes and liquid in the SCOBY. Alternatively, I could get a SCOBY, dry it out, sterilise it, soak it in kombucha then put it into some sweet tea and make a new batch. Alternatively you could get a SCOBY and wring it out so the expelled liquid falls into a new batch of sweet tea. That would work too. It's possible that the bacteria adhere to the SCOBY and have higher numbers there than in suspension, but your experience actually suggests against that, because your brew took longer. I must admit, I haven't tried using SCOBY only with no liquid to start a new brew. I'll give it a go some time, comparing an equal volume of SCOBY alone to liquid alone.

The SCOBY is never 'alive', so no, a sunken SCOBY is not a dead SCOBY, it's just a sunken mass of cellulose which used to be a floating mass of cellulose.

The SCOBY itself is very clearly not a 'plant' or 'mushroom' or any sort of living thing. They never grow, new layers of cellulose just get piled up at the surface of a kombucha culture. If there's already a layer right at the surface the new cellulose is attached to the old and the mass gets larger. If the top gets covered by liquid the new cellulose just piles up above it in a new layer. It is not stored for later use, it is inert, it doesn't do anything a life form would be expected to do, it does behave very much like a pile of waste product, or at most, non living structural framework. We do know that the living things in kombucha are single celled. We also know the the SCOBY is non cellular, so very obviously the SCOBY itself is not alive. Whether it is made as a functional product (a living platform of sorts is the only likely possibility) or simply waste product is the only reasonable question.
 
I don't dispute that you can grow a baby scoby with starter tea only (without adding a mother scoby to the brew) because the starter tea should have a mixture of yeast and bacteria. But I don't think you're correct about the scoby being a dead wast product. My understanding is that the bacteria in the scoby is very much alive, mixed in with the cellulose substrate that it is creating as it ingests the tea tannins and caffeine. I thought the bacteria also sorted themselves into anaerobic toward the bottom (submerged in the tea) and aerobic on the top (at the air/scoby interface).
 
There are live yeast and bacteria in the SCOBY, just as there are live people inside a bus or a building. Or maybe it's more like there are live pigs in a pig pen, and after a while a layer of $H!t builds up on the bottom and if you were too large to see an individual pig and picked up a big scoop of the $#!t you'd get some pigs with it, and perhaps think that the $#!t itself was self replicating. Buses and $#!t are still not living things, they are things created by living things, and on their own won't replicate. I really do think that by introducing the SCOBY to the new batch we're just dragging a bit of waste product along the way, or perhaps the equivalent of a burned out house which is no longer habitable.

The bacteria are facultative anaerobes. The same bacteria can switch between being aerobic and anaerobic or a bit of both at the same time depending on the conditions.
 
Hi dcshare, the scoby will either repair itself if say it has a hole in it but it is still floating. If part of it sank, a new scoby will form. When the scoby is thin it is easily injured.
 
thank you for the reply and for helping me out.... I was also wondering if you can add kombucha to shampoo or if it would have any effect topically or not...
 
I think you could add it to shampoo, I think some people apply it afterwards as a conditioner almost.

It works great on the skin all over the body. It feels a little weird and smells a little funny at first but it quickly goes away, it seems to really benefit the skin.

I like to use well aged and soured kombucha for those purposes so there is as little residual sugar as possible.
 
I thought the Scooby is like a yeast starter for beer.. it has allot more yeast and bacteria cells stored up in the pellicle membrane than just the liquid kambutcha in its self.. I've taken a hiatus from kambutcha for a while but am having problems with my gout again so I'm starting up a 2 gallon continuous set up so I can pull 2-4ltrs off a week..
 
That sounds nice, yes continuous is my favorite method. I can average about 2 20 fl oz bottles per day from each 2-1/2 gallon brewer.

It has taken me a year to finally get a good consistent brew but I have my system down now. Most recent discovery is the use of Woodstock Farms cane sugar in the bottles during second ferment - it adds this absolutely amazing buttery toffee flavor and adds tons of carbonation. I have gotten the carbonation with other cane sugars but none others I've tried have had that buttery toffee flavor like the Woodstock Farms. That with ginger and elderberry left to second ferment for a few weeks seems to do the trick.
 
You track your gravity at all? With my 1 gal batches in the past I think I was using about 6 ounces and got around 1.015-1.020, somewhere around there.. can't remember..lol.. seemed like if I went over that I started getting the unpleasant vinegar burn.. might even do a little less this time around.. :mug:
 
I don't track the gravities at all, I just go completely by taste. Sometimes yes they do get a little bit strong if I leave them in 2F for too long. Up to about three weeks it seems OK as long as the temps aren't too high. It seems like they don't get very vinegary in the second ferment in the sealed bottles but they will get pretty strong almost throat burning feel to them. I've got probably 100 or so ez-cap bottles I rotate through. I usually drink about four or five a day. That might be too much of it to drink though I'm not sure. I like them bone dry after 2F, I don't like it sweet at all. If I leave it too long in the continuous fermenter yes that gets really nasty strong vinegar tasting.
 
i have this scoby in my fridge from last december in a bag.. im gonna try and get a liter batch going with it.. if not ill just get a bottle of GT again.. i also want to try and induce brett into it for the main yeast!!
40024d1323294003-star-san-sanitise-forumrunner_20111207_143954.jpg
 
Hm interesting, looks pretty thick and leathery. Seems like it might take a bit for the yeasts to get active again, I might put it and some of the tea in a 'sacrificial' starter batch with a little fresh sweet tea for at least a few days to try to get her going again before trying to actually use her in brewing. Hm what is the addition of Brett you mention, I am not familiar?
 
Hm interesting, looks pretty thick and leathery. Seems like it might take a bit for the yeasts to get active again, I might put it and some of the tea in a 'sacrificial' starter batch with a little fresh sweet tea for at least a few days to try to get her going again before trying to actually use her in brewing. Hm what is the addition of Brett you mention, I am not familiar?

yeah, the liter batch would be the sacrificial starter to see if it will get going again.. this scoby is around 12 generations thick.. brettanomyces is a wild yeast that grows on most fruit and concidered a flaw in most styles of beer.. if you contaminate your equipment with it it is hard to get rid if the contaminent without buying new stuff.. it adds a complex range of flavor to sour ales (funk)..
 
when i get home tinight after my curling league i will post a pic of it in the bag and you can let me know what you think when ya get a chance.. if i remember it was getting dark so i decided to stop brewing it cause i had a little supply built up.. was even thinking about frying it up and making a burger outta it..lol.. :mug:
 
Here It is.. it's been moved around allot and all the layers shifted but you can definitely see how much yeast builds up in the membrane (the darker parts are allot darker than what the pic shows) but I guess the yeast vitality is in question not the bacteria.. hope I can get to it tomorrow..

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Looks nice, seems like it would probably still be viable. I'm sure you'll know after the first sacrificial batch. If you do end up needing a new one, let me know I could drop one in the mail to you. I have about three water crock size 10" scobies I put in the compost ever couple weeks when I clean out my continuous brewers.
 
i did infact get a new batch going from my old scoby and played with it. seperated new growth from the old scoby and tried fermenting wort with the old but kinda forgot about it but can smell it every once in a while when i bump the cabinet its on top of..lol.. turned the new generated scoby into a starter for a continous batch. got a glass 20 ltr drink dispencer from a lady at work but need to put a new valve on the bottom of it because it has a brass one on there now. kinda busy and working alot so i put my kombucha on the back burner. ill try and get back into it after my kids birthdays at the end of the month.. :mug:
 
Nice thing about KT is you can be super lazy let it sit for months, drain the vinegar/liquid completely, add starter and you're good to go
 
I got lazy with my cultures, left them all for months, tried to make new batches from them and none of them worked. Well, some smell like kombucha, some have SCOBYs but all have mould as well. Damn. I'll have to outsource a new culture!
 
I got lazy with my cultures, left them all for months, tried to make new batches from them and none of them worked. Well, some smell like kombucha, some have SCOBYs but all have mould as well. Damn. I'll have to outsource a new culture!

I think I got lucky with mine! When I put it in the fridge it was towards the end of a batch and i think i got some something still alive between the layers! This is ripe for a 5 gallon batch! I NEED to do it this weekend!!!.. I'll start with a gravity around 1.015 and see where it sits after a week.. good; and I'll bottle with whatever I want that contains sum sugar, if not i'll check daily!! Hope I can get too it!! Got one of my girls birthday this weekend :mug:

ForumRunner_20130308_010100.jpg
 
Ok....I gota ask.....what the hell is a Scoby, and why is a picture of one in a plastic bag as part of a thread with 29 replies to the post always pictured on my front page of HBT.
 
Ok....I gota ask.....what the hell is a Scoby, and why is a picture of one in a plastic bag as part of a thread with 29 replies to the post always pictured on my front page of HBT.
Symbiotic
Colony
Of
Bacteria and
Yeast

A scoby is generated by the bacteria in a kombucha starter as they convert alcohol from the yeast into acetic acid.

This thread is discussing the usefulness of the scoby it's self in kombucha, outside of the presence of yeast and bacteria.

Kombucha is basically fermented sweet black or green tea.

Happy Brewing!
:mug:
 
The thick membrane that forms on the surface of your brew Symbiotic colony of yeast and bacteria (SCOBY) is what the living culture in the starter tea builds to create an enclosed area for in which the starter tea can safely and sufficiently eat and build up its colony of bacteria and yeast like a healthy town. The more healthy your colony living in your brew the healthier and more evenly developed SCOBY "mushroom" will grow... The scoby is a slight Bi product of brewing booch but a very dense and bacteria ridden environment for a quicker and more efficient kombucha brew. I started brewing Kombucha Large scale for market sales and its interesting when your brewing 15gal batches of it ... i think the beer and kombucha can reside with one another some how... i just read a guy brewing green tea beer and kombucha LOVES green and blk tea!
 
I know that kombucha is not the most popular research topic for biochem Phds, but how long have we known that the SCOBY (seems like a misnomer since the physical floater is not the culture itself) was just a hunk of cellulose? I started brewing barely 6 months ago and every post I read on this forum - as well as every link I found on the internet - told me to add the SCOBY to every batch. Now I am reading that this growth is like a massive pellicle (funky beer term, look it up) and nothing more, and that it may not even speed up the fermentation.

Also, a question:

If I harvest the SCOBY after each batch and keep forming new ones, what can I do with the cellulose? Links?
 
You will have a much faster primary ferment with the addition of a scoby, all tho you can brew with just starter, the process takes 3 times longer to produce a quality kombucha. The culture will spend more time building a new membrane on the surface of your vessel. Or you help it by placing a scoby with your starter tea and the job gets going much faster. Not to mention the scoby is loaded with tons of culture as well. the more the merrier.

I brew 15gal every 8 days and the amount of SCOBY i have is insane. I chop it up and feed it to my dogs, cats and my chickens love it! People also dry it and use it as a leather replacement. Ive seen a SCOBY wallet before. A dry SCOBY will take about 2 weeks to completely rehydrate so its actually has great water repelling qualities.

And my favorite thing i love to do with all the SCOBYs is sell them! or give them away!
 
You will have a much faster primary ferment with the addition of a scoby, all tho you can brew with just starter, the process takes 3 times longer to produce a quality kombucha. The culture will spend more time building a new membrane on the surface of your vessel. Or you help it by placing a scoby with your starter tea and the job gets going much faster. Not to mention the scoby is loaded with tons of culture as well. the more the merrier.

I brew 15gal every 8 days and the amount of SCOBY i have is insane. I chop it up and feed it to my dogs, cats and my chickens love it! People also dry it and use it as a leather replacement. Ive seen a SCOBY wallet before. A dry SCOBY will take about 2 weeks to completely rehydrate so its actually has great water repelling qualities.

And my favorite thing i love to do with all the SCOBYs is sell them! or give them away!
Interesting. Have you done head to head batches with and without scoby? I'm not sure about kombucha, but with rice wine I've found that there are to many variables to get useful data unless the batches are running at the same time.
 
A SCOBY is not needed to start a batch of KT. Large brewers inject oxygen into their tanks to keep them from forming and to feed the yeast. A SCOBY is, however much it contains dead cells, alive. The top layer is very active, in fact.

Making dozens of batches side-by-side, some with SCOBYs and some without, I find a couple things. Both will brew nice kombucha - and SCOBY-less brewing can often produce a better brew because it takes longer and more of the alcohol is turned into acids. However, in my tests a SCOBY-less brew is less protected (has fewer of the beneficial bacteria cells you want) and will more often, under regular conditions, allow for non-beneficial bacteria to interfere. You might also wonder why the formation of a top layer at all? Is it to seal of the oxygen in the battle for resources between yeast and bacteria or simply to capture all of the escaping alcohol?

Perhaps the bacteria, which require oxygen, fill with gas and produce a raft as an evolutionary mechanism in order to allow a specific colony to thrive. It's the top layer that is most active, after all, and it's also the top layer that often doesn't touch liquid but is fed by slight moisture, escaping alcohol and gasses trapped between the top of the liquid and the container -- which brings up questions regarding the type of container (tall or wide) and the type of covering (very tight, not tight at all). I've found narrow tops using coffee filters produces a much different brew than a wide top using a cloth covering. I'm just guessing, but I believe this is because there is a battle between types of bacteria (some that live in liquid, some that need to float; some that can survive in an environment rich in gasses, some that require more oxygen) while concurrently battling with the yeast (top or bottom forming), which can switch between being aerobic and anaerobic.

You can brew KT with lots of different sugars, lots of liquids, in many containers and using SCOBYs or not, injecting oxygen or adding yeast and bacteria directly into your brew ... but it begs the question: What are you trying to achieve with your brew?

I say this because my current issue is how to up my bacteria count and slow my processing time in order to reduce alcohol. It seems that using the new SCOBY layer (rather than no SCOBY), reducing ambient heat, and directing my heat source to the top of the tank rather than the bottom will increase the bacterial activity and, given the types of bacteria I'm growing (Gluconacetobacter), increase sweetness while lowering alcohol, since my sugar is already at negligible levels.

Okay, so that got a little derailed.
 
such an interesting post. I just watched a video by House Kombucha owner. She said in the vid (which seemed to be a few years old) that the company never saves the SCOBYs. They toss everyone after every single new batch is made. I was like, "WHA???". The video is at the very bottom of their website page. I've never tried the brand, so I have no idea what it's like but I thought it was interesting.
 
I tried 1 gallong of tea (8 green tea bags), 1 cup of sugar, and two cups of kombucha with no SCOBY. After a week I just had a mold colony. Temps mid 60s to mid 70s. I've only made KT a few times (before realizing I don't drink enough to keep the pipeline going & went back to buying it) and just googled a recipe.

Tonsmeire says "If you go too big too fast the microbes will take a long time to grown and ferment and might get overrun by the local microbes who might not make such a tasty beverage." http://www.themadfermentationist.com/2007/03/culturing-kombucha-from-commercial.html

Are you guys doing something else to make sure that you don't get overrun by bad bugs? Is it possible you have the kombucha bugs floating in high concentrations in the air where you ferment it? Did I just screw up my recipe or ferment too cold?
 

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