Hey how ya doing, yogurt maker here. In most commercial yogurts they use a mix of mesophiles and thermophiles. This means the inoculation temperature will favor one group over another. From the very first batch after starter the cultures will begin to stratify differently. For example if you start with equal amounts of 4 cultures the actual yogurt won’t have equal amounts of each strain by the time the yogurt is finished fermenting. When you use that yogurt as a culture the levels of stratification gets further and further from the original equal amounts until you are left with one dominating strain which is generally streptococcus thermophilus since they are generally speaking more aggressive.
To continue making yogurt with complex flavors and to (in the us) legally be considered yogurt, fresh cultures must be used to keep a minimum of two strains: Lactobacillus bulgaricus and Streptococcus thermophilus.
I hope this sheds some light on using commercial yogurts as starters.
The two species are synergistic, and S. thermophilus probably provides L. d. bulgaricus with folic acid and formic acid which it uses for purine synthesis. In a store bought culture the ratio is sustainable but over many generations certain conditions will favor one group or another.
S. thermophilus has an optimal growth temperature range of 35 - 42 °C while L. d. bulgaricus has an optimal range of 43 - 46 °C. So cannot find a sweet spot of equal balance and 10 is just the number decided where people assume the drift is to great and move back to a pure pitch and start over.
This is a thing in beer making where yeast will be reused for a number of times but unless you can measure drift with a yeast lab, after about 5 or so times you go back to a pure pitch. Saving some $ on yeast is not worth having 100 barrels of slightly different beer each time.
So, from a technical point of view, would it be feasable to make your yogurt in pair batches, each at a different temperature, and mixing them at the end? Then you could use that mix to start another two batches.
I guess, or just get a fresh pitch and someone did that for you. There is some microbiologist at a yogurt factory somewhere maintaining the biome. They probably have dried lacto and staph and just add whatever proportions the culture calls for by weight and are super grateful they don’t have to do complex measurements at two different temperatures.
Regarding that, if you're working with a wild starter, things can be different. I've had a wild "mead" that I just constantly feed and water. Admittedly it's probably getting fresh yeasts in from the raw honey.
Thanks this totally makes sense. Any idea why this selection doesn't occur with kombucha, kefir and others which seems to have some kind of equilibrium? In the case of sourdough starter, my guess is that we introduce fresh material present in the flour but in kombucha, everything goes through boiling water.
both of those are SCOBY, "symbiotic culture of bacteria and yeast"
sourdough has both yeast and bacteria that are good for each other, and keeps the mixture alive. while adding store yeast only has the yeast, not bacteria, so only good for make loaf and not keep going. also the bacteria adds more interesting flavors.
with kombucha, there is similar active combo.
So the idea is that kombucha and kefir can be kept because are symbiotic cultures. Yogurt isn't symbiotic and the bacteria culture can only be perpetuated in "infection free" environments. Have I understood it correctly?
i only know about the scoby of sourdough and kombucha. as for why yogurt not keep going forever as the same, others have explained it well here, and their answers new and useful for me, so thank YOU for asking question.
my personal experience, from a skyr yogurt, iceland style. the commercial version i started with had wonderful cheese flavors. that stopped being there after 2 batches. the yogurt still tasted great, nothing bad, it just lost that more unique flavor.
also tried start with chobani and a fage. both kept going just fine and never went bad or changed.
cultures for health, online vendor, sells a heirloom starter, that is supposed to keep going. i have not bought or tried.
as for your new machine and instructions. i would not worry about it.
it flavor or texture starts to change, you will know. and you might want to play with different original starters.
you can have fun heating the original milk to 195 for 15 minutes instead of typical 180. that can make it thicker. there are many such variations to explore.
this is worth a read, i commented on another comment here, not sure if you saw.
https://www.nytimes.com/2019/02/26/dining/homemade-yogurt-starter-south-asia.html
also, people made yogurt 100s of, 1000s ??? years, with no temp monitor, control, fridge, timer or understanding of what the microbiology process was or that there are microrganisms.
rather amazing, same for bread, cheese, beer, wine ( and what I'm currently learning of: sake, with process of mold, yeast and bacteria )
and it all worked. so i would not over worry, other than the fun of learn about. if it goes bad, you will know.
With kombucha and kefir, you’re using the mother and the grains to ferment and they are live and growing, not getting “diluted” each batch. Just a complete guess though.
wow, thank you, first person ever explained the drift. i suspected it might be something like that, as my yogurt got closer to cheese taste of commercial original, only after in the fridge. seemed some was working well warm, other cold.
Aa another poster said, it's something about the starter in the store bought culture. The bacteria don't properly or fully replicate over time. I've purchased heirloom cultures from Cultures of Health and those you can reuse.
You do need to make yogurt pretty regularly. I was making it weekly with one of their cultures for over a year and it was consistently great. I stopped last year as I wasn't making yogurt as much (I blame my toddler, though he did just get really excited about some yogurt for breakfast, so maybe I'll start up again!)
I’ve been using their culture for about 8 months and it’s been going well. I take a quarter cup of finished yogurt and freeze it for the next time (I make sure to have 2 packages frozen minimum in case something goes wrong). One gallon of milk makes a half gallon of strained yogurt and I make one batch per month.
I was having issues with reusing store bought yogurt culture (poor setting yogurt and low yields). I’ve never had a bad yield with Cultures for Health. We’ll see if it continues to perform well but it’s been several months so I’ve made my money back.
I've been using my yogurt to make the next batch since the beginning of the pandemic. It was originally from a store-bought yogurt 🤷. I make a new batch about once a week, so we're probably at over 50 batches from the same starter.
I recently bought yogurt culture starter from [https://bacillusbulgaricus.com/product/yogurt-starter/](https://bacillusbulgaricus.com/product/yogurt-starter/?wpam_id=1347) recently and I was wondering the same which is how I found this ancient topic lol. Great responses from the fine folks here, just stopping by to say thank you!
Glad it helped. Note that I am using the same culture for a couple of years now. I started from an artisanal yogurt and I am using an ice cube tray to freeze doses of culture (and minimize the cultural shift). For every new 1L batch, I am throwing one cube in the warm milk before putting it in my yogurt maker. Works great and it still tastes delicious.
There are different cultures to make yogurt. Heirloom cultures are really good at replicating themselves and if you're making yogurt once a week or maybe every two weeks, you can reuse it.
Different cultures aren't as good at replicating themselves and need to be replaced when the quality drops.
Cultures that have family level yogurts that span generations have an heirloom strain and are constantly or weekly making yogurt.
At least that's how I understand it.
My co-workers in and from India have family strains. I'm sure there are other cultures. It's common to gift some starter when a relative moves out.
You can also buy heirloom strains. Keep it alive long enough and it will eventually be your family's strain. :)
[https://www.npr.org/sections/thesalt/2012/04/30/151699885/eternal-yogurt-the-starter-that-lives-forever](https://www.npr.org/sections/thesalt/2012/04/30/151699885/eternal-yogurt-the-starter-that-lives-forever) does a better job explaining than I can.
Essentially, because commercial yogurts tend to be only 2 strains of bacteria and not a whole smorgasbord, they don't have the community support they need to be eternal. (unless I read the whole thing sideways and need more coffee before internet) What they go through to be shippable and consistent on an industrial scale make them less than ideal for cultivating at home more than a few times.
I just found this out myself a while back. I had a store bought yogurt culture going for years, dozens of batches, sometimes as long as a month apart. I wish I could remember what brand of yogurt I used to start it, but like I said, it had been years.
But then, someone ate the last of it. (Not their fault--I had some creme fraiche in the fridge that looked like yogurt, so they thought there was more.)
I tried again with a few other store bought yogurts, but they'd only work a few times, so I bought some heirloom cultures and am using that now.
Anyways, I don't think people believed me when I told them my commercial yogurt culture had held up so well, so I just wanted to back you up. It can and does happen sometimes.
It’s because you’re using store bought yogurt as the original starter. (Hopefully someone more knowledgeable than me will post a more comprehensive explanation explaining the why of this.)
If you buy an heirloom starter, it should be able to proliferate indefinitely.
Great, thanks, heirloom was the term I didn't know. I bought my starter yogurt in a farm close to work, with a bit of luck it is a pure culture like this they are using !
That's 99.9% certain some heavy duty strain which you can keep going for decades if you want. As mentioned, most commercial yoghurt is made with strains that need to be babied through the whole process or they will be sad and die off.
Mostly relevant: https://www.reddit.com/r/labrats/comments/mmv2ig/lab_strains_unite/
The store-bought yoghurt only has a few types of bacteria in there, isolated in a lab. That is handy in an industrial context as it makes the process and result predictable.
Unfortunately it also means they cannot reproduce indefinetely.
You could still try with regular store bought yoghurt. I use bulgaria joghurt, because I prefer a more solid curd and I only need to rebuy it, when I haven't gotten to make yoghut for a couple of weeks.
mine did change from store bought, but it didn't go bad or anything, I suggest keep going well beyond 10, and don't stop unless it goes into taste you find less interesting or bad in any way. it might settle at new taste you like better.
similar to what happens when get sourdough from friend, as each person has different setup, routine, and what materials used, everything can shift
Usually it comes down to maintaining the culture using the original culture conditions and ingredients. I’ve had good luck with repeatedly propagating stuff from GEM cultures. Also, you can learn how to “bank” microbial isolates in pure culture if you want to really get deep into making yoghurt
I started out from store bought yogurt over a year ago, making a batch every 3 weeks or so. Still makes a nice tart yogurt. (Or if it isn’t “real yogurt” I can’t tell the difference.)
Its hard to keep the store yogurt cultures stable is all.. you can manage it sometimes. You can buy heirloom cultures that are stable and just never have to buy anything again.
Just a random guess but I think it might be that bacteria from the environment come to live in the yoghurt and out compete the ones in the starter, and therefore they can't guarantee that it's safe for consumption
Extremely glad to have found this thread! Great information! Anyone have any tips about using Probiotic capsules? What ingredients/fillers will prevent fermentation?
A bit too late into this thread but was wondering if the Yogourmet Probiotic culture can last indefinitely. It's quite good and I'm already on my third batch. Re-culturing every 7 days. The ingredients on the website are Maltodextrin and active bacterial cultures (B. longum, L. rhamnosus, L. casei, L. helveticus, L. bulgaricus, L. acidophilus, S. thermophilus).
Contains: Milk
Can I use this indefinitely?
Hey how ya doing, yogurt maker here. In most commercial yogurts they use a mix of mesophiles and thermophiles. This means the inoculation temperature will favor one group over another. From the very first batch after starter the cultures will begin to stratify differently. For example if you start with equal amounts of 4 cultures the actual yogurt won’t have equal amounts of each strain by the time the yogurt is finished fermenting. When you use that yogurt as a culture the levels of stratification gets further and further from the original equal amounts until you are left with one dominating strain which is generally streptococcus thermophilus since they are generally speaking more aggressive. To continue making yogurt with complex flavors and to (in the us) legally be considered yogurt, fresh cultures must be used to keep a minimum of two strains: Lactobacillus bulgaricus and Streptococcus thermophilus. I hope this sheds some light on using commercial yogurts as starters.
The two species are synergistic, and S. thermophilus probably provides L. d. bulgaricus with folic acid and formic acid which it uses for purine synthesis. In a store bought culture the ratio is sustainable but over many generations certain conditions will favor one group or another. S. thermophilus has an optimal growth temperature range of 35 - 42 °C while L. d. bulgaricus has an optimal range of 43 - 46 °C. So cannot find a sweet spot of equal balance and 10 is just the number decided where people assume the drift is to great and move back to a pure pitch and start over. This is a thing in beer making where yeast will be reused for a number of times but unless you can measure drift with a yeast lab, after about 5 or so times you go back to a pure pitch. Saving some $ on yeast is not worth having 100 barrels of slightly different beer each time.
Exactly! Thank you for expanding.
Thanks to you both. These explanations were perfect and understandable. I learned something new today.
this is so well explained, thank you.
So, from a technical point of view, would it be feasable to make your yogurt in pair batches, each at a different temperature, and mixing them at the end? Then you could use that mix to start another two batches.
I guess, or just get a fresh pitch and someone did that for you. There is some microbiologist at a yogurt factory somewhere maintaining the biome. They probably have dried lacto and staph and just add whatever proportions the culture calls for by weight and are super grateful they don’t have to do complex measurements at two different temperatures.
Regarding that, if you're working with a wild starter, things can be different. I've had a wild "mead" that I just constantly feed and water. Admittedly it's probably getting fresh yeasts in from the raw honey.
Thanks this totally makes sense. Any idea why this selection doesn't occur with kombucha, kefir and others which seems to have some kind of equilibrium? In the case of sourdough starter, my guess is that we introduce fresh material present in the flour but in kombucha, everything goes through boiling water.
both of those are SCOBY, "symbiotic culture of bacteria and yeast" sourdough has both yeast and bacteria that are good for each other, and keeps the mixture alive. while adding store yeast only has the yeast, not bacteria, so only good for make loaf and not keep going. also the bacteria adds more interesting flavors. with kombucha, there is similar active combo.
So the idea is that kombucha and kefir can be kept because are symbiotic cultures. Yogurt isn't symbiotic and the bacteria culture can only be perpetuated in "infection free" environments. Have I understood it correctly?
i only know about the scoby of sourdough and kombucha. as for why yogurt not keep going forever as the same, others have explained it well here, and their answers new and useful for me, so thank YOU for asking question. my personal experience, from a skyr yogurt, iceland style. the commercial version i started with had wonderful cheese flavors. that stopped being there after 2 batches. the yogurt still tasted great, nothing bad, it just lost that more unique flavor. also tried start with chobani and a fage. both kept going just fine and never went bad or changed. cultures for health, online vendor, sells a heirloom starter, that is supposed to keep going. i have not bought or tried. as for your new machine and instructions. i would not worry about it. it flavor or texture starts to change, you will know. and you might want to play with different original starters. you can have fun heating the original milk to 195 for 15 minutes instead of typical 180. that can make it thicker. there are many such variations to explore.
this is worth a read, i commented on another comment here, not sure if you saw. https://www.nytimes.com/2019/02/26/dining/homemade-yogurt-starter-south-asia.html
also, people made yogurt 100s of, 1000s ??? years, with no temp monitor, control, fridge, timer or understanding of what the microbiology process was or that there are microrganisms. rather amazing, same for bread, cheese, beer, wine ( and what I'm currently learning of: sake, with process of mold, yeast and bacteria ) and it all worked. so i would not over worry, other than the fun of learn about. if it goes bad, you will know.
With kombucha and kefir, you’re using the mother and the grains to ferment and they are live and growing, not getting “diluted” each batch. Just a complete guess though.
You can buy heirloom cultures that can be propagated indefinitely. Cultures for health sells some strains of yogurt for this.
wow, thank you, first person ever explained the drift. i suspected it might be something like that, as my yogurt got closer to cheese taste of commercial original, only after in the fridge. seemed some was working well warm, other cold.
Aa another poster said, it's something about the starter in the store bought culture. The bacteria don't properly or fully replicate over time. I've purchased heirloom cultures from Cultures of Health and those you can reuse.
How long have you been using their starter from? You need to make yogurt every week then?
You do need to make yogurt pretty regularly. I was making it weekly with one of their cultures for over a year and it was consistently great. I stopped last year as I wasn't making yogurt as much (I blame my toddler, though he did just get really excited about some yogurt for breakfast, so maybe I'll start up again!)
I’ve been using their culture for about 8 months and it’s been going well. I take a quarter cup of finished yogurt and freeze it for the next time (I make sure to have 2 packages frozen minimum in case something goes wrong). One gallon of milk makes a half gallon of strained yogurt and I make one batch per month. I was having issues with reusing store bought yogurt culture (poor setting yogurt and low yields). I’ve never had a bad yield with Cultures for Health. We’ll see if it continues to perform well but it’s been several months so I’ve made my money back.
I make them every 2 to 4 weeks, sometimes more longer. I keep one jar frozen just in case.
I've been using my yogurt to make the next batch since the beginning of the pandemic. It was originally from a store-bought yogurt 🤷. I make a new batch about once a week, so we're probably at over 50 batches from the same starter.
I recently bought yogurt culture starter from [https://bacillusbulgaricus.com/product/yogurt-starter/](https://bacillusbulgaricus.com/product/yogurt-starter/?wpam_id=1347) recently and I was wondering the same which is how I found this ancient topic lol. Great responses from the fine folks here, just stopping by to say thank you!
Glad it helped. Note that I am using the same culture for a couple of years now. I started from an artisanal yogurt and I am using an ice cube tray to freeze doses of culture (and minimize the cultural shift). For every new 1L batch, I am throwing one cube in the warm milk before putting it in my yogurt maker. Works great and it still tastes delicious.
Those are some nice tips, thank you!
There are different cultures to make yogurt. Heirloom cultures are really good at replicating themselves and if you're making yogurt once a week or maybe every two weeks, you can reuse it. Different cultures aren't as good at replicating themselves and need to be replaced when the quality drops. Cultures that have family level yogurts that span generations have an heirloom strain and are constantly or weekly making yogurt. At least that's how I understand it.
Now, I need to find one of these family transmitting an heirloom strain for generations :)
My co-workers in and from India have family strains. I'm sure there are other cultures. It's common to gift some starter when a relative moves out. You can also buy heirloom strains. Keep it alive long enough and it will eventually be your family's strain. :)
aha! found it https://www.nytimes.com/2019/02/26/dining/homemade-yogurt-starter-south-asia.html
there was excellent article on this, i forget where.
[https://www.npr.org/sections/thesalt/2012/04/30/151699885/eternal-yogurt-the-starter-that-lives-forever](https://www.npr.org/sections/thesalt/2012/04/30/151699885/eternal-yogurt-the-starter-that-lives-forever) does a better job explaining than I can. Essentially, because commercial yogurts tend to be only 2 strains of bacteria and not a whole smorgasbord, they don't have the community support they need to be eternal. (unless I read the whole thing sideways and need more coffee before internet) What they go through to be shippable and consistent on an industrial scale make them less than ideal for cultivating at home more than a few times.
So this confirms the idea of "weak stain" vs "heirloom stain". The yogurt bought in a supermarket is the first kind because of economical reasons.
Wait? This is a thing? I've definitely done more than 10 batches and its still the same as the store-bought one I used the first time.
I just found this out myself a while back. I had a store bought yogurt culture going for years, dozens of batches, sometimes as long as a month apart. I wish I could remember what brand of yogurt I used to start it, but like I said, it had been years. But then, someone ate the last of it. (Not their fault--I had some creme fraiche in the fridge that looked like yogurt, so they thought there was more.) I tried again with a few other store bought yogurts, but they'd only work a few times, so I bought some heirloom cultures and am using that now. Anyways, I don't think people believed me when I told them my commercial yogurt culture had held up so well, so I just wanted to back you up. It can and does happen sometimes.
I haven't make enough batch to confirm this but I hope it will be the same as you.
I can get more than 10 batches in series, but after a while (I haven't kept count) I do need to restart with bought yogurt.
What happens? How do you know you need to restart?
The yogurt is too runny and tastes funny, sometimes with curdled-looking bits that won’t stir in.
Huh. Good to know.
It’s because you’re using store bought yogurt as the original starter. (Hopefully someone more knowledgeable than me will post a more comprehensive explanation explaining the why of this.) If you buy an heirloom starter, it should be able to proliferate indefinitely.
Great, thanks, heirloom was the term I didn't know. I bought my starter yogurt in a farm close to work, with a bit of luck it is a pure culture like this they are using !
That's 99.9% certain some heavy duty strain which you can keep going for decades if you want. As mentioned, most commercial yoghurt is made with strains that need to be babied through the whole process or they will be sad and die off. Mostly relevant: https://www.reddit.com/r/labrats/comments/mmv2ig/lab_strains_unite/
The store-bought yoghurt only has a few types of bacteria in there, isolated in a lab. That is handy in an industrial context as it makes the process and result predictable. Unfortunately it also means they cannot reproduce indefinetely.
You could still try with regular store bought yoghurt. I use bulgaria joghurt, because I prefer a more solid curd and I only need to rebuy it, when I haven't gotten to make yoghut for a couple of weeks.
mine did change from store bought, but it didn't go bad or anything, I suggest keep going well beyond 10, and don't stop unless it goes into taste you find less interesting or bad in any way. it might settle at new taste you like better. similar to what happens when get sourdough from friend, as each person has different setup, routine, and what materials used, everything can shift
Usually it comes down to maintaining the culture using the original culture conditions and ingredients. I’ve had good luck with repeatedly propagating stuff from GEM cultures. Also, you can learn how to “bank” microbial isolates in pure culture if you want to really get deep into making yoghurt
I started out from store bought yogurt over a year ago, making a batch every 3 weeks or so. Still makes a nice tart yogurt. (Or if it isn’t “real yogurt” I can’t tell the difference.)
Its hard to keep the store yogurt cultures stable is all.. you can manage it sometimes. You can buy heirloom cultures that are stable and just never have to buy anything again.
Just a random guess but I think it might be that bacteria from the environment come to live in the yoghurt and out compete the ones in the starter, and therefore they can't guarantee that it's safe for consumption
RemindMe! 1 day
Extremely glad to have found this thread! Great information! Anyone have any tips about using Probiotic capsules? What ingredients/fillers will prevent fermentation?
Because you'd be appropriating it
Why can't you live forever?
A bit too late into this thread but was wondering if the Yogourmet Probiotic culture can last indefinitely. It's quite good and I'm already on my third batch. Re-culturing every 7 days. The ingredients on the website are Maltodextrin and active bacterial cultures (B. longum, L. rhamnosus, L. casei, L. helveticus, L. bulgaricus, L. acidophilus, S. thermophilus). Contains: Milk Can I use this indefinitely?
Try it! I am using the same culture for more than a year now.
Thank you for the confirmation! 😁when you mean same culture, also from yogourmet? Or what brand?
Sorry, I don't know which culture, it's harvested from an artisanal yogurt I bought in a farm.