Danger in probiotic boosted home made yogurt ? - (Feb/20/2012 )
olothstar on Tue Feb 21 18:40:40 2012 said:
thanks for the reply. i guess my (and my GF, mainly!) main concern is solved : safe if the source of the strain is safe.
By "testing the yogurt" i mean like bring it to a lab, see which strains are in, and in what proportions. i'd be willing to pay some dollars, but nothing excessive. i'm curious what survives and what doesnt, and if its even worth doing the extra of adding the probiotics. The test i did (and will soon eat) was with probiotic pills (probaclac) which has 7 strains and 6 billions living cells, but i had the idea when i saw another product on the market which had 20 billion per serving or something silly. I just thought it couldnt hurt to add some strains to my homemade yogurt and get more benefits out of it.
Thanks again for everything said here, major help.
Its impossible to do what you want.. It will cost too much money, so I am afraid its not possible.
Unless you know someone who works in a microbiology lab and can help you a bit by plating them out, and buying a small identicication kit like API 20 but even then.. its still not that easy/cheap to do it.
(not that its that expensive either, but you just need to have acces to some lab/media and buy a kit like that)
yeah, thats what i thought.
i dont know anyone well enough to ask them to run that in their lab. the closest i got is someone working on cancer cells, so i dont see how we could spin it to make yogurt testing something he has to do in the day 
but i just got home, tasted the yogurt, and its great. had it in the incubator for a bit longer than i usually do, and its really thick and tangy. the taste is fine, although it does taste a bit different than the last batch, interestingly enough. I will keep on testing !
On this i thank this community again to put my fears aside of feeding probiotic-boosted yogurt to my family. I would also encourage everyone in doing their own yogurt. its good for you ! 
olothstar on Tue Feb 21 19:43:26 2012 said:
yeah, thats what i thought.
i dont know anyone well enough to ask them to run that in their lab. the closest i got is someone working on cancer cells, so i dont see how we could spin it to make yogurt testing something he has to do in the day
but i just got home, tasted the yogurt, and its great. had it in the incubator for a bit longer than i usually do, and its really thick and tangy. the taste is fine, although it does taste a bit different than the last batch, interestingly enough. I will keep on testing !
On this i thank this community again to put my fears aside of feeding probiotic-boosted yogurt to my family. I would also encourage everyone in doing their own yogurt. its good for you !
Just out of curiousity, but how do you make your yoghurt?
Its very straightfoward. Basically, take the best quality milk you can get, warm it up to about 140F (some bring it to a boil, i don't), and then let it cool to 115-118F. add powdered milk to increase the protein (thicker yogurt) and a tablespoon of a yogurt you like that has live cultures in it (non-pasteurized). mix well, then poor into mason jars or other clean containers and incubate 4-12h (depending how how thick and tangy you like your yogurt) at 99-118F.
for an incubator, personally i use a cheap egg incubator (hova-bator) because i do alot of incubation (yogurt, koji for miso and soy sauce, tempeh, etc), so it was easier, but you can use anything that will keep your temperature in that range for a long time. some ppl put it in the oven with just the light on, or the gas pilot on. some ppl use electric warming blankets type of thing. as long as it doesnt go over 118F !
i saw a nice Good Eats episode a few years back. found it for you on youtube. as usual, AB explains everything quite nicely.
http://www.youtube.com/watch?v=9PqQtdtcJtE
Everyone should make their own yogurt. i takes me about 5min every week to make enough for everyday use, and i never went back to store bought since.
Simon
olothstar on Tue Feb 21 15:12:50 2012 said:
about them being alive...the company claims that they are alive and well, at room temperature, until at least jan 2013.
I made a batch last night using one tablet (says it contains "6 billion active cells"), incubated over night. i'll try the results tonight. Wish i could test it easily see how many are now active in my yogurt, and which strains did survive the ordeal.
The bacteria in the pills or whatever form you have them in are probably not technically alive, they are much more likely to be in a spore form, which is kind of like a plant seed, a useful way of storing the bacteria until they reach the right conditions.
If you took each strain separately and grew them under ideal conditions, they are likely to divide roughly every half-hour - so if you started with 6 billion, half an hour later you should have about 12 billion and another half-hour later and you would have 24 billion...etc. In real life, this situation is a little bit unlikely to happen - you have other strains competing for the same limiting resources, which means that there are limits to how many bacteria will be produced, but you will still end up with many many times what you started with.
If you wanted to ensure that you can continue to culture your probiotics, you could probably start the culture as you would normally, add one of the pills and leave for a few hours. Then take the resulting product and put into small tubes and freeze, or spread onto tinfoil and dry (then freeze). This should preserve the cultures to act as starters for future cultures, meaning that you would have a supply for quite some time to come.
yes making your own yoghurt is really fun - especially when you have your own friut (puré), honey, nuts etc. to mix it with. Then you avoid the ecessive sugar and artifical aromatic compounds that are used in most commercial yoghurts!
And usually you simply use a spoon form any yoghurt as starter - meaning if you start with a greek style yoghurt or a probiotic yoghurt or a plain yoghurt from a local farm - all will taste different! You can also use differnt milk (goat, sheep) and get exciting tastes there! But I am talking about food again......so somebody needs to stop me or I will go on for ages 
However good luck with your experiments - and if you find an exciting mixture let us know!