Author Topic: Copying probiotic yoghurt  (Read 2078 times)

Offline Zoey

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Copying probiotic yoghurt
« on: April 23, 2012, 01:26:51 AM »
I'm trying to shift our family to use only self-made dairy products. The yoghurt making part of it is mainly a cost issue, since my hubby likes to eat these probiotic things that cost us 2-4 euros per day.

Anyway, I tried making the same stuff by taking one portion (120g) of yoghurt, putting it in a glass jar with 1 liter milk. Warmed to 50 Celsius in a pan, moved to incubate in the oven for 6 -8- 12 - 24 hours. Nothing happened. I've used the same method with bulk bulgarian yoghurt before and it has always worked.

So my troubleshooting begins:

 - Since it is advertised as probiotic, it has to be a live culture, right? Otherwise the culture wouldn't do anyting in the eater's stomach either?

 - The bulgarian yoghurt I have used before, has been drained. I've only used a spoonful, but I'm still thinking maybe this non-drained stuff is not as effective (bacteria count less?) - but it should be possible, right?

 - Could different strains of bacteria have different incubation temperatures? Maybe my 50 Celsius was wrong, even it works with bulk yoghurt?

- Maybe the manufacturer has done something to prevent copying of their products?

Any thoughts apprecciated. The yoghurt I'm trying to replicate is this:
http://en.wikipedia.org/wiki/Activia

Best regards,
Maria

Offline Zoey

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Re: Copying probiotic yoghurt
« Reply #1 on: April 23, 2012, 01:36:46 AM »

A little addition...

I read this: http://cheeseforum.org/forum/index.php/topic,4694.0.html

So if I understand correctly, if I succeed to make it coagulate, I have to worry about the acid not killing off my bacteria as well, since otherwise it wouldn't work as probiotic anymore?

By the way, I don't really know if the probiotic bacteria have any real effects. But since it's important for hubby, I'm playing along.

Offline linuxboy

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Re: Copying probiotic yoghurt
« Reply #2 on: April 23, 2012, 02:14:36 AM »
User lower temp. For Activia, try 41-42C. And after leaving the milk in, check the temp. Stove might be heating it too much. Also, when you add in the yogurt, temper it. Mix with some of the milk first to thin it out, and then mix with the rest of the milk.

Quote
- Since it is advertised as probiotic, it has to be a live culture, right? Otherwise the culture wouldn't do anyting in the eater's stomach either?
Yes, although it might be old and the bacteria may have died.
Quote
- The bulgarian yoghurt I have used before, has been drained. I've only used a spoonful, but I'm still thinking maybe this non-drained stuff is not as effective (bacteria count less?) - but it should be possible, right?
Yes, should be possible.
Quote
- Could different strains of bacteria have different incubation temperatures? Maybe my 50 Celsius was wrong, even it works with bulk yoghurt?
Yes, they do have different ideal temps. 50C is too high.
Quote
- Maybe the manufacturer has done something to prevent copying of their products?
In the sense that strains are patented, yes. In the sense that it would cause the milk to not coagulate, no.

Quote
So if I understand correctly, if I succeed to make it coagulate, I have to worry about the acid not killing off my bacteria as well, since otherwise it wouldn't work as probiotic anymore?
Correct, same as Dannon and other manufacturers. Bacteria do die off over time.
Quote
By the way, I don't really know if the probiotic bacteria have any real effects.
yes, they do. Helps to boost immune function, among other benefits.
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Offline Zoey

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Re: Copying probiotic yoghurt
« Reply #3 on: April 23, 2012, 05:58:17 AM »
Whow, thanks linuxboy, that was really helpful. It seems you know all about this subject. :)

I will try all your tips and report back.

Offline DeejayDebi

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Re: Copying probiotic yoghurt
« Reply #4 on: April 23, 2012, 08:19:56 PM »
Hi Zoey -

Some cheese suppliers sell a yogurt culture with and without probiotics. Here is an example of what you might be looking for. I find using the cultures makes a far better yogurt > then better starter for the next batch than store bought ones. Maybe they are just dead like Linixboy suggested?

Offline Zoey

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Re: Copying probiotic yoghurt
« Reply #5 on: April 25, 2012, 01:52:19 PM »

I lowered the temperature and now it coagulates. Yippee!

However, it turns out super-grainy, almost like curds & whey. I wonder why... I only incubated for about 5 hours, although now I regret that I didn't check it earlier, this may be due to overincubation, or not?

The super-grainy stuff still doesn't seem very thick, but then again, the separated curds cannot be properly compared to creamy yoghurt...

I'm thinking of trying two things:

1. trying to control the temperature even better: I would think that curd separation would be due to too high temperature, rather than too low? I'm afraid my yoghurt might have gone up to 45 celsius, even I was aiming for 42. After all, my oven isn't that precise and I had to turn the temperature up and down all the time to keep between 40-45.
2. adding a bit of powdered milk for thickness. Maybe this would help me achieve the proper thickness before it gets too sour and separates the curds? although it didn't taste super-sour, and as I said, it was only 5 hours. but still. at least it could help the thickness issue.

Oh, and I forgot to say in the beginning that I heat it to 185 celsius for 20mins at first. Although almost every time I mess that up and boil it at some point.

Offline Tomer1

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Re: Copying probiotic yoghurt
« Reply #6 on: April 25, 2012, 02:21:05 PM »
Did you stir your starter\yogurt well into the warm milk before adding to the entire batch?
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Offline MrsKK

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Re: Copying probiotic yoghurt
« Reply #7 on: April 25, 2012, 05:07:40 PM »
You really need to control temperatures better to get good, consistent yogurt.  When heating your milk, you can do that by using a double-boiler system by putting one kettle inside a larger one and filling the outer kettle with water.  During the incubation, you can put a good-sealing jar inside a cooler filled with hot tap water.  Don't open it during the incubation period, which should be 8-10 hours.

I use one cup of store-bought Greek yogurt to one gallon of milk and get very good results.  If you use more than that, it may have been over-cultured.

Are you sure you heated your milk to 185 celcius?  That's 365 degrees Fahrenheit and is way over boiling point, which is 212 Fahrenheit.  100 Celcius is boiling point. 

I get good consistent results when heating to 185 Fahrenheit, which is 85 Celcius. 

Offline Zoey

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Re: Copying probiotic yoghurt
« Reply #8 on: April 26, 2012, 12:29:04 AM »
Karen,

You are right, it was 85, not 185. :)

Ok, so three things to try would be:

- more even temperature
- better mixing of starter (i have used a whisk and I think I've mixed thoroughly but I can always give it some extra attention)
- less starter

If I've understood correctly, a gallon can mean three different measurements? So I'm not sure how much one cup per gallon is. Something like 1/15 or 1/20? I use liters / deciliters myself. But since I use one package of 100g per one liter, it's clearly more, around 1/10. I'm sure the right amount also depends on the brand you're using. I figured that since mine is not drained (greek usually is?) I should use more. But I'll try with less and see what happens. I guess this is just about experimenting until I get it right...

Offline MrsKK

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Re: Copying probiotic yoghurt
« Reply #9 on: April 27, 2012, 05:39:01 PM »
One cup per gallon would be 1/16, so you're using a bit more than necessary.  I use the same amount, whether drained or not.

I get the smoothest, creamiest yogurt when I heat my milk to 185 Fahrenheit, allow it to sit at that temp for 20 minutes, then let it sit at room temp until the milk gets down to between 110-115 degrees Fahrenheit.  I used to quick cool my milk in a sink of cold water, but had something going on once that meant the slower cooling and I got much better results, so that's how I do it all the time now.

I whisk my starter yogurt until it is smooth, then whisk in enough warm milk to make it pourable.  Then whisk it into the milk.  So a lot of whisking, but it prevents clumps of culture sitting in the bottom of the container, too.

I think that getting your incubation temperatures under control is probably the biggest thing you can do to improve your results.  Cultures don't like up and down temps - go too low and you slow down the growth rate, go too high and you kill off some or all of the organisms.

Offline Zoey

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Re: Copying probiotic yoghurt
« Reply #10 on: May 25, 2012, 12:47:06 PM »
Thanks everyone, I've got it under control now. Here's what I did:

- I mix the yoghurt with just a little milk first, then add milk little by little until everything is mixed. So at least it should be very well mixed now. I read something about heat shock as well, so maybe this eases the transition from cold yoghurt to warm milk a bit.

- I mix at 43 Celsius, then put it under the oven lamp which is around 37-38 Celsius for about 5 hours. It seems that the even 37-38 is better than an uneven 40-45. Maybe a little too low is better than even a moment of too high. Understandable...

- I've tried holding 20 mins at 85 Celsius and also just heating to 90 Celsius and letting it cool without holding the 20mins. I've noticed no difference.

- I've tried with 2 spoons of powdered milk per liter, 1 dl per liter and without any. It seems that the 1dl is way too much, but 2 spoons may be pretty optimal. But not necessary at all when the other steps are done well.

Hopefully this report helps the next one that has similar trouble.

Offline MrsKK

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Re: Copying probiotic yoghurt
« Reply #11 on: May 25, 2012, 05:06:42 PM »
So you are getting good, thick, creamy yogurt now?  I'm glad you were able to work your way through it.  Great job and a cheese for you!

Offline DeejayDebi

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Re: Copying probiotic yoghurt
« Reply #12 on: May 25, 2012, 07:41:13 PM »
I just made 2 gallons of yogurt and tried the yogurt culture from Dairy Connections. Man that stuff is great! I can only get plain here in the large jugs ($4 each) and most goes to waste so I figured what the hey? Bought some store bought milk (not Jersey milk from the farmer), Hood I think and tested it out. Put the powder in my little 1/4 cup cheese cup in water while I got the milk up to temperature and could see it grow before I was ready to use it! Put it in my oven out of drafts and went to bed. Took it out after work and was really impressed! There's no whey at all that I can see and look how thick it is ... it doesn't even fall off the spoon when here straight up!




Mixed up some  mango, straberrry and blueberry and left the rest plain for now.




Offline Tomer1

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Re: Copying probiotic yoghurt
« Reply #13 on: May 25, 2012, 08:02:30 PM »
I prefer to make a large batch of yogurt and have my fruit additions made seperatly.  The two alone (unmixed) have much longer shelf life without the need of perservatives like pottasium sorbate.
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Offline DeejayDebi

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Re: Copying probiotic yoghurt
« Reply #14 on: May 25, 2012, 08:12:05 PM »
I never add anything but well ripened fruit to my yogurt except for blueberry I add about 1 teaspoon of honey as the berries are sometimes very tart and peach and apple I like cinnamon . Yogurt never lasts more than a week in my house. I take a quart to work everyday and share it with a friend and it's gone by lunch! The second gallon stays home and is gone in a week.