Author Topic: Yoghurt: best incubation temperatures?  (Read 1999 times)

Offline hippytea

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Yoghurt: best incubation temperatures?
« on: April 03, 2013, 04:41:46 AM »
Hi there.

I've been making yoghurt for a while, using full-fat pasteurised milk and a store-bought plain yoghurt as a starter (Rowan Glen low-fat, if that means anything - it's the only small pot my local shop sells). I've been having increasing success, tweaking the recipe this way and that as a result of tips found mainly on these forums. My method is now as follows:

- Heat milk on the stove to 86C. Maintain for 20-30min.
- Allow milk to cool in pan until it reaches 50C.
- Strain milk
- Divide starter yoghurt between two 1 litre plastic buckets (originally bought with yoghurt in them - really handy - they have handles and clip-on plastic lids)
- Add milk gradually to yoghurt, stirring, until tubs are full.
- Put tubs in slow cooker and fill slow cooker with water at target temperature. Put digital thermometer probe in one of the buckets, put lid on slow cooker and set to between 20 and 40W (I have a dimmer box made by a tame electrician - sadly you can't buy these).
- Culture for 7 hours. I do this during the day now so that I can glance at the thermometer readout every now and then and adjust the wattage to keep the temp within limits (I work from home).

 But one thing that is still puzzling me is incubation temperatures. The recipe I started with recommended 110F, which is 43C.

My first yoghurt attempts -culturing in the oven with the light on - were giving me very stringy, slimy yoghurt. Much Googling led me to guess that the temp was dropping in the course of the night, so the yog was culturing too cold.

So I came up with the slow cooker and thermometer approach. That allowed me to control the temps more closely, and there was a definite improvement - however, there was still a slight sliminess.

Then I noticed that the yoghurt recipe on cheeseforum.org recommends 50C as the incubation temp. So I tried that with my latest batch. The sliminess seems to have gone, and it is nice and firm, though I feel there is a slight "fragility" to the texture.

Is there one right answer to incubation temperature, or does it depend on the culture you're using? Since I'm working with store-bought youghurt as a starter, is this just something I'll have to experiment with?
« Last Edit: April 03, 2013, 04:48:11 AM by hippytea »

Offline Tiarella

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Re: Yoghurt: best incubation temperatures?
« Reply #1 on: April 03, 2013, 06:21:03 AM »
Welcome to the forum!   :D. As I don't make yoghurt I'm of no help to you with that.  Yoghurt seems so complicated once you've gotten used to making kefir.  Have you ever made kefir using what are known as "kefir grains"?  ( weird term since they are not grains but actually little colonies that look like rubbery pieces of cauliflower). Homemade kefir is very different than store-bought kefir and tastes quite like yoghurt but it's a zillion times easier to make and has more probiotic action.

Most kefir directions have you put your kefir grains in a jar, add the amount of milk that they can kefir in 24 hours and leave on the counter until the next day, then strain out the kefir grains and repeat in a fresh sterilized bottle.  Realizing that kefir was made by nomads without a dishwasher to sterilize bottles, etc, and being what you could either call lazy or extremely busy, I decided to assume there was an easier way so here's what I do:

I rarely wash my jar since I believe this was originally made in animal skin containers by peoples who poured out what they needed and then added the morning milking to the skin for the next day's kefir.  Each morning I pour out what I need (onto my granola) and then add more milk.  it sits on the counter unless I have so many kefir grains that they are turning it into kefir too fast at that temp in which case it goes into the fridge partway through the day.  (and then I eat a few kefir grains to get it back into balance). When I end up with too much kefir I make kefir cheese using the same technique one uses to make yoghurt cheese: ladle or pour it into tight-grained unbleached cotton muslin and hang to drain.  it's delicious plain, with fruit or blended with savory herbs and SO good for you!

Once in a while, or every day if I need to up my kefir production, I strain out the kefir grains and bottle the plain kefir and start fresh with the grains and milk in a clean jar.  (I do not sterilize because it's not necessary but I do wash my jars with hot soapy water just like the rest of the dishes.)

kefir can be thick or thin, mild and creamy or tart with a bite.  it's all about the ratio of milk to kefir grains and length of time before straining or using.  All the results are edible and tasty and the kefir grains are colonies of 34 micro-organisms so kefir is extremely health giving. 

No equipment needed, no temperature monitoring, so easy to make that you don't need to make a big batch...just a bit everyday in that easy "kefir rhythm".  kefir grains are usually available from someone locally or you can order them through the mail but make sure you are getting real kefir grains, not a powder that will make only a batch or two.  You cannot get kefir grains from store bought kefir or make it by adding kefir.....you really need those little kefir grains.

Hope I haven't bored you!   ;D. -Kathrin

Offline bbracken677

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Re: Yoghurt: best incubation temperatures?
« Reply #2 on: April 03, 2013, 09:57:19 AM »
I have incubated at 110 quite often, and then overnight held in the microwave with a container of hot water to maintain temp, but in the morning the temp has dropped to 80+/- (I just use the microwave as an insulator...A cooler with hot water would do just as well).  That works well for me.

What type of milk are you using? Non-fat, 2% or whole? I typically use whole and that results in a nice thick texture as well as flavor. You might also try changing milk supply to a different brand...

I also use a bulgarian yogurt as my starter...it only takes a couple of tablespoons or so for a half gallon of milk. I think I use like 1/4 cup when I make yogurt.

Offline hippytea

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Re: Yoghurt: best incubation temperatures?
« Reply #3 on: April 03, 2013, 11:30:07 AM »
What type of milk are you using?

Pasteurised whole milk. Co-Operative own brand, if that helps!

Offline bbracken677

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Re: Yoghurt: best incubation temperatures?
« Reply #4 on: April 03, 2013, 12:10:35 PM »
I like the texture from a whole milk better than a lesser fat milk, so yes...

I would suggest that you experiment with different milks to see if your texture issues can be helped with a different brand. Here in Dallas there is a huge choice of brands. I have narrowed my cheesemaking down to 3 brands when using HP milk.

Personally I have always used an incubation temp of 110F (43C) initially, but then when I let it sit overnight the temp drops down to upper 70s, lower 80s typically.  Once that is done, the next morning, I pour off the whey and then give it a good mix/stir before I transfer it to a glass container for storage.

One more thing...I make the yogurt in the original milk container, warming it in a water bath and then allowing it to slowly cool to incubation temp in the same container.

Offline Tomer1

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Re: Yoghurt: best incubation temperatures?
« Reply #5 on: April 03, 2013, 03:52:44 PM »
  (I just use the microwave as an insulator...A cooler with hot water would do just as well). 

Accually the microwave has very little insulation built into its double walls.

I use a deep fryer as an incubator. it ranges from 30c to 200c something and I marked 43c for thermo and 31 for messo. I fill it with water and put the glass\plastic container to incubate and cover it with a towel to minimize heat lose from the open lid.


I also like to mix some messo mix (anything which gives you a strong lactic set like FD) with the thermo for yogurt.  You can a less tart yogurt and better texture.

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Offline hippytea

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Re: Yoghurt: best incubation temperatures?
« Reply #6 on: April 04, 2013, 02:36:06 AM »
So does everyone here use 43C? Has anyone else tried 50C, as per the recipe on the main site?

It did seem quite hot to me, but I thought it was worth a try. It has set well but is a little inclined to break up into grains.

I will try different milk brands as suggested. However, I may have overstated my texture problems - at first the sliminess was noticeable to everyone, when I got the temp sorted out it became slight so that only I noticed. The breaking-up I'm getting now is also slight and could probably be sorted by draining some of the whey.

In other words, I'm being fussy. But I am curious about this temperature thing.

Offline bbracken677

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Re: Yoghurt: best incubation temperatures?
« Reply #7 on: April 04, 2013, 07:07:08 AM »
This is the process I use...  As part of my process there is a link to Sailor's method for making motherculture. His treatise of making motherculture is great learning.

http://cheeseforum.org/forum/index.php/topic,10336.0.html

Offline hippytea

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Re: Yoghurt: best incubation temperatures?
« Reply #8 on: April 11, 2013, 07:38:54 AM »
Thanks for your replies everyone!

Offline Johan Ainslie

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Re: Yoghurt: best incubation temperatures?
« Reply #9 on: April 12, 2013, 01:01:35 PM »
When using store bought joghurt for a starter I inoculate at between 45 and 47C. I get a very nice texture and little whey. When using a commercial culture I inoculate at 42C and add skimmed milk powder at 4% which gives me a thick porcelain look joghurt with a very nice taste.
I might also add I try to keep the incubation temp as close as possible to the temp at which inoculation took place by using a coolerbox which I fill with hot water at the desired temp. Incubation is usually 4 hours.
« Last Edit: April 12, 2013, 09:00:07 PM by Johan Ainslie »

Offline Brandnetel

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Re: Yoghurt: best incubation temperatures?
« Reply #10 on: May 25, 2015, 12:26:21 PM »
Hi folks!

Sorry, it has been a while since I posted here. Have not made cheese for a while (since an unfortunate fridge accident!) but we tried making yogurt this weekend. One quart full-fat homogenized organic cow's milk, one quart goat's milk in separate batches.

As a started we bought some "Bulgarian" yogurt with active cultures. But due to looking around at generic homemade yogurt instructions, we just raised the milk to 180 degress, then lowered to 110-115 and added in the yogurt. We then kept in the unheated oven which was in the 80s-90s overnight. In the AM I was disappointed to see the milk was not set, but reading further I saw that 110-115 is really needed to activate thermophilic cultures in particular. And upon further research it seems like the traditional Bulgarian culture is thermo looking for example at this:

http://www.culturesforhealth.com/bulgarian-yogurt-starter.html

So, undeterred, I bumped my oven on a couple of times and have kept it in the 110-115 range substantially for maybe 2-3 hours. And it looks like at least the cow's milk has set! So we'll see how it goes. Would appreciate any thoughts or feedback the group might have.


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Offline Stinky

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Re: Yoghurt: best incubation temperatures?
« Reply #11 on: May 25, 2015, 01:39:02 PM »
Don't heat the milk that high. It's only necessary to do that if your milk is raw and you don't trust it. Even then, you would only want to keep it at that temperature for a matter of second, and I doubt you have the equipment for that. If your milk needs it, try 140º for 30 minutes or so, but you shouldn't have to do that part. It might have caused the result, although I doubt it.
It's probably a pathogen.

Offline awakephd

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Re: Yoghurt: best incubation temperatures?
« Reply #12 on: May 25, 2015, 09:21:12 PM »
Hmmm, I don't think heating the milk to 180° is for the sake of pasteurization (though it does accomplish that as well, of course). Rather, my understanding is that it has to do with changing the whey proteins (like with ricotta) so that the resulting yogurt is thicker. I heat my milk to 180° and hold it there for 30 minutes, stirring constantly, and get the most amazingly thick yogurt.

One other key for me is that once I am done incubating the yogurt, I put it straight into the fridge without disturbing it. If you mix or strain it while still warm, it will tend to break up. If you chill it first, it sets up thick, and then you can strain it if you want -- but you might not need to, since it is already so thick!
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Offline Brandnetel

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Re: Yoghurt: best incubation temperatures?
« Reply #13 on: June 01, 2015, 10:41:34 PM »
Thanks, folks. Will keep your thought in mind for the next go-round. I did do maybe a bit much stirring during the heating process.

The cows-milk batch turned out pretty good, not as quite firm as I would like but credibly yogurty in texture with a nice tang.

The goats-milk was barely thickened after its overnight incubation, so I bumped the oven again and left it until evening. Didn't thicken up much more, rather soupy but a nice taste with a lemony edge. Over a few days I thought the goatiness began to come out some.

After chilling, we took half of each batch and strained it overnight to try to make something resembling labneh. Here are some pics of the cow version, which came out the best with a nice cream cheese-like texture.



We dosed it with some olive oil and home-made za'atar spice blend and ate it on toasted pita. Mmmm.



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Offline Mermaid

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Re: Yoghurt: best incubation temperatures?
« Reply #14 on: June 02, 2015, 07:09:40 AM »
I culture the yogurt at 110 F and hold it at 106-108 for 6 hours- then cool it down to 40 F. I use a refrigerator that has a baseboard heating element in it. So I turn off the fridge and turn on the heater. Wait until it's at 106, then load in the yogurts. When I'm ready to cool down I unplug the heating element and plug the fridge back in.