YOGHURT – THE BASICS
Yoghurt making is fairly foolproof as long as you respect the fact that the yoghurt making process involves a living organism that is temperature sensitive – too hot and you kill it; too cold and it won’t work or multiply.
“The basic process is very simple: You sterilize the milk by heating it to a simmer, this kills all the existing bacteria in the milk so that it will only be fermented by the starter bacteria culture, which we add when the milk has cooled enough. We then keep it warm for 24 hours, by which time the starter culture multiplies and consumes all the [lactose/sugar in the] milk to produce our yoghurt.” (Quoted from here.)
For more information about SCD 24 hour yoghurt, including making goat’s milk yoghurt, and a couple of alternate methods ‘cooking’, you can visit this page. However, if you’re not on the Specific Carbohydrate Diet and you just want to make ‘normal’ yoghurt – see the bottom of this post under ‘Taking A Simpler Approach’.
- Volume = your desired amount of yoghurt. One litre of milk makes one litre of yoghurt.
- Maximum = as much as your ‘cooking’ container(s) will hold. If using a yogurt maker with a water bath – your maximum level is the top of the water bath.
- A note on milk type: The more fat the milk contains, the thicker and less tart the yoghurt will be.
You can use:
- Commercial yoghurt with active cultures from the supermarket. (Yoghurt culture is alive for up to 2 weeks after manufacturing). Use ¼ cup of bought yoghurt per litre (quart) of milk. Pay attention to the specific bacteria it contains, as these will be the strains in your yoghurt, eg. if you want one with Acidophilus etc.
FYI: the chinese names of the bacteria are…
保加利亚乳杆菌 bǎojiālìyàrǔgānjūn Lactobacillus Bulgaricus
– essential bacteria to make yoghurt
嗜热链球菌 shìrèliànqiújūn Streptococcus Thermophilus
– essential bacteria to make yoghurt
嗜酸乳杆菌 shìsuānrǔgānjūn Lactobacillus Acidophilus
– optional (but good for you)
A Note for those on the Specific Carbohydrate Diet….
There are other strains that are sometimes added to commercial yoghurt, but only these first two I’ve mentioned are essential to make yoghurt. All others are optional, but if you are following the Specific Carbohydrate Diet there is one rule – you should avoid all strains that start with ‘Bifid’. Also for SCD’ers, you should find a yoghurt that has no illegal additives like gums, carageenan, pectin etc. Low fat yoghurts are usually full of those things. You can read more about why these points are important at the official website of the Specific Carbohydrate Diet – http://www.breakingtheviciouscycle.info/
- The other option is you can buy freeze-dried yoghurt starter. I currently use Yogourmet which you can buy from here. I find this product yields a very consistent and flavoursome yoghurt. (Where I live in China, I could not buy any yoghurt products with the bacteria strains I wanted to use, so freeze dried is a better option for me. I also found freeze dried starter on Taobao (chinese eBay) when I was trying to find a supply of starter. In chinese I think they call it 酸奶菌粉 suānnǎijūnfěn = Yoghurt bacteria powder.)
- DO NOT USE your own home made yoghurt as the starter for your next batch. You might be able to get away with it occasionally (I have had to once or twice when I didn’t have any starter) but as a general rule – it’s a bad idea. It is inevitable that bad bacteria will be introduced to your starter yoghurt at some point (eg. the air around us is not sterile), and then when you incubate it in the milk for several hours – it will multiply – turning your yoghurt bad and ruining your whole batch.
HOW I MAKE MY ‘SCD’ 24 HOUR YOGHURT
- Rice cooker or similar
- Saucepan, glass jar(s) or similar, to sit in the water bath (inside the rice cooker) and hold the yoghurt while its ‘cooking’.
- PID Temperature Controller which keeps the rice cooker contents constantly between 38-42°C (100-110°F).
- Small bowl, stirring spoon and plate (to rest the stirring spoon on) – sterilised.
- If you will bring the milk to the boil in one pot/container and then transfer it to another one to ‘cook’ it, you must also sterilise that second ‘cooking’ container.
- Cooking thermometer (not essential).
1.) Put your desired amount of milk into a clean pot and heat slowly on a medium heat until the milk begins to simmer or reaches 82°C (180°F). Be careful because it can easily overflow in seconds.
*Stir the milk from time to time to keep the bottom from scorching, and again before you take a final temp reading to make sure that the entire contents have reached 180 degrees F. The purpose in heating the milk to this temperature is to kill any bacteria that might be present and interfere with the yoghurt making culture.
*Both cow milk and goat milk must be heated to just past 82°C (180°F), in order to sterilize them. However, cow milk can tolerate temperatures up to about 100°C (212°F), while goat milk is more delicate and should not be heated above 85°C (185°F).
2.) Turn the heat off and allow to cool to between 42-45°C (108-112°F). Stir well before determining the final temperature. You may cover the pot with a clean tea towel while it cools.
*You can speed up the cooling process by placing the pot in a sink of cold water. Be very careful not to splash anything into the now-sterile pot.
3.) Put your yoghurt starter in to the small sterilised bowl, add several tablespoons of the warm milk and mix it well until it seems well dissolved. Then add about half a cup more of the milk, mix well, and pour all of that back into the milk in the yoghurt container. Again, mix it well. Put the lid onto the yoghurt container, making sure it is secure.
5.) Put the yoghurt container, containing your milk and yoghurt culture into the rice cooker. Fill the surrounding space in the rice cooker with warm water to the appropriate mark (i.e. to the level of the milk or above, but not above the lid of the yoghurt container)
6.) Place the temperature sensor into the water bath and ensure its black top stays above the water. Plug the rice cooker into the power board. Plug the box of electronics (PID) into the power socket. Make a note of the time, and let it cook for 24 hours.
7.) After at least 24 hours, unplug the machine and remove the inner container. Carefully, (remember – it’s ALIVE), put the container into the fridge and let it rest for about 8 hours until it has cooled. Avoid bumping/jarring/mixing the yoghurt at this stage.
8.) After being refrigerated for 6-8 hours, gently but thoroughly, stir the yoghurt with a spoon or metal whisk to make it smooth. If you stir it too much it can separate, so remember to treat it gently. And that’s it! Enjoy your yoghurt! J
The bacteria in your yoghurt will survive for 2 weeks, and the yoghurt should be fine to eat for 3 weeks after being made. Anytime after 2 weeks though you don’t have the benefit of the bacteria anymore. We don’t find this a problem though because a 3.5 litre batch of yoghurt is lucky to last a week in our house before its all eaten.
(Recipe is basically taken from here.)
The box of electronics is sealed, with no bare wires these days. It’s difficult to see, but the saucepan is about an inch smaller than the inside of the rice cooker, and it also doesn’t touch the bottom (to prevent scorching). If you were using jars, you will need to elevate them somehow. The space between the saucepan and the rice cooker is filled with water, and the black cable is connected to a thermometer, which is part of the temperature control electronics.
You can also make yoghurt with totally non dairy milks, like almond or cashew milk. You can read more about this here.
TAKING A SIMPLER APPROACH….
If you decide that you just want to make yoghurt and you don’t care much about the lactose content or having the absolute maximum good bacteria volume etc, you can get away with being much less stressed about temperature accuracy, and still make yoghurt.
- Here’s an example of someone ‘cooking’ their yoghurt in a cooler/esky, with pitchers of hot water for warmth. Takes 6 hours they say.
- And here is a very clear step by step tutorial with pictures. This method requires a heating pad and they say it takes 7 hours, but you can choose to do it longer or shorter as desired.
- This page (under “Tips”) gives lots of different ways to incubate milk to make yoghurt.
Commercial Yoghurt is usually ‘cooked’ for 4.5 hours, which yields a sweeter yoghurt (still containing some lactose). The longer you ‘cook’ the yoghurt, the longer the bacteria have to eat the lactose(sugar) and multiply. So anywhere between 4.5 hours and 24 hours is an acceptable ‘cooking’ time, depending on your personal preference. As a general rule, the longer you ‘cook’ it, the more tart/less sweet, and thicker your yoghurt will be.
Please Note: This post is in no way replacing the wonderful information in the official SCD book ‘Breaking The Vicious Cycle’. I am simply showing how I make my SCD Yoghurt with the equipment I have available to me. If you are considering starting this diet, I highly recommend you first read the book. You can buy it here or here.