Yogurt comes in plastic pots  and I of course refuse to use one use disposables. So the pots have to go,but who can live without yogurt? Not us, so I had to learn how to make my own.

I had heard of how you could make it in a flask but I just ended up with curds and whey and an evil-smelling flask. Then Husband remembered how they used to make it back in the village  of his birth. He ended up with curds and whey and evil-smelling blankets.

So I bought me an Easy Yo Yogurt maker – – really easy – just mix the contents of the sachet with water – yes that’s right – the plastic foil sachet that came in the plastic packed box. Didnt think it through. Not best pleased – it did make very good yogurt though. If only they sold the mix in a jar – or cardboard box. Ho hum back to the drawing board.

And maybe it might be worth doing some in depth research:

So What Is Yogurt

Milk like everything else is full of bacteria. Even pasteurised milk as pasteurisation only kills a certain percentage of bacteria in milk. After a time these bacteria start to multiply. Some bacteria cause milk to go bad, others can turn it to yoghurt. Depending on which gains the upper hand, the end result can be evil smelling gunk or a tasty snack.

The main (starter) cultures or bacteria needed to turn milk into yogurt are Lactobacillus bulgaricus and Streptococcus thermophilus.

These are used to ferment the lactose (milk sugar) in milk. This results in lactic acid which decreases the pH, and breaks down the cell membranes so the proteins clump together and form the soft gel or as we know it, yoghurt.
Yoghurt is actually a very soft cheese.

If the yoghurt making bacteria are dominant they multiply and consume the food supply (milk sugars) starving out other bacteria, including the type that makes milk go off

Traditional yogurt has a high acid content, which many bacteria cannot survive in which is another reason yogurt stays fresh longer than milk.

Making Yogurt

The yoghurt making process is one of favouring certain bacterias over the others. This is done by killing off existing bacteria, introducing yogurt making bacteria, the starter culture, then ensuring that conditions suit the growth of that bacteria.

You will need…

milk 1 liter
starter culture (bacteria) 3 tablespoons of live yogurt or a powdered starter – see below for more details
a way to heat the milk
a food thermometer
A container for your yoghurt.
a way to keep the yogurt at a warm and constant temperature.

Chose your Milk
To make yoghurt you need milk proteins and milk sugars – milk in other words. But which milk?
I use Pasteurized milk from the milk man. Check out this list of people who deliver milk in glass bottles.
Ultra-pasteurized is said to be too sterile(I don’t know why that matters if you are introducing the culture), raw milk I don’t work with.
The milk can be whole or reduced-fat.
Or a mixture of the two.
Adding dry milk powder will increase the amount of whey protein and create a richer textured yogurt. See where you can buy loose powdered milk here.
Cream apparently doesn’t work at all.

Pasteurize the Milk
The milk mixture needs to be heated to 185°F (85°C) for 30 minutes or at 203°F (95°C) for 10 minutes. Which means you warm the milk to just below boiling on the stove, maintain the temperature keeping an eye on it all the while.
Some recipes say for half an hour though many say less time is needed.
This serves 2 functions:
First it breaks down the milk proteins resulting in a more stable yoghurt
Secondly it kills off any unwanted bacteria already present in the milk.
N.B. Even Pasteurization of milk only kills a certain percentage of bacteria in milk.

Cool Milk
Put the milk into your containers.
Allow the milk is cool to 108°F (42°C) the ideal growth temperature for the yoghurt making bacteria, (starter culture).

Add bacteria
Now add your Starter Culture. This usually a dollop of live yogurt though you can buy starter culture in other forms. more on this below.

Mix well

Allow To Ferment
The mixture now has be kept at 108°F (42°C) until a pH 4.5 is reached allowing fermentation to take place. Fermentation results in the soft gel known as yogurt. This process can take several hours. Too hot or too cold and your bacteria won’t work.
You have to find a reliable way to keep your mixture warm and at a stable temperature.

Ways to keep warm
an electric yogurt maker,
an insulated container or flask
an oven with just the light
a food dehydrator
Lots of blankets

To check the yogurt is ready, try tilting the pot. If it moves as one you have made yogurt.Yay. If it separates into liquid and solids the bacteria has run out of food.

The longer you let your yoghurt ferment the more acid it becomes and the more tart the taste.

Cool
To stop the fermentation process cool the mixture to 7°C.

Starter Cultures

The yogurt starter can be made from live yogurt bought from a shop. make sure it says “live cultures.
You can  use your own homemade live yogurt as a starter culture.
You can buy starter cultures as a powder. These are from Amazon. Obviously the packaging contains some plastic but so does a pot of yogurt.

Trouble Shooting

Theoretically you should be able to use your own home made live yoghurt to make more yoghurt indefinitely However we find that after a while our home made live yoghurt seems to loose its strength and we cannot make more using this batch. So every few weeks we need to buy a new container of yogurt for a fresh culture.

This is because the bacteria is weak, possibly dead

One solution is the freeze a fresh batch as soon as the yogurt is made. This keeps your bacteria feisty.

Keeping it warm. If you dont have a constant heat source,  yogurt making can be tricky. I tried putting it in the oven and making it in a flask but the results were too variable. finally got me an electric yogurt maker from Lakeland – mail order. The yogurt is made in a plastic container -BPA free for those of you worried about leaching chemicals. It works really well. So although it is a plastic product I feel it is worth it as it cuts our overall plastic consumption. It does make good yogurt and is very easy to use. If you are busy I would recommend getting one of these.

Update

Trying Homemade Again Since then VB has re-learnt his yogurt making skills and now makes it in a pan which he leaves wrapped in a blanket overnight. Completely plastic free.

Reusing the Easy Yo And if you check the comments you will find out how to make yogurt using hot water and how to use the Easy Yo yogurt maker without purchasing more sachets.

More

Lactobacillus bulgaricus and Streptococcus thermophilus are the only 2 cultures required by law  to be present in live yogurt.
Lactobacillus acidophilus, Lactobacillus subsp. casei, and Bifido-bacteria are probiotic cultures. These, it is claimed, help improve  lactose digestion, gastrointestinal function, and stimulate the immune system.

There are yogurts that culture at room temperature, which is even easier!

Find other plasticfree recipes here.