How to make Yoghurt

My latest batch of homemade yoghurt

Making yoghurt is one of the simplest things you will ever do. Trust me.

If you have a large family that loves the stuff, it will also be one of the most frugal things you ever do. Indeed, once you’ve got the process down, you can start getting them to take over from you.

The key to all of this is to remember that yoghurt has been around since the Stone Age.

It’s not complicated.

My latest batch of homemade yoghurt

My latest batch of homemade yoghurt

Mind you, there’s a few things we do for safety now, that weren’t done then – and our implements look a little different – but it’s still pretty much the same. All of which means that it’s pretty much idiot-proof.

To make yoghurt, you will need milk (cow’s milk, goat’s milk, soy milk) and either culture or starter. This post will use starter.

Find a plain yoghurt you like and that can be your starter. Hard, isn’t it?

Okay, I’ve been told to be more serious. Ahem.

All yoghurts contain bacteria which have digested the natural sugars in the milk and helped to transform the proteins. (For more detail read Yoghurt 101.) When you decide that you wish to try making this all happen under your roof, you’ll need to start by getting yourself some yoghurt.

In the chiller section of the supermarket you will find myriad yoghurts ranging from low-fat to sugar-free and everything in between. What you need to look for is a small tub of natural yoghurt.

When you find one, look at the ingredients label. It should contain nothing more than milk, milk products and cultures.

Greek yoghurt label

Greek yoghurt label

If your label says live cultures, then that’s even better.

You don’t need anything that has stabilisers or food numbers on it. Those ingredients are used to thicken the final result. They often do not have the required numbers of bacteria in them and, if you were to use that product as your starter, you would end up with something that resembles cultured buttermilk and you would hate me forever. Don’t do that.

See the additives. Avoid. The blurring is the label, not my photography...

See the additives. Avoid. The blurring is the label, not my photography…

Also, be aware that Greek yoghurt is not only a type but is also a method of making yoghurt. Use it as your starter by all means, but it will not set firmly. If you prefer the taste of Greek yoghurts to those formed with L.acidophilus then make your yoghurt from it, but know that it will require straining to achieve the firmness of the yoghurt in the tub you have purchased.

This isn’t at all difficult, but you may wish to try something that will give setting satisfaction first. 😉

If you find locating something this simple and unadulterated difficult to do, then try using a packet mix yoghurt for your first shot and putting aside some of that as your starter. Be pragmatic.

Packet yoghurt mixes can be handy but not terribly economical...

Packet yoghurt mixes can be handy but not terribly economical…

As an aside, there is nothing intrinsically wrong with using powdered mixes like these. Just be aware that they also use stabilisers – which can exacerbate some allergies. Also, there is no budgetary advantage to doing so. A packet of yoghurt mix costs around AUD$4.50 as does a litre of yoghurt at the supermarket. A litre of milk costs $1 or so. If you have several children eating several kilograms of yoghurt a week, making your own from scratch is much more economical.

Yoghurt will last for quite some time when properly stored in a refrigerator, but you need your starter to be relatively fresh so check the dates on any fresh yoghurt you may buy.

Next, you will need to get your milk and equipment all in the one place.

You will need:

  • a large saucepan or pyrex jug,
  • a thermometer (or your clean finger),
  • a small bowl,
  • a dessertspoon,
  • a whisk or fork,
  • a large bowl or covered container,
  • something to keep your yoghurt warm in.

Make sure everything is as clean as possible. The only bacteria you want to grow is that in the yoghurt culture.

Now, heat your milk. If it is raw milk it is safest to bring it to a boil (at least 85°C or 180°F) and then let it cool to the desired temperature. If you do this on the stove top, use a large saucepan and watch it carefully to avoid having the milk boil over.

Otherwise, you can heat your already pasteurised milk in the microwave using a large Pyrex jug – which is my preferred method.

I heat my yoghurt in the microwave, using a large pyrex jug.

I heat my yoghurt in the microwave, using a large pyrex jug.

It’s much easier to wash up the jug, I find, and then pouring it into the container in which I want it to ferment is much easier than pouring it from a saucepan. One litre of milk straight out of the refrigerator needs only 3-4 minutes on HIGH in my microwave and then I can place it on my counter and wait for it to cool down.

Allow your milk to cool to between 47°C (116°F) and 32°C (90°F). You can use a thermometer to test this or wash your hands and use a finger – since the Stone Ages, remember? – dip in a finger and count to ten, the milk will feel uncomfortably hot, but bearable.

This is important. Yoghurt bacteria are like yeast.  Too hot and the bacteria will die, too cold and they will remain dormant.

While you are waiting for your milk to cool, place two dessertspoons of your starter culture into a small bowl. A good rule of thumb is one dessertspoonful (2 teaspoons) of starter for each 500ml of milk.

Pace your starter culture into a small clean bowl.

Pace your starter culture into a small clean bowl.

Then, when your milk has cooled sufficiently, place half a cup or so into the bowl and whisk well.

You want the result to be quite smooth.

Blend your culture thoroughly into a small amount of warmed milk.

Blend your culture thoroughly into a small amount of warmed milk.

It won’t break, there’s no need to be delicate.

Blend well.

Blend well.

Now reintroduce the liquid in the bowl to the rest of the warmed milk, again blending well.

Introduce your culture mix to the rest of the milk and blend well.

Introduce your culture mix to the rest of the milk and blend well.

You’re pretty much done. Now all you need to do is maintain the temperature for 6 to 8 hours. My mother used to put the mix in a bowl with its own lid, wrap it in a towel and place in on the internal water heater overnight. I know some people swear by placing their yoghurt into an oven with just the pilot light on.

You could place it into a thermos or vacuum flask.

Some place their heated milk into a preheated crockpot or slowcooker. To do this preheat your slow cooker on High but switch it off when you add your yoghurt mixture and then wrap the whole thing in a towel overnight.

You could place your sealed container into a foam insulated box, esky, cooler box or chilly bin with a filled hot water bottle for company.

I use a commercial yoghurt making device that is a simple, plastic-covered foam flask.

The yoghurt 'flask'

The yoghurt ‘flask’

I place my yoghurt mix into a plastic container with a screwtop lid, half fill the flask with boiling water, pop the container in, put on the lid of the flask and leave it overnight.

You simply half fill it with boiling water.

You simply half fill it with boiling water.

Add boiling water and then your yoghurt mixture.

Add boiling water and then your yoghurt mixture.

I like using this because it’s so convenient. Firstly, I can simply take the set yoghurt out in the morning, wipe off the container and put it in the fridge as it is. Secondly, the flask itself takes up very little room and can be popped in a corner, on the dining table or anywhere else with very little trouble.

I will be offering one of these in a competition for my readers in the next few days.

I also like not having large containers of warm liquid to juggle (and most likely spill everywhere).

It is far better to make smaller amounts of yoghurt often, rather than large amounts infrequently. Your yoghurt depends on the freshness of the starter culture so, if you keep your own stocks ticking over, you will be able to continue using your own yoghurt as a starter for longer.

It’s also easier to cope with a litre or two at a time in your refrigerator than it is to cope with a gallon of it. Trust me.

Make up your yoghurt of an evening and it will be ready for the refrigerator first thing in the morning. Try not to leave it to ferment for any longer or it will become quite sour. Go about your day and let it set – leave it alone.

That evening it will be ready for you to strain off the whey, divide for portable lunches or breakfasts, flavour or use in other recipes.

Just remember to put a few spoonfuls aside to start off your next batch!

You may wish to enrich your yoghurt with milk powder or cream. This isn’t necessary, but it can give you a much firmer yoghurt. I shall include instructions for how to do this in the recipe below, but plain old milk is fine. 🙂

I will be posting a few ideas for how to use your yoghurt in the near future.

How to make Yoghurt

Ingredients

I litre fresh milk

¼ cup skim or full cream milk powder

1-2 tablespoons fresh commercial yoghurt

Method

Rinse all equipment in boiling water to sterilise.

Heat-proof glass mason jars with loose fitting lids are ideal for incubating and storing your yoghurt.

Pour  milk into a saucepan and then blend in the powdered milk until thoroughly dissolved.

Bring gently to a boil.

Remove from the heat and allow to cool until tepid – 45°C.

Place your culture into a small bowl and add ½ a cup of your cooled milk. Blend well with a fork or a whisk.

Reintroduce this mixture to the rest of your heated milk. Again, stir well.

Pour the culture mix into an incubating container and keep warm for at least 6 hours.

Do not disturb your yoghurt while it is setting!

When the yoghurt is set it will have a thin layer of clear, yellowish liquid surrounding it. This is whey and is perfectly normal (and edible).

Place your containers into the refrigerator to cool and set more firmly.

When you wish to eat the yoghurt, you may stir in the whey (it is high in protein) or strain.

Reserve several tablespoons of your yoghurt to act as your starter in your next batch.

Looking for things to make with your yoghurt? Try these:

Frozen yoghurt

 

Yoghurt 101

A Potted (Yoghurt) History

Yoghurt is a food that has been with us for millennia – at least since we started collecting milk from animals and storing it for any length of time.

It’s a foodstuff that started out big in Central Asian cultures back in the Neolithic (ah, the good old days!) and which has really only spread into the Western world since the 1900s.

I know. Weird, eh?

Coz it feels like it’s always just been a thing.

Basically, someone (somewhere) kept some milk at a warm enough temperature that the bacteria it carried started to multiply and change the proteins of the milk. They then tasted it and decided it was good.

They were right.

Make your own yoghurt in next to no time.

Make your own yoghurt in next to no time.

What is yoghurt?

It’s highly nutritious and endlessly delicious. High in protein, tolerated well by people who may usually have difficulties with ingesting dairy products and full of microbes that may help a gut worn down by living and digesting in the modern world.

That last bit, my friends, means that eating yoghurt can help you, as a denizen of the modern-day,  get some of your zing back while adding a tang to your diet.

It’s also incredibly easy to make  – takes me 5 mins work and a few hours waiting – and can be made at a marked saving from buying commercially produced stuff.

Which is also good, because you can never be quite sure just what is in that tub of yoghurt you’ve just brought home from the supermarket, especially when food numbers get involved.

More on that later…..

Yoghurt is the child of bacteria. Certain desirable strains of lactobacillus are cultivated in a portion of milk to act on the lactose (or milk sugars) the by-product of which is lactic acid. The lactic acid then acts on the caseins or milk proteins and changes your milk into a thick custard-like liquid instead, which is – in turn – rich in many, many more of those bacteria than there were at the start of the process.

Yoghurt cream cheese

Yoghurt cream cheese

SAfety concerns

This last bit is really very important. Milk naturally contains many different types of bacteria – there are the ones that make yoghurt and there may also be the ones responsible for listeria, salmonella, tuberculosis, typhoid fever, diphtheria, brucellosis, and Q-fever as well as your good, old-fashioned e coli. Milk is a highly pathogenic liquid, keep it warm enough and all of those bacteria will grow – right alongside the beneficial bacteria that turn it into yoghurt.

In Australia, all commercial milk is pasteurised to render these bacteria harmless and thereby extend the life of the milk and protect the population from preventable diseases.

So, in ancient times, one could simply have left a bowl of milk somewhere warm and it would have become yoghurt all on its own without any real human intervention. Equally, it could have turned into yoghurt with a strong TB flavour and just a soupçon of salmonella. This can also happen today with raw milk.

All raw milk must be heated to kill the native bacteria. Boil it and then cool before adding your culture.

Strawberry Frozen Yoghurt

Strawberry Frozen Yoghurt

Why make your own?

Umm…because?

Yoghurt is one of those things that can save you a small fortune if you are a large user. A litre of milk costs $1 in many supermarkets at the moment and a kilogram of plain, natural or Greek  yoghurt can cost between $4 and $5.

Flavoured and diet yoghurts often contain more stabilisers and sweeteners than they do actual nourishment in the form of milk proteins.

Check out this video from our wonderful consumer advisers at the ABC’s The Checkout.

Apart from the sugar or artificial sweeteners, you are also looking at maize thickeners, and other thickeners made with soy-based lecithin, agar agar (406)  and caraganeen(407). Not to mention a whole host of other things I could not hope to cover adequately here.

Note the numbers on this supposedly natural yoghurt. 1442 is hydroxypropyl distarch phosphate. Apparently.

Note the numbers on this supposedly natural yoghurt.

These are often added to low or no fat yoghurts to remediate the texture of the product once the fats have been removed. The fat gives it the thick creamy texture that feels so good in your mouth, remove that and it becomes a somewhat thinner liquid with a greatly diminished taste.

However, if you make yoghurt with skim milk there are other ways to make it thicker without adding emulsifiers or stabilisers – and I will show them to you.

This is what the ingredients list on natural yoghurt should look like:

Greek yoghurt label

Greek yoghurt label

As you can see it contains milk, milk products and some latin words which name the cultures it contains.

You can use this yoghurt to make your own at home. You can then go on to make flavoured yoghurt for school lunches etc.

How to make your own yoghurt.

In order to make your own yoghurt, you need milk. This can be Cow’s milk, goat’s milk or even Soy Milk. You may wish to enrich your milk by adding cream or well-dissolved powdered milk.

You also need cultures. The four main commercial bacterial strains used in this country are: Lactobacillus acidophilis, L. bifidus, L. thermophilus and L. bulgaricus.

The last two are most often seen together in Greek yoghurts.

You can buy cultures online, or you can buy a tub of natural yoghurt at your supermarket and use a few spoonfuls of that. The fresher the culture the better your chances of achieving a good set.

You will need something to heat your milk in, something to measure the heat of the milk with and something to store your yoghurt in as it ferments.

Basically, you warm your milk, stir in the culture and leave it to sit overnight.

So, you will also need either a warm place or a way to maintain the heat of your yoghurt for at least 6-8 hours.

My mother used to mix her yoghurt in a bowl, wrap it in a towel and place it on the (internal) hot water heater overnight.

You could place your yoghurt in a thermos or vacuum flask, in a small foam cooler with a hot water bottle, you might even use a slow cooker turned to low, or place it in the oven with just the pilot light on. There is no need for fancy electronic yoghurt-making gadgets that make it all seem so very difficult.  Really, truly.

The yoghurt 'flask'

The yoghurt ‘flask’

I actually use a yoghurt maker that is nothing more than an insulated flask. It’s meant to be used with powdered yoghurt-making mixes, but works just as well with the technique I will describe in my next post (this one has been long enough!).

Add boiling water and then your yoghurt mixture.

Add boiling water and then your yoghurt mixture.

I’m planning on giving one of these away shortly, so stay tuned. There will also be quite a few posts to come which will show many different uses of your yoghurt that go beyond a breakfast item.

My latest batch of homemade yoghurt

My latest batch of homemade yoghurt