Good, pot-set yoghurt is awesome stuff. It’s full of beneficial bacteria, it can be used in alllll sorts of ways, it lasts for ages, and it’s dead simple to make.
We won’t bang on too much, but just before sharing the recipe, here’s a list of some ways we use homemade yoghurt:
- Eating it as it is, with a dollop of jam, or lemon curd, or maybe some dehydrated fruit. What a delicious dessert!
- Serving with granola or muesli instead of milk
- Adding to smoothies, milkshakes and breakfast açai bowls
- Blend with mango to make delicious mango lassi
- Blending with fruit & freezing into yoghurt-pops for healthy(-ish) summer treats
- Using as the leavening agent in cakes or muffins. Our favourites are Quick Jam Cake and Lemon Yoghurt Cake
- Adding crushed garlic, grated cucumber to make tzatziki. Add some lemon juice, ground cumin, coriander and maybe a bit of mint and you’ve got raita to serve with Indian curries
- Use as a base to make your own Indian tikka sauce/marinade
- Make grilled flatbreads by mixing with flour and frying
- Mix with mustard, mayonnaise and chopped spring onions (or wild onion grass!) to make a lighter yet creamy potato salad dressing.
- Add to fried onions, garlic, thyme and wild mushrooms to create a creamy sauce for steak or grilled portobello mushrooms
- Use instead of sour cream if you don’t have any for nachos, sauces, dips
- Use to ferment whole chillies in
- Strain it for a couple of days in the fridge to make labneh (a great cream cheese alternative)
- Use as a hair and/or face mask!
With so many brilliant applications, it pays to make your own!
Making yoghurt looks a little different in each household, so before going over the nuances and potentially getting tangled up in confusion, we reckon it’s helpful to know that the absolute basic essence of making yoghurt goes like this:
- Heat milk to *almost* boiling
- Allow to cool to ~45
- Add a dollop of pot-set yoghurt
- Keep it warm for ~8 hours
And that’s it!
The nuances go a little bit like this:
1. Heat milk to *almost* boiling
Before starting anything, make sure that all equipment you’re going to use in the process is sterilised first.
You can measure the temp of your milk exactly if you like – you want it to reach 85C. This is hot enough to kill off harmful bacteria, and break down (denature) proteins which helps create a thicker yoghurt.
If you don’t have a thermometer, the signs of “almost boiling” milk are steam and a bit of frothiness.
2. Allow to cool to ~45C
To make yoghurt you need to introduce specific microorganisms (Streptococcus thermophilus and Lactobacillus bulgaricus) who will feed on the sugars in the milk and produce lactic acid, which give yoghurt its characteristic tart flavour. These bacteria (sometimes called “cultures”) have a prime reproduction rate between 40-46C, so that’s what we aim to cool our milk to.
It takes a while for almost boiling milk to cool down – often around half an hour if you’re doing 2L worth – so consider speeding up the process by whacking the saucepan full of milk into a container/sink of cold water. Be aware that the temperature will drop slowly at first, but more rapidly the lower it gets, so once your milk hits around 47C, keep a fairly close eye on it.
If you don’t have a thermometer, dip an ultra-clean finger in: if the temperature is hotter than your body temp, but cool enough for you to keep your finger in for 30 seconds, it should be about right.
3. Add a dollop of pot-set yoghurt/starter culture
Pot set yoghurt is full of Streptococcus thermophilus and Lactobacillus bulgaricu, so adding a good dessert-spoon sized dollop to your denatured/warmed milk is effectively introducing all the good bacteria needed to create a new batch of yoghurt. You can also purchase yoghurt starter culture if you’d rather start with a pure strain of each bacterium.
You can start each batch of yoghurt with a spoonful of the previous batch, but do be aware that every time you open your jar of yoghurt, you’re increasing the chance of introducing air-born yeasts and bacteria and whilst yoghurt has enough lactic acid in it to stop many of them taking over, over time smaller colonies of these will build up, especially if you’re feeding them with fresh milk every time you make a new batch of yoghurt. For this reason, it generally advised to start fresh with either a dollop of commercially produced pot-set yoghurt (which has been produced in sterile conditions) or packaged starter culture.
Some people say add the dollop to the pot and stir well before filling your jars, other people say place it at the bottom of the jar and carefully pour milk on top so it’s not disturbed. The first method is said to disperse the cultures and aid in overall rapid fermentation; the second method is done in the belief that the dollop forms a stronger colony to begin fermenting, and both methods are said by different people to result in thicker yoghurt. Essentially, it’s different strokes for different folks, so try them both out and see what happens, and then just do whichever one you feel you like the most.
4. Keep warm for ~8 hours
This is all about providing a suitable temperature for the starter cultures to thrive, and ideally the mixture should be kept between 40-46C for between 4-12 hours. You can do this in many different ways once you’ve sealed your yoghurt jar as listed below. The main thing is to leave the jar undisturbed during this time: any movement will disrupt the growth of your beneficial bacteria.
- Put jar in a thermally insulated container with hot water in it. ‘Yoghurt makers’ are basically mini eskies/coolers designed to fit a jar with space for some hot water around it. In winter, we like to wrap a thick towel around the container and keep it in a warm spot in the house. You can use an actual esky/cooler (those old Dècor wine coolers are pretty nifty) if you’re making a couple of jars worth. All these types of containers can be found at op-shops for cheap: we’ve never seen a yoghurt maker thermos for more than $3.
- Use a blanket box, thermal cooker or hay box (watch historian Ruth Goodman explain hay box cooking at the 27-minute mark of this episode of Wartime Farm). Essentially, the concept involves quickly putting your yoghurt jar in a well-insulated box, drawer or basket and keeping it warm that way. You can add a hot water bottle as well during winter to keep it nice and snug.
- Put jar in a microwave (turned off) along with a source of stable heat – a hot water bottle or jug filled with boiling water next to the jar is great.
- Keep jar in a dehydrating machine set to 40-45C. This is our least preferred method as it calls for an active use of energy rather than the passive energy conservation of the other methods, but it’s good to know it exists.
How do I know it’s ‘done’?
As mentioned, it will take anywhere from 4-12 hours for yoghurt to ferment fully. We find that we’ll make yoghurt in the evening before going to bed and by the morning it’s ready. You can tell your yoghurt is ready when it pulls away from the side of the jar in a solid lump. When you lift a spoonful of yoghurt, it should fall away in sheets or layers. You may see some watery yellowish liquid (called whey) surrounding the yoghurt, which is totally fine. If your yoghurt doesn’t pull away from the jar sides, put it back in an insulated spot with a heat source again for a bit longer.
Once you’re happy with your yoghurt, store it sealed in the fridge for a week or more.
* Full cream milk will yield thicker yoghurt than light milk. You can add a bit of powdered milk to your milk before heating to create a thicker result if you like. We like to look out for discounted good quality full cream milk and use that.
* Watery whey will pool at the top of your yoghurt over time: this is perfectly normal. you can choose to pour it off (if you want thicker yoghurt) or stir it back in (if you prefer smoother more runny yoghurt).
* If you find that your yoghurt is stringy or slimy rather than like thick pot-set yoghurt, chances are that wild yeasts or other bacteria have gotten in to the mixture somehow. This isn’t harmful at all, but you may not love the texture: if that’s the case, use this yoghurt up for cooking or making smoothies/frozen yoghurt dishes and start fresh on a new batch. Do not use the stringy batch as the started, as the bacteria present will just cause the next batch to come out the same.
* If you want super thick and creamy yoghurt, you can strain some whey from it overnight through a scalded clean handkerchief or piece of muslin.
* You can experiment with dairy-free yoghurts, but you’ll need to investigate which cultures work for different non-animal milks. Many of these sorts of cultures are available in health food stores these days.
Take a look at some of our recipes for using your homemade yoghurt…