How to Make Greek Yoghurt
As far as yoghurts go, let’s be honest, who doesn’t like Greek yogurt! And not only is it a creamy and luxurious tasting item, if you are buying a brand which has live cultures – it is a source of probiotics. The process to make Greek yoghurt at home is very similar to that of ordinary yoghurt, but with some differences.
Note, if you want our full DIY guide to making regular yogurt, please read our Ultimate Guide to Making Yogurt at home.
Greek Yoghurt versus Ordinary Yoghurts
If you are a converted fan of Greek yoghurt (which I am going to guess at, seeing as you are reading about how to make it) then you might find it interesting to know that Greek yogurt’s thickness is not only – as commonly thought – due to a higher cream content, but rather is caused by the straining process that Greek yoghurt goes through.
Greek versus Ordinary Yoghurt: Nutrition
Besides being thick in consistency, Greek yoghurt also has some nutritional differences.
- Fat Content: Greek yoghurt does have a higher fat content than ordinary yoghurt, but this is mainly due to the fact the because some of the watery whey is removed when strained, thus making the yoghurt more concentrated, and the fat content is increased.
- Protein Content: Greek yoghurt contains roughly double the protein of regular yoghurt. A lovely thought to savor while you are eating your delicious Greek yoghurt – especially in this age of Paleo predominance. Jokes aside, the increased protein content is a great plus for vegetarians, and gives Greek yoghurt a high satiety level.
- Carbohydrate Content: Still remaining politically correct, Greek yogurt has about half of the amount of carbohydrates as regular yogurt.
Greek versus Ordinary Yogurt: Preparation
Seeing as the nutritional content of Greek yoghurt and regular yogurt has some striking differences – what are the differences then in the ingredients and preparation? Well, ingredient wise, traditional Greek yoghurt is made with goat’s milk. These days however most of the Greek yoghurt (it will probably say ‘Greek Style’ on the container) is made from plain old cow’s milk, just like regular yoghurt. The reason why Greek yoghurt is thicker and creamier than regular yoghurt is not so much due to what milk you use, but to the differences in preparation. Here are the three preparation steps which differentiate Greek yogurt from regular yoghurt:
- Culture: Greek yoghurt has its own specific set of bacteria, which you can get hold of either in the form of a purchased ‘starter’ or from a tub of live, cultured Greek yoghurt from the store. These bacteria are termed ‘thermophilic’, and they prefer a higher range of temperatures than their room temperature counterparts, the mesophilic bacteria which are usually found in cultures for making regular yoghurt at home.
- Straining: Greek yoghurt also goes through an additional process that makes it thicker, which is straining. During this time excess whey drains off, and the end result is a thicker consistency yoghurt.
- Extra cream: If you a looking for a super duper creamy version, you can also add some extra cream. This can be very nice if you are in the habit of using yoghurt in dips, soups, sauces and as a cream or ice cream substitute when serving deserts.
Now that we have solidified your wise decision to whip up some healthy, nutritious, tasty and versatile Greek yoghurt, let’s move on to choosing a culture.
Buying a Culture
Yoghurt cultures can be purchased in some stores, and online. If you are planning to purchase the culture, make sure that you do following:
- Go Greek. Buy a culture that is specifically for making Greek yoghurt. This culture will have the right strains of bacteria for reliable results. A Greek yoghurt culture will contain some or all of the following species of bacteria.
- Lactobacillus bulgaricus
- Streptococcus thermophilus.
- Lactobacillus acidophilus
- Lactobacillus casei
- Bifidobacterium bifidum
Try to get a starter which contains more than two strains of bacteria, as this will be a better probiotic, and make for a stronger and more resilient culture.
- Go Heirloom. When buying a yoghurt starter/culture make sure to avoid any which are termed ‘direct-set’ or ‘single-set’ cultures. This means that they are only meant to culture one batch of yoghurt, after which you must buy some more to culture the next batch. Look for starter cultures which are ‘heirloom’ varieties. These varieties will be able to not only turn your batch of milk into yoghurt, but culture strongly enough so that you will be able to use some of your finished yoghurt as starter for the next batch.
Using Live Yoghurt
If you do not want to buy a starter culture to make your Greek yoghurt with, you can also use some yoghurt from the store as starter. However, not just any old yoghurt will do – you must make use of a variety that it is:
Using a yoghurt as starter which is does not contain live strains of bacteria will be absolutely pointless. This is because it is those very strains of bacteria which you are looking for, and you definitely want them alive!
When choosing a store bought yoghurt to culture from, pick a brand which has a taste that you like. Most probably the combination and balance of the bacteria are producing that taste in the bought yoghurt which you like, and therefore you will get something similar when you make your own yoghurt from it.
You have probably guessed it already, but when I said ‘tasty’ I meant a tasty PLAIN yoghurt. Using flavored yoghurt as a starter – even if it is live – is not such a great idea. This is because there is a lower chance of the bacteria being alive and full of vitality in yoghurt which has been flavored, as the flavoring can damage them.
Should I choose to buy a starter culture – or just a pot of yoghurt?
Sometimes store bought cultured yoghurt does not have the vitality necessary to culture one’s home made yoghurt strongly enough for it to be able to keep on culturing your future batches. Because of this it can be better to just go for getting a good quality heirloom starter.
If you do however want to try using some live yoghurt to start with – then perhaps go for a variety sold at a farmer’s market. It might be that the bacteria are stronger and the yoghurt is fresher – and you might find that you can successfully make yoghurt for many batches from this.
If you find that the vitality and fermentation power of your yoghurt starts to drop after starting it with bought yoghurt as the starter – then I recommend that you invest in a starter. They will not break the bank, and if good quality, will give consistently good results.
Because Greek yoghurt cultures are thermophilic in nature, this means that they love warm temperatures. Between 108 and 110o Fahrenheit to be exact! If you do not happen to be living in such an incredibly stifling climate (which I sincerely hope not!) then you will have to decide on a way to keep your fermenting yoghurt at this temperature for 5-12 hours. There are quite a few options and ways to do this, check them out:
Possibly one of the easiest options, you can use your oven to keep your yoghurt nice and cozy for its fermentation period. The way to do this is to heat the oven up to 110o Fahrenheit (43o Celsius) and place the batch inside with a thermometer. Turn on the pilot light and leave. Check the thermometer every now and then to make sure that the temperature is being maintained.
Quick Hack – to keep your yoghurt from getting cooked
If you are part of a bustling family and there is a chance that someone else might want to use the oven, stick a post-it note on the oven door saying ‘Do Not Turn On’, to make sure that nobody cooks your yoghurt accidentally by turning the oven on to preheat!
Yoghurt makers are specifically designed for the purpose of making thermophilic ferments, so if you have one of these – of course, use it! If you don’t, but want to get one, you can pick up one in stores or online. Yoghurt makers are not essential, and you can definitely make yoghurt without investing in one, but they are super convenient, especially if you are looking at making a lot of yoghurt.
A cooler box filled with hot water can also do the trick, but the downside is that it can be hard to control the temperature. Using a thermometer, add hot water until the ambient temperature is just above 110o Fahrenheit (43o Celsius). Then close up, with the yoghurt inside.
Thermos Flask & Blanket
Many people have also had good results making their yoghurt in thermos flasks. As you will be warming up the milk anyway, once it is cooled to just above 110o Fahrenheit (43o Celsius) you can transfer it into the thermos flask! Make sure that the thermos flask which you are using is good quality and holds its heat well for optimum results. It is also a good idea to preheat the flask with boiling water, as otherwise it will not hold the temperature in the milk of 110o Fahrenheit (43o Celsius).
Electric blankets can make for good ‘yoghurt-warmers’. Simply wrap up the container of milk and culture when it has cooled to 110o Fahrenheit (43o Celsius) in the electric blanket and insert a thermometer. Then turn the blanket onto its very lowest setting and monitor. If it maintains the temp without raising it above 110o Fahrenheit (43o Celsius), then you have a yourself a great yoghurt warmer.
Quick Hack – Yoghurt Warmer Winner
If you have a yoghurt maker already, then that is probably your most convenient option. But if you do not, then my personal top favorite warming method is the thermos flask. a) Because it uses no electricity, and b) because it reminds me of my grandfather who was a Scotsman by descent – and did all of his cooking of rice in thermos flasks!
When it comes to the straining of your Greek yoghurt (very simple, I promise) there is something which you can try to get hold of which can make life easier. Most people usually use cheesecloth to strain with – normal kitchen sieves at not fine enough. This can be a bit messy however, so if you are thinking of making Greek yoghurt long term, have a look for a bouillon strainer for this particular job. Bouillon strainers have a very fine mesh, perfect to use for straining Greek yoghurt.
You can also purchase strainers which are specifically designed for yoghurt making. You can find these online, or in a store specializing in culinary ware.
Other options for straining Greek yoghurt include:
- Cheesecloth layered double lining a colander
- Dishtowel lining a colander
- Coffee filter lining a large funnel
While Greek yoghurt is traditionally made with goat milk, you can definitely use cow’s milk. In fact, if you are accustomed to the regular Greek, or Greek style yoghurt available from most common brands, a cow’s milk variation will probably be similar to the flavor which you are looking for.
Having said that, it is also perfectly ok to try out goat or sheep milk, if it is available and you want to experiment. The results will be a little different, goat will probably produce a thinner yoghurt, and sheep’s milk a thicker and sweeter version.
Besides the animal from which it comes, milk also differs in what treatments is has undergone. This can be split into 3 categories:
Pasteurized milk has been heat treated to 145°-212°Fahrenheit (63°-100° Celsius) for varying lengths of time and then packaged. These milk types usually culture very well, as they are not denatured, but also do not contain naturally occurring bacteria which might compete with the yoghurt culture’s bacteria.
- Ultra Heat Treated (UHT)
Ultra heat treated milk is heated to above 275° Fahrenheit (135° Celsius) for a short space of time. The high temperature causes the cells of the milk to become denatured, which renders them unsuitable for culturing.
- Raw Milk
Raw milk is milk that has not been through any processing. It contains its own specific makeup of micro-organisms. These can sometimes compete with the bacteria from your yoghurt culture, causing problems with the fermenting process. Raw milk also usually produces a thinner yoghurt than that made from pasteurized milk. If you are interested in using raw milk for making your yoghurt, you will have to add in a couple of steps to the yoghurt making in order to ensure that no foreign bacteria invade your culture. I will outline briefly how to do this below:
How to Make and Maintain the Starter Yoghurt When Using Raw Milk
– Heat 1 cup of milk to at least 160o Fahrenheit.
– Leave to cool to either room temperature to 110o Fahrenheit (43o Celsius).
– Mix in the starter and allow to culture for 5-8 hours, at 110o Fahrenheit (43o Celsius).
The resulting yoghurt is your starter. Use two tablespoons of this in under a week’s time to make another batch. Before that you can use two tablespoons to make your yoghurt. Keep maintaining the starter culture batch of yoghurt side by side with your yoghurt for eating.
Overall, the most reliable option, for consistent results is a pasteurized full cream milk, which preferably has been pasteurized at not too high a temperature. However if you want to enjoy the benefits or raw milk and do not mind processing yourself at home, by all means use it. Do not however try to use UHT milk, as this will result in a failed yoghurt fermented.
Making Greek Yoghurt
Now that we have looked at ways to culture the milk, how to keep it warm, how to strain it and what milk to use, let’s put it all together. In 12 hours or less you could be enjoying some thick, sumptuous Greek style yoghurt!
Note: You can adjust the quantity of milk up or down, the recipe amount is merely a convenient quantity to work with. However, you must keep your ratio of starter culture to milk at 1:1.25 teaspoons of culture to cups of milk.
What You Will Need:
- 1 pints (1 liter) Milk of your choice
2-3 tablespoons starter culture (purchased starter which is activated or readymade live cultured yogurt)
- Container to put the milk into to culture
- Pot big enough to hold milk
- Strainer of choice
Step 1: Warming the Milk
Once you have gotten all items together, pour the milk into your pot and heat to 160° Fahrenheit (71° Celsius), measuring with the thermometer. Turn off the heat and allow to cool to 110o Fahrenheit (43o Celsius).
Step 2: Adding the starter
Once cooled, add in 2-3 tablespoons of activated starter or readymade live yoghurt, mixing thoroughly.
Step 3: Culture at 110o Fahrenheit
Now pour the milk into your container(s). Place them in your selected warm place, and culture them at 110o Fahrenheit for 5 – 12 hours. If the milk becomes semi ‘solid’ then this means that it is ready. If you tilt the container and it comes away from the side in a jelly like formed shape – you are done!
Step 4: Straining
Decant your yoghurt into your strainer of choice, and leave to strain suspended over a bowl to catch the whey for a couple of hours. The whey will drip into the bowl, leaving a thicker yoghurt behind.
Step 5: Whisk, Store, Enjoy
To get a really smooth consistency, you can give the finished yoghurt a quick whisk before putting into containers and refrigerating. The whey you can set aside to use as a healthy addition to soups, stews and baking.
There you have it! Thick Greek style yoghurt at less than you would pay for in the store, and much fresher. Important: Do not forget to save some aside to keep as starter for your next batch of yoghurt! Unless you are using raw milk for your yoghurt making, in which case do not forget to maintain the starter yoghurt side by side with your eating yoghurt.
If you heading up a busy schedule, or have a lot of make-it-yourself stuff to do in the kitchen it might seem impractical to add in yet another thing which one has to do. But in the case of yoghurt, making it at home is very quick.
If you have a farmer’s market close at hand, then you might already be treated to the availability of probiotic rich yogurt, and better even Greek, but in some areas this is not the case. Many store bought brands of yoghurt contain additives and preservatives, and lack all probiotic benefits. In which case making one’s own yoghurt is a no brainer.
Besides being healthy, yoghurt is also one of the most flexible ingredients in the kitchen. You can eat it on its own or with fruit or cereal, or it can be incorporated into soups, breads, dips, dressings and deserts. This is especially true of Greek yoghurt, as the thicker texture lends itself well to these uses.