I don’t use this recipe anymore! I have a new and improved recipe that uses pectin instead of gelatin for the thickener. See here for the new recipe. I left this recipe here for anybody that prefers using gelatin for thickener rather than pectin, though I recommend the pectin recipe.

About five years ago I decided to learn how to make yogurt. So I googled it – what else? 🙂 I found a lot of recipes and explanations, but they all seemed to make it more difficult than it should be. So I tried many different variations and finally settled on what I’ll describe in this post. First I’ll give the recipe, and then, for those who are interested, I’ll describe my different yogurt making experiments and provide some more yogurt information.

My recipe is very simple. It takes only about 10 minutes to make the yogurt (not including the 8 hours fermentation time). Here it is:

Update

Update on 11/8/2017: For two quarts of yogurt (8 cups), I reduced the amount of starter yogurt from 1 cup to 1/2 cup. I’ve decided this makes the yogurt more tangy after 8 hours of fermentation, which I like.

Update on 5/16/2016. I now ferment for 8 hours. Also, add the vanilla to the cold milk, and heat the gelatin for 15 sec.

Update on 10/20/2013. I changed the fermentation time again (from 3 hours to 6 hours).

Update on 10/10/2012. I changed the fermentation time and the amount of gelatin.

Ingredients

Gather the following:

1. Two Salton yogurt makers
2. Two one quart empty yogurt containers. I use containers from Mountain High yogurt
3. One half-gallon pitcher
4. A half-gallon of 2% milk, minus one cup
5. 4 teaspoons sugar (if you prefer to sweeten the yogurt a little bit; this amount is 1/2 teaspoon per cup)
6. 3 tablespoons of gelatin
7. 1/4 teaspoon of vanilla
8. 1/2 cup of starter yogurt

Here’s a picture of the Salton yogurt makers, containers, and pitcher:

Procedure

Fill up the pitcher with 2% milk, less 1/2 cup (to make room for adding the yogurt with the live culture later). Mix in the vanilla (it mixes into the milk better when the milk is cold). Heat it in the microwave until it gets to 110°F. I used a candy thermometer the first time to find out it took 6:00 minutes in my microwave. Now I just heat it for 6:00 minutes so I don’t have to use the candy thermometer any more. Here’s a picture of the heated milk in the pitcher. Notice the black mark on the pitcher. I use the same pitcher and always fill it up to the black mark so that I don’t have to measure anything:

Add the sugar to the heated milk and mix it up.

Put the gelatin in a small bowl, add some cold water, and mix it up. Then heat it in the microwave for 15 seconds. It looks like this:

Add some of the heated milk and mix it. This step probably isn’t necessary, but I do it to make it easier to mix the gelatin into the pitcher. It looks like this with the milk mixed in:

Mix the gelatin mixture into the heated milk that’s in the pitcher.

Now we need to add the yogurt ‘starter’ to the mix. The starter yogurt has the live bacteria that will cause fermentation to occur. I use 1/2 cup of previously made yogurt. If you don’t have previously made yogurt, then you can use yogurt from the store that has live bacteria. I think most do (the label should say it has live bacteria). An example is Mountain High yogurt. I mix it in a separate container first to make it easier to mix into the pitcher. It helps get rid of the yogurt ‘clumps’. Put a cup of previously made yogurt into a container and add some of the heated milk and mix until there are no yogurt ‘clumps’. Add a little more milk and mix it some more. This step just helps mix the old yogurt into the milk:

Add the yogurt/milk mixture into the pitcher with heated milk and mix it up.

Pour the mixture into the two yogurt containers:

Put the containers into the yogurt makers:

Let the mixture ferment in the container for 8 hours. Afterwards, put in the refrigerator overnight. I’ve read that its not good to stir the yogurt or jostle it too much after it’s fermented, but before it has set up.

That’s it! Enjoy your delicious homemade yogurt!

Now I’ll provide some additional information to anybody who is interested.

What is yogurt?

You can google and find lot’s of information about this. I’ll provide a nutshell.

The concept of yogurt making is very simple:

1. Heat up milk to 110°F
2. Add some yogurt that has a live culture (i.e. live bacteria)
3. Keep it at 110°F for a while to let it ferment.

During fermentation, the bacteria eats the lactose and produces lactic acid. The lactic acid combines with proteins in the milk to make the yogurt thick and give it the tangy flavor. People who are mildly lactose intolerant can tolerate yogurt because a large amount of the lactose is removed by the bacteria. There are a lot of claims for the health benefits of yogurt, and I think some controversy. I think it is good for you, but you can decide for yourself.

Given that simple recipe, there are the following choices:

1. Do you need a yogurt maker?
2. How can you make the yogurt thicker?
3. How much yogurt should be added to the milk?
4. How long should the yogurt ferment?
5. What else can you add to the yogurt while it ferments?
6. What bacteria should be used in the yogurt?

I’ll discuss these choices below.

Here are some links for more info:

http://en.wikipedia.org/wiki/Yoghurt

http://en.wikipedia.org/wiki/Probiotic

Cost and Calories

I don’t make the yogurt to save money or cut calories, but it’s interesting information. The cost and calories is about the same as for the milk used to make the yogurt. I added 7 calories for the 1/2 tsp of sugar.

Homemade yogurt cost: 56¢ per quart
Homemade yogurt calories per cup: 127 calories, 45 from fat

Here’s the cost and calories for plain Mountain High yogurt. It’s not really a fair comparison on the calories because the plain yogurt isn’t fat-free.

Mountain High yogurt cost: $2.50 per quart
Mountain High yogurt calories per cup: 230, 60 from fat

That doesn’t include the cost of the yogurt maker. I’ve probably made about 250 quarts in 5 years, so that would come to about 13¢ per quart.

Do you need a Yogurt Maker?

I don’t think you need one, but I haven’t tried it without. You need a way to maintain the constant temperature of 110°F for about eight hours. I found various ways, with and without electrical power, that people use to do this. The Salton yogurt makers just make it very easy so you don’t have to worry about it. They were inexpensive – around $16 each. They are very simple. You just plug them in, and they maintain a constant temperature of 110°F in an insulated chamber. I decided to try one. Worst case, I would be out $16. However, it worked so well I wound up buying another one so that I could make two quarts at a time.

Some other ways I saw that people use are: put the heated yogurt mixture in an insulated container and put it in a warm place; use a crock pot; use the oven; etc.

As a side note, the Salton yogurt makers come with a container for the yogurt. I don’t use them; I use the old containers from store-bought yogurt instead. They are more convenient for me. Here’s the container that comes with the Salton maker:

Yogurt Thickness

I use gelatin to thicken the yogurt because my ‘customers’ like it that way. Homemade yogurt without a thickener (gelatin for example) isn’t as thick as we find in most stores in the U.S. I’ve traveled to Poland for business, and they serve yogurt that has the same consistency as I get with homemade yogurt and no thickener. If you look at the ingredients of yogurt products found on your store shelves, you’ll find they use some kind of thickener, such as gelatin or pectin.

I tried different things to make the yogurt thicker naturally, i.e. without adding a thickener. For example: use of whole milk; mix in powdered milk; ferment longer. None of them resulted in yogurt like we’re used to.

I noticed some store yogurt uses pectin. Pectin needs sugar and I don’t put much sugar in my yogurt. There’s a type of pectin that acts on calcium called ‘Pomona’s Universal Pectin’. However, I couldn’t get it to dissolve in the milk. I tried heating it like I do the gelatin, and it didn’t work.

The gelatin works well. It’s not exactly the consistency I’m looking for, but it’s close enough until I find something better.

Amount of Starter Yogurt

The different recipes I’ve seen use differing amounts of starter yogurt. I tried 1/2 cup per quart and 1/4 cup per quart. I’ve settled on 1/4 cup per quart (for this recipe, which makes two quarts, I use 1/2 cup). It didn’t seem to make a difference in the thickness, but it seems to produce tangier yogurt after fermenting for 8 hours.

Fermentation Time

I’ve tried different fermentation times from 2 hours to 8 hours, but I’ve settled on 8 hours. The fermentation time effects the thickness and flavor.  The longer you ferment, the more sour (aka ‘tangy’?) the flavor. Also, the yogurt gets thicker with longer fermentation times. I use the gelatin, which means the time doesn’t matter for thickness. However, without the gelatin, I’ve found that it’s quite a bit thicker after 8 hours compared to 3.

Adding Flavors Before Fermentation

I add a small amount of vanilla before fermenting. The only other flavor I’ve tried adding is honey, and I didn’t care for the result. I added 6 tbsp for 1 quart. Maybe that was too much.

I don’t have much motivation to add ingredients before fermenting, because we can just add whatever we want afterward. We use yogurt on cereal, add it to fruit, make yogurt drinks, use it in recipes, etc.

Bacteria in Yogurt

From what I can tell after doing a little research, two bacteria are required:

– Lactobacillus bulgaricus
– Streptococcus thermophilus

There are three others in the Mountain High starter yogurt that are added, I think, for their probiotic benefits:

– Lactobacillus acidophilus
– Lactobacillus bifidus
– Lactobacillus casei

You can go online to find out some properties and probiotic benefits (if any) of these bacteria, for example:

http://en.wikipedia.org/wiki/Probiotic

Should the Milk be Pre-Heated to 200°F?

Most of the recipes that I’ve seen call for pre-heating the milk to 200°F (some recommend less, such as 185°F) and holding it there for 20 minutes or so, and then letting it cool to 110°F. The high temperature kills any competing bacteria that may be in the milk. I’ve never done this, and haven’t had any problems. My theory is that the milk I’m using has already been pasteurized and homogenized, and I don’t need to heat it up again. Eliminating this step also saves the time and hassle of waiting for it to cool, and determining that it’s cooled to the correct temperature.