by J.B. Cheski
A resume of
webpage instruction at
cheski.net

It will cost less than twenty percent of the store price. It won't have travelled hundreds of miles, in fact no further than your nearest source of milk.

It can be as firm as you like and you can play around with a variation of tastes, almost on a par with cheesemaking.

A double boiler is ideal for heating the milk, as raising the temperature over boiling water prevents the milk from sticking to the pan. I use a stainless steel stockpot with a mixing bowl on top.

Preferably a gas cooker, both for heating the milk and growing the culture (yoghurt). For different methods you will have to look elsewhere, as I have little experience with those.

An easy-pour container holding 2L. I use a ceramic (Corning glassware) coffee pot, which is easy to clean. A slotted spoon, a knife and long-handled teaspoon, all of them stainless steel.

Now we come to the most important item: the THERMOMETER. Make it a digital one as these are easier to use and more accurate.

Then the ingredients: MILK and a STARTER. You can please yourself as regards the fat content of the milk. I use semi-skimmed (half-fat).

The starter is a little bit of yoghurt (with the emphasis on "little"), either store-bought or your own. I prefer to use the former and mix and match different types of culture.

When you buy yoghurt to use as a starter, be sure that it says "live" or "bio" on the container. Some yoghurts are stone dead by the time they reach you and will not grow on in your milk. Obviously we are talking about plain, unflavoured, unsweetened yoghurt here.

That is all. No thickening agents. No gelatine (Heaven forbid! That would undo all the nutritional advantages of making your own.) No extra milk powder or dried milk. Absolutely nothing. Except some tender loving care.

Heating the milk:

Pour the cold milk into the top bowl and replace the lid. I have washed the already clean bowl again with hot soapy water, right before using it and kept it filled with clean boiling water for a few minutes to sterilize.

Raise the temperature over a medium to low gas flame and after a few minutes insert the probe of the thermometer. Watch it until the temperature reads 80 degrees Centigrade (180 degrees Fahrenheit).

Take out the probe and switch off the gas. Let it sit for two minutes, stirring once halfway through to prevent a skin forming.

Even with the gas off, the temperature will creep up a few more degrees; probably up to 82 degrees C.

Now we come to the place where the yoghurt will grow: almost a mini-oven inside an oven. The heat is provided by the pilot light only. The pan inside the oven has been warming there for a few hours. In my case it is a deep stewing pan with a teflon lining, 25cm diameter. I have measured the temperature inside the pan and it usually reads 41 degrees C.(Approx. 108F) With the internal heat of the warm milk it probably goes a little higher.

Try to keep the oven and pan from cooling down by keeping the oven door closed and acting very quickly when you put the pan in and out

You will need four sterilized glass jars of 1/2 Liter capacity each. Make sure they fit side by side into the oven pan. Put them inside the oven pan to get warm before you start heating the milk.

Whilst you are waiting for the milk to heat, put one rounded teaspoon of commercial yoghurt into each jar and then quickly put them back in the oven to stay warm. No lid needed.
The mixture of cultures I prefer is L.(=Lactobacillus) bulgaricus, L. acidophilus, L. Bifidobacteria, S.(=Streptococcus) thermophilis.
You may be able to obtain these in tablet or powder form at your local healthfood shop.

Fill a clean bucket halfway with very cold water. Place the full jug into this. The milk will have already lost 10 degrees C by pouring it into the jug. It will take about five minutes for it to cool down to the required temperature. Take off the foam that has formed from the agitation of pouring. The slotted spoon does this nicely. It remains in the jug for stirring the milk, to ensure that the temperature stays even throughout the jug.

Now you really have to get your skates on, for you cannot afford to let the temperature of the milk drop below 49 degrees C.

As soon as the Thermometer reads 49 degrees C, I rapidly take the jug out of the cooling water and to the stove.

Gently take the pan with the glass jars out of the oven, (closing the oven door immediately). Divide the milk evenly over the four jars and stir the starter through.

Put the jars in the pan gently back into the oven. This part of the sequence must be done swiftly to prevent the temperature of the milk falling too low.

Come back after 8 1/2 hours and take out the pan carefully, without jostling. It will look identical to when it went in. A gentle tap on the surface will reassure you that it is in fact beautifully set.

Very very gently remove the yoghurt one jar at a time from the pan to the fridge. This is where you can do most damage to the consistence of the yoghurt.

It needs 8 hours minimum in the fridge. This will set it further and make it even more delicious to eat.

Set yoghurt can be thickened even further and turned into Greekstyle yoghurt by straining it through a cloth.

The chilled yoghurt is a mixture of casein (milk protein), lactic acid (converted from lactose or milksugar), fat and water. The yoghurt looks and feels firm, because of the precipitated casein solids. These can no longer remain dissolved once fermentation turns the milk acid.

To make the yoghurt taste milder, we can drive off the lactic acid with the water by letting it drip out through a piece of cheese cloth. This can be purchased in cookware shops. It is usually bleached. Cut off a length that will fit inside a sieve or collander or steamer insert, with a generous overlap to accommodate the yoghurt. The cloth will need washing and sterilizing in boiling water prior to using.

The jar with the yoghurt can be placed upside down on the cloth and left in place, or the yoghurt can be scooped out straight onto the cloth. Cover the pan with a lid, put in a cool place and forget about it for three or four hours.

By that time most of the liquid will have dripped out and you are left with a substance like whipped cream. This is particularly effective when using full cream milk. In fact, true Greek yoghurt is made with cream added to the milk, to make it extra rich. What remains is a custardlike substance which tastes almost sweet.

Cleanliness is of the essence in yoghurt making. The incubation time is 8 to 9 hours, and pathogens are just as happy to incubate as the good bacteria.

The double boiler method prevents the milk from sticking to the top pan and the residue is really minimal. I wash the pan while the milk in the jug is cooling down. Air drying is deemed better than the use of a tea towel.

Some people advocate rinsing the top bowl with cold water before pouring in the cold milk, as a means to prevent sticking even further. My own experience has been the opposite .
The jars can be properly sterilized by putting them into a largish pan with a steamer insert.
Usually nine minutes in steam is considered to furnish adequate protection against bacteria. I must admit, I do sometimes skip the steaming session and merely fill the washed jars with boiling water for a few minutes.
So far I have been getting away with this. When the yoghurt is meant for vulnerable people, small children or the elderly, or somebody with an impaired immune system, one obviously wants to take the utmost care.

Copyright, 2001, 2002.
J.B. Cheski
One print allowed
for private use only.