Delicious and easy home-made yoghurt

About two years ago it was time in my make-your-own, towards-sustainability, slow-food, know-where-your-food-comes-from, enjoy-your-food path to have a go at making yoghurt.  So I did what most net savvy people would do, I started an online search for the best yoghurt making recipe and was left completely confused.  Bring to a gentle boil, whatever you do don’t let it boil, heat to 90 °C for 10 min, heat to 85 °C for 30 min…. Let milk cool to 40 °C, 45 °C, 43 °C, 48 °C….  Then it hit me, if there is this much variation between recipes it probably doesn’t matter.  And anyway, they didn’t have thermometers 3000 years ago.

It took me about 6 months of all edible, but varying degrees of scrumminess, yoghurt to get to where I could consistently make yoghurt the way I like it (thick, creamy and tasty) with minimal fuss and effort.  Here is my recipe

Equipment:

• Kettle for boiling water
• Heavy bottomed saucepan
• Spoon
• (Measuring) cup
• Wide mouthed thermos
• Timer (only required for those of us who forget to come back and check the milk while it’s heating)

Ingredients:

• Milk
• Skim milk powder (optional: use if you like thicker yoghurt)
• Boiling water
• Yoghurt culture (see Notes below for more info)

1.          Measure your milk into the saucepan (I normally make 1 L).

2.          Add 1 heaped teaspoon of milk powder per 500 mL of milk (i.e. I add 2 heaped teaspoons t 1 L of milk) and stir to mix.

3.          Place saucepan on low heat.

4.          Check milk often, I use a timer to ensure I check it every five minutes.  Give it a stir if you like.  It’s less likely to stick to the bottom of the saucepan if you do stir it.

5.          When milk starts to froth it’s time to turn off the heat. Don’t worry if you miss the frothing stage and it’s simmering/boiling, it doesn’t make any discernible difference to the finished product.  But if it does get to boiling stage you run the risk of it frothing and bubbling over the top of the saucepan and then you have to clean up boiled and dried up milk – Yuck!

6.          At this stage, boil water in your kettle and fill your thermos.  Screw the lid on your thermos and leave until you milk is ready.

7.          Let milk cool for about 2 to 3 hours.  Less time in winter and longer in summer.  Exact temperature doesn’t matter.  If you want a gauge, wash you hands well and stick your pinkie finger in – it will feel just nicely warm when ready.

8.          When milk is ready, pour the water out of your thermos, using the stream of water to sterilize your spoon.

9.          Place your yoghurt culture (about a heaped tablespoon for up to 1 L of milk) in your thermos using your sterile spoon.

10.       Pour some milk into your thermos and stir well with sterilised spoon.  Pour remaining milk in and stir again with sterilised spoon.

11.       Screw lid onto thermos and leave for 18 to 24 hours in a position where it won’t get moved around.

12.       Open thermos, transfer yoghurt to storage container and place in fridge.

13.       Enjoy when chilled.

Notes:

• Milk – I have only used full-cream but skim should work too – just increase the skim-milk powder to ensure a thick-set yoghurt.  I started using “normal” milk and now use organic.  Both work well.  I have used both homogenised and unhomogenised with success.  Unhomogenised often gets a yellow skin on the milk as it cools.  I assume this is the butter fat settling out.  I just chopped this up with my sterilized spoon and add it into the thermos.  The yoghurt making process seems to process the skin and it has disappeared once the yoghurt is ready
• Yoghurt starter culture – This is personal taste but my favourite is a mix of Jalna Yoghurt (Acidophilus, Bifidus and Casei) and Farmers Union Greek Yoghurt (S. thermophilus and L. bulgaricus).  The Yalna gives it the lovely taste and  Greek Yoghurt gives it the creamy, thick texture. I use 1 level tablespoon of each (or 1 ice-cube of each) per 1 L of yoghurt.  Then in subsequent  batches just a heaped tablespoon of my last batch of yoghurt.
• Mixed yoghurt starters – I find that over time the quality of my yoghurt for using as a starter culture drops off.  In particular, I seem to lose the Greek yoghurt bacteria that give it the thick, creamy consistency. I have found that my long culture time  means my yoghurt maintains it’s quality for more batches but eventually it still becomes runnier.  So I add an ice-cube of Greek yoghurt and keep going.  Eventually I start all over again with fresh culture.  My culture normally lasts a few months and I make yoghurt once to twice a week.
• Freezing yoghurt starter cultures – I freeze yoghurt in ice-cube trays to use as future starter cultures.  Then I just pop them in a labeled zip-lock bag, squeeze out the air before sealing and store in the freezer until required.  I am yet to have a batch lose it’s potency – I’ve probably stored them for up to a year.  I haven’t yet tried to store my own yoghurt this way to use as a starter culture
• Contaminated yoghurt starters – occasionally I find some non-desirable bacteria get into my yoghurt (blue-cheese tasting mostly).  I normally can’t taste this (or can barely taste it) while eating the yoghurt but it seems to magnify in the next batch of yoghurt.  It’s time to ditch the yoghurt and start with fresh cultures.
• Yoghurt culturing time – Yes, my yoghurt culturing time is longer than most people’s recipes.  I think I may often end up with cooler milk than many recipes and so it takes a bit longer.  I find that the longer culturing time makes my mixed starter culture last for many more batches of yoghurt. Also, I like a really thick, tasty yoghurt.  Plus it’s just a convenient length of time for me: I heat my milk while making dinner, put the milk in the thermos just before going to bed, it hasn’t really cultured long enough when I leave for work the next morning but it is absolutely delicious by the time I get home.  Pop it in the fridge and it’s nice and chilled for putting on my muesli the next morning.