I have made yoghurt before, putting a bowl of milk/yoghurt mixture wrapped in towels in the airing cupboard and have to say that the results were very variable. I decided to try again after reading this post about making yoghurt in a Thermos flask.
I've been doing this for a few weeks now and the yoghurt is great. I was also pleased to find a new use for the oldest kitchen utensil I own, this wonderful old Thermos flask.
My mother gave me this flask a few years ago, I always remember it being at home when I was small and I think it was passed to us from one of my grandmothers. I have no idea how old it is but would guess at over 60 years. The stopper is cork (no plastic used in flasks back then) and I cover it in foil so I can wipe it clean. It maintains the heat really well, far better than my modern flask.
Basic yoghurt making instructions,
- I basically follow the instructions from the link above. The first step is to heat the milk to destroy the bacteria present in the milk. This step is important if using fresh milk and particularly so if like me you try to save money by using milk that is reduced in price at the end of its shelf life. (I have made yoghurt from longlife UHT milk and then this step can be left out as the milk will not contain any bacteria - just heat up to the temperature needed to add the yoghurt starter.)
- The milk is then left to cool, I don't use a thermometer but test it by touch, if I can keep my finger in it for a few seconds but it is almost uncomfortably hot seems to indicate the right temperature!
- I then mix in some commercial yoghurt. I usually use about a third of a small pot of Yeo Valley natural yoghurt - about 50 ml to a litre of milk. Make sure that the yogurt used is live yogurt.
- The milk mixture is then poured into the flask which I have first scalded with boiling water and then left for around six hours.
- We like thick yoghurt, so the next step is to strain it. I use a clean ironed tea towel (which would be virtually sterile) in a colander. It is worth watching this stage quite closely or it can over drain and become very thick, I find thirty minutes is about right.
- We mostly eat our yoghurt with fruit and so at this stage I transfer it to a pot (bit messy this stage) and add honey to taste. After mixing in the honey, the yoghurt is ready to go in the fridge to cool.
A litre of milk makes just under half a litre of thick yoghurt. The savings are not high if full price milk is used but it is slightly cheaper, the real savings only come if I can find a bargain at the supermarket but it tastes brilliant so its worth making anyway.
I have also made soft cheese by accident when I forgot I had left some yoghurt draining. After a couple of hours it was very thick so I mixed some chopped chives and black pepper into it and it tasted fine. I will do that again and experiment with adding different ingredients.