Swaddled in a snow-white towel, my little bowl of homemade yogurt is tucked up with my hot water bottle, calmly doing its thing. Soft, quivering, its surface as still as a village millpond, this is yogurt as it was meant to be, without sugar, fruit or flavouring. A pot of gentle, unsullied purity. It takes all my willpower not to peep until the warm milk and yogurt have been working together for a good five hours. It is while the milk is still warm that most of the curdling activity takes place, so keeping it at the optimum temperature for as long as possible is a bonus. This is where a yogurt maker would come in handy, but I am not a gadget person. It seems to work fine with my hot water bottle.
I find myself mildly irritated by the current television advertisem*nt for a French yogurt which insinuates that sourness is a bad thing. Sweetness creeps through our commercial food like a slow-moving virus, and I for one am glad of yogurt with a snap of acidity to it. That is surely the point: dairy produce with a shudder of freshness to it.
I am not convinced that making your own yogurt is much of a money saver, although homemade yogurt can work out cheaper if you use a few tablespoons from one batch to make another. There is plenty of wonderful commercial yogurt about, with and without fruit, and I have my favourites that I feel lost without; but there is also fun to be had in stirring warm milk with a little milk powder and some live yogurt and making your own batch.
Why the milk powder, you ask? Well, I like the thickness that milk powder brings to the party, producing a rich, wobbly result. It is unnecessary though, and you need not add it at all if you are after yogurt for drinking or adding to your cooking. But sometimes a luxury version is called for, thick enough to stay in a heap on your spoon.
I have started my day with this ancient form of dairy produce for over 30 years, and I sometimes end with it, too. I can often be found tucking into a tub of goat's yogurt before I go up the wooden hill. Could it just be this live, soured-milk product that has allowed me to live life without a doctor for all these years? Who knows.
You need to keep your utensils spotless for making any sort of dairy produce, just as you might with ice cream. Rinsing the bowl and whisk in water from the kettle isn't a bad idea. The warm bowl will help your friendly bacteria get going. You simply warm the milk, whisk in the milk powder (if you are using it) and the yogurt, and leave it, wrapped up, in a warm place such as the airing cupboard, next to the Aga or near a radiator. A long period of warmth at the beginning is the clue to success. Once it has cooled, no amount of warmth will give it life.
If you want sure-fire success then a Thermos flask will come in handy. You lose the quiet and tender moment of gently shaking the bowl to see if your yogurt has worked, but the constant warmth does near guarantee a firm set. But you will inevitably lose some of your hard work no matter how thoroughly you scrape it out of the flask.
I was recently reading Geetie's Cookbook (£18.99, Grub Street), Geetie Singh's story of the pain and joy involved in setting up Britain's first truly organic gastropub. I was impressed by the fact that she makes her own yogurt – just as her mother has for years – using a tea cosy.
Whether it's a hot water bottle or a tea cosy, yogurt obviously likes being at home.
A SIMPLE HOMEMADE YOGURT
There are as many ways to make yogurt as there are to spell it. This is the one I use when I want a result that is not too thick – say, for breakfast muesli or a smoothie.
2 heaped tbsp organic yogurt
500ml organic milk
3 tbsp milk powder
Bring the yogurt to room temperature – this will stop it cooling the milk too quickly. Warm the milk to no higher a temperature than 46C. This is the optimum heat, but a few degrees more or less will probably still work. If you don't have a thermometer, then test it with your finger. If it feels comfortably warm and rather good then it is probably about right. Whisk in the milk powder then pour on to the yogurt. Immediately cover the dish in clingfilm, wrap it up in a thick towel (or put it under a tea cosy, or next to a hot water bottle) and put it in a warm place overnight. The next day, transfer to the fridge and let it chill thoroughly.
EXTRA CREAMY YOGURT
This is a richer yogurt than the simple homemade version – thick and creamy and mild tasting.
400ml organic milk
100ml single cream
2 tbsp milk powder
3 tbsp yogurt at room temperature
Bring the milk and cream up to 46C – or as near to that as you can, then whisk in the milk powder till it has dissolved. Pour into the yogurt and stir, then tip into a spotlessly clean, warm bowl. Wrap in clingfilm, then put in a warm place (such as the airing cupboard) with a hot water bottle close to it and a towel placed over the top. Leave overnight. Transfer to the fridge, covered, where it should keep in good condition for a few days.
BAKED SALMON WITH CHILLIES AND YOGURT
The yogurt is a balm here, cooling the chillies. Serves 4.
4 large salmon fillet pieces
200g natural yogurt, not strained
For the spice paste:
3 tbsp olive oil
40g piece of ginger
2 medium-sized, hot chillies
1 heaped tsp garam masala
1 heaped tsp ground turmeric
zest and juice of a lime
To serve: coriander leaves and grated lime zest, olive oil
Rinse and pat dry the salmon fillets then lay them in a shallow pan. Make the spice paste: peel the ginger and finely grate it into a bowl. Slice the chillies in half lengthways, scrape out their seeds, then chop finely. Add to the ginger, with the spices. Grate the lime zest and reserve it, and add the juice to the spice mix. Season with salt and a little black pepper. Stir in the yogurt. Spoon the yogurt mixture over the salmon and turn each piece over so it is well coated. Leave for 15 minutes or longer (but no more than an hour).
On foil, grill under a moderate heat for 10-15 minutes until the fish is pale gold on top. When a flake of fish comes away cleanly and the fish is opaque, it is ready. Chop the coriander, toss it with the lime zest and a little olive oil. Serve the salmon with some of the lime and coriander on top.
Email Nigel at nigel.slater@observer.co.uk or visit theguardian.com/profile/nigelslater for all his recipes in one place
