In my latest battle in the war against single-use plastics, I have banned shop-bought yogurt. As I rarely eat yogurt (I really only like it with curry or baked potato, ie with savoury foods) this is very unfair on poor L who consumes litres of it weekly. I’ve never really seen the point of the flavoured kind, which has cloying amounts of sugar and ‘fruity’ flavours which rarely resemble fruit in any way.
To compensate, I’ve become very serious in my yogurt making.
Milk – 750ml
Plain yogurt – 3-4 tbsp
There’s no end of advice to be found about what milk to use for your yogurt. In my experience, almost anything will do. I use semi-skimmed fresh milk (1.55% fat content) from the supermarket and the end result is thick and creamy and just fine. Different types alter the consistency and the flavour slightly. Whatever you opt for, the fresher the milk, the better the end result.
More important, I think, is the culture that you start off with. You can begin your yogurt-making career with powdered cultures bought in speciality shops, but this is, in my opinion, an unnecessary gimmick. What you really need is plain yogurt, and to get the culture ball rolling it pays to get a really good one. I started my process with a few tablespoonfuls of excellent cow- and sheep-milk yogurt from Pianporcino in the Val d’Orcia. Of course you can’t gauge from labelling just how many active helpful, milk-thickening, live active bacteria are swirling about in any given yogurt pot but you can bet that the food-industry giants skimp on those like they do on anything that is truly natural and beneficial.
As soon as you’ve made your first successful batch, remember to hold back a little of your yogurt to get the next one going.
Lastly, you need something to make your yogurt in. You can buy dedicated yogurt-making equipment but again – it’s not at all necessary. A glass jar, a towel and a shelf in a warm airing cupboard will do. I’ve opted for a vacuum flask – not the kind for drinks but the kind you can carry hot food about in. Mine holds 3/4 litre of liquid, hence the quantities given above. The important thing is that you create the conditions to keep the fermenting yogurt warm for six hours or more, to give the bacteria time to do their thing.
Heat the milk slowly, preferably in a fairly wide, heavy-bottomed saucepan, until bubbles start forming around the edge. At this point it’s pretty hot but not boiling, and you’ve killed some of the not-so-good bacteria that might fight off the thickening bacteria that you’re about to add (thermometre-obsessives will tell you this is about 82°C.) Then leave it to cool down, until you can rest your little finger in it without feeling scorched (about 45°C).
(My instructions now presume that you’re using a vacuum flask like me. You’ll need to adapt if you’re opting for some other method.)
Remove any skin that may have formed on the warm milk, then ladle out a small amount into the container and beat the starter yogurt into it. Add the rest of the milk and mix it all well. Close the lid, set the flask aside and don’t peek again for another six hours at least. Overnight or 12 hours is better. If conditions are right, the longer you leave it, the more of a bite the yogurt will have.
You should now have beautifully set, creamy yogurt which you can flavour with jam, honey, fresh or cooked fruit… anything really. You can keep your yogurt in the fridge for a week or more, though if you’re using a thermos you’ll need to pour it into another container before transferring it or it may not get cold enough to block the fermentation process properly.
For thicker Greek-style yogurt, line a sieve with a piece of cheesecloth or muslin, pour your fresh yogurt into it and leave it to strain: the longer you leave it, the thicker it will become. (The whey that drips out is rich in proteins and vitamins but low in fat – great for baking and very good, some say, for your skin and hair.)
Now that you have your own yogurt to use as a culture, you’ll need to save a few tablespoons to get your next batch going, so don’t be tempted to eat the lot. Tales of yogurt cultures handed down through generations abound. I’m told that you can freeze yogurt for emergencies (such as some uninformed person polishing off the whole jar while you’re not looking), and unfreeze it to get your culture going again. I have squireled a small pot away in the back of the freezer but have yet to test the theory.