Tuesday, March 30, 2010
Fermentation is an exciting, magical process in which naturally occurring microorganisms are allowed to colonize and alter food - for the better. It is the way many of our ancestors preserved food, in some cases making it more digestible, and (perhaps most important of all) created the delicious heady flavours fermented foods are known for. Fermentation is the process that turns grape juice into wine, cabbage into sauerkraut or kim chi, and milk into yoghurt and cheese. Black tea, coffee and even chocolate are all fermented foods!
Fermentation at home is a dying skill, though. Modern society's fear of germs and obsession with hygiene means that it is seen as risky and somewhat radical. In reality, the over-use of antibacterial wipes and soaps is only contributing to the growth of antibiotic-resistant strains of bacteria, and the hyper-cleanliness of our modern world has arguably contributed to the alarming rise in childhood allergies in the last decade. We are losing touch with the vibrant fermentation traditions of our native cultures, as well as missing out on food that is truly alive, literally fizzing with vitamins, enzymes and beneficial bacteria.
Fermentation is not hard! You don't need a mask, gown, or even a thermometer for most basic projects. People have not been fermenting food for thousands of years because it is difficult, or fraught with danger. I have been making my own yoghurt for ages now, successfully keeping alive the same culture for months at a time. I enjoy the gentle rhythm fermentation winds through my days. The flavour and texture is superb, and it is full of natural probiotics. In addition, fermentation of milk can apparently make it tolerable for those with lactose intolerance. Best of all - I can now make a litre of yoghurt for around $1, rather than buying it for $5!
You will need:
A 1 L glass jar
1 Tb of ready-made yoghurt ("Try Me" brand, from Bharat Traders amongst other places, has given me best results. Jalna was a flop.)
Around 800 mL milk (up to 1 L if not using powdered milk)
1/2 cup powdered milk (optional)
Place milk into a saucepan and whisk in powdered milk, if using. (I used to never do this, but have become less purist, as it does give a thicker, creamier yoghurt. All commercial yoghurts add it, as "milk solids".)
Heat the milk to just before boiling. Stir milk while heating to avoid sticking to the bottom. (Alternately, forget like I usually do and just clean out the pan later.)
Set the milk in a sink full of cold water until it reaches the point where you can hold a (clean) finger in it for 10 seconds without beads of sweat popping on your forehead. In other words, it should be pleasantly hot - above body-temperature, like a lovely warm-to-hot bath. If you forget about it and come back to stone-cold milk (as I inevitably do) - just reheat until you reach the pleasantly hot point described above.
Pour a little boiling water into the jar to preheat it. It doesn't need to be sterilised (just clean).
Whisk starter yoghurt into the milk. Resist the temptation to add extra - yes, 1 Tb really is enough! Too much and the culture gets "crowded" and doesn't set properly. In the olden days, the yoghurt remaining on the sides of the empty ceramic crock would be enough to culture the new batch. Pour milk/yoghurt mixture into the jar through a sieve.
Cap the jar, wrap in a towel and place in an esky or similar. My esky isn't even insulated and it still works. Leave overnight. Longer is fine if you forget (yep, that's me again - fermentation is so forgiving!) The longer you leave it, the sourer it gets. It will firm up more when you put it in the fridge.
How easy (and delicious) is that!? You can also make this with organic milk, or even with skim milk plus skim powdered milk for low-fat yoghurt.
We are really passionate about fermentation, for its health benefits, its connection to human history, as well as its guerrilla nature, that we're somehow flipping the bird to so much of what we don't like about modern Western society - its plastic-fantastic, hyper-clean, standardized homogeneity. It's a great way to take control of more of your own food, bypassing mass production. If you're interested, I urge you to read Sandor Ellix Katz's incredible tome, Wild Fermentation. As time goes by, I hope to share more interesting projects with you, such as sourdough bread, sauerkraut and home-made ginger beer. Happy fermenting!