Taking care of your Sourdough Starter
Once your starter is up and running it is really quite simple to keep it going. The traditional way is to remove half the volume of starter and replace it with an equal weight of flour and water mixed 50/50, so that the total volume of starter remains the same. If you can't bear to tip away starter every day, you can double up the amount by not throwing any away and adding an equal weight of flour/water mixture. Of course if you do this the volume will increase exponentially and soon outgrow any container that you might have - so you'll need to bake regularly or start gifting starter to your friends. If you are pressed for time you can just pop the starter on a kitchen scale and add equal weights of flour and water then mix it in, this works perfectly well.
The time may come when you cannot feed your starter every day, if you go away on holiday for instance. If you are only away for a coule of days, just give the starter a good feed with a less hydrated mix than usual, one that has more flour than water, then pop it into the fridge. The yeast and bacterial will reproduce more slowly in a thicker starter and the lower temperature will also slow things down. If you are away for longer than a couple of days you should put the starter into the freezer and put the micro-organisms into hibernation. I have successfully kept starters in the freezer for six months and they have reactivated within two days of bringing to room temperature and feeding. Another way of preserving a starter is by dehydrating it. Yeast and bacteria are hardy organisms and can survive for long periods of time as spores, remaining dormant until conditions are suitable for them to resume their life cycle. The best time to dehydrate a starter is when it is most active as it will have a maximum population of yeast and bacteria. You can dehydrate the starter with a commercial dehydrator or by using a fan oven. In either case you should use a low setting, 40 to 45 C, and keep an eye on progress.