With this recipe a water-kefir sourdough bread can be made entirely with water-kefir and there is no need to add bakers yeast at all. First, for those who don't know what water-kefir is, I shall explain that it is a brew obtained when kefir grains are cultured in a sugary aqueous solution. If you are running only the traditional kefir in dairy milk, I suggest that you feed about 2 teaspoons of your grains in ~ 500 ml water sweetened with a tea spoon of barley malt extract, or any sweetener like honey or maple syrup will do. I confess that even though I haven't this myself, I see no reason why it shouldn't work. After one or two days your water-kefir brew should be bubbling away nicely and you are now ready for your bread making; note that the bubbling is from the bottom where the grains prefer to be while feeding in aqueous solutions. Second, for those who have never had a go at making sourdough I must warn you that even though you might find the procedure a bit daunting to follow, don't worry, once you tried it hopefully you will soon have the hang of it. After all it will only take you one and a half days to have your sourdough bread, which is very quick indeed.
So long your that water-kefir has a good quick to it you will reliably create a good sourdough starter. Here it is what you will need to make your own just overnight.
Mix the flour with your lively water-kefir so that you get a lump free thin batter, this may be done directly in the jar. You may use less liquid if you like. Cover and leave overnight in a very warm place. I put mine in the airing cupboard. Then feed your water-kefir grains with another teaspoon of whatever sweetener that you are using, and top up with water.
For those unfamiliar with sourdough bread making this is an intermediate stage necessary to increase gradually the bulk of your fermented flour in order to enable you to make a decent batch of bread. So the following morning you are going to add to your starter, which should be bubbling away nicely, quite a good lump of flour.
In a medium bowl mix your starter with the above ingredients. Mix the whole thing vigorously with a wooden spoon, add enough water-kefir to make a nice working dough. Knead it until elastic, cover with a damp cloth or plastic, and leave for a few hours in a very warm place. Mine goes back to the airing cupboard. In the afternoon, if everything goes well, it should look a lot bulkier and spongier, and if so you are now ready for the last stage. Otherwise wait until the next day or, if you are in a hurry, add a bit of bakers yeast in the next stage.
At this stage an experienced baker can easily adapt any recipes to this water-kefir sourdough. What really matters is to keep track of the amount of stron white flour used. This is very important if you want to get the salt right. I aim at using a total of 1,350 g white flour and keep track of the amount used in the previous steps by writing on the flour packet the weight before start. Then I add one part in three - 500 g - of whole wheat flour, and one part in ten - 150 g - of either brown spelt or rye flour, for extra flavour. Whatever flours you decide to use, add the water-kefir slowly and stop when the dough gets dry enough to knead. For the beginners sake I give here a recipe with just two flours, which should give a lightish easy to make bread.
Oven at 220º C, 425º F, gas mark 7.
Tip the sponge in a large pre-warmed bowl and add it to the flours, salt, and oil. Slowly add enough water-kefir to obtain a good kneading dough. Knead vigorously until the dough is soft and elastic. Cover with plastic or damp cloth, and leave to rise in a warm place until doubled. Knock down, divide in three equal portions, put them in well oiled tins. Cover again, this time with oiled cling film so that when you remove it doesn't stick to the dough and deflate it. Again, let the bread prove in a warm place. When well risen, remove the cling film and bake in a very hot oven for about 35 to 40 minutes or until it sounds hollow. Cool on racks.
In this recipe I've used very little of rye or brown spelt flours. You may with great success increase amount of the latter. However the same doesn't apply with the former. A dough with a higher proportion of rye flour can become very sticky and the above recipe is no longer applicable. For scrumptious water-kefir sourdough apple or pear breads see here.