How to make your own Sourdough Starter
There are a lot of different guides online on how to make your own sourdough starter. Some guides even claim you can have your starter ready in a week or less. I am not going recommend that anyone uses a starter that is less than 14 days old. It takes time for the good bacteria to take over and for your starter to get properly established. It can take more than 14 days for your starter to actually be ready to bake with so keep that in mind. The water, flour and the temperature and humidity in your home all play a part in how long this takes.
What you will need:
A mason jar with a solid metal lid. a spoon for stirring. White flour and water. I live in Toronto and use tap water without issues, however if you live in an area with highly chlorinated water you should use filtered/bottled water. Scale for measuring.
Day 1: You are going to mix 20 ML of water and 20 grams of flour and place it in a mason jar. Use the flat metal lid and leave it on top without screwing it in place. You should never seal it tightly, the bacteria in your starter will begin releasing gas which needs to escape the mason jar, or else it will break/explode. Leave in room temp.
Day 2: 24 hours have passed and it is time to begin the discard and feeding process. You will take 20 grams of your mixture and discard the rest, (throw it in the trash not down the sink) mix the 20 grams of unestablished started with 20 ML of water and 20 grams flour. This is considered a 1.1.1 feeding ratio. Equal parts starter, water and flour.
Day 3-5: Repeat the process from day 2. Take 20 grams unestablished starter and mix it with 20 grams flour and water. between days 3-5 you may notice your starter is doubling or more in size. This is called the "false rise" your starter is doubling but it is not ready to bake with. Continue feeding and discarding every day.
Day 6-10: Continue the same steps as before of discarding and feeding. Your starter may no longer be rising. This is when a lot of people give up and think they killed their starter. Don't worry, this is normal and it is a sign that you are on the right track.
Day 11-14: Continue discarding and feeding your starter. You may notice that your starter is beginning to rise again. if by day 14 your starter has doubled in size 3 days in a row it may now be ready to bake with! If it is not yet doubling or more, don't worry just continue discarding and feeding your starter every day. It takes patience and time.
Once your starter appears to be established you can take more starter and feed it with more flour and water so that it will be compatible with the recipe you are going to use. Most bread recipes I see use between 50-150 Grams of starter. So in order to have enough starter you will increase your ratio. What I often do is plan to have 200 Grams of active starter. That leaves me with 100 grams that I can use, and another 100 grams that I will put away to feed for another baking day. To do this I take 20 grams of starter, 100 ML water and 100 Grams of flour. this is considered a 1.5.5 ratio feeding.
Peak: Your starter is at peak when it is no longer rising up. Signs of peaking are a flat top with bubbles, the starter appears to be sinking down with drag marks on the sides of the jar.
Feeding Ratio: Feeding ratio refers to the amount of starter you use vs. the amount of flour and water you use to feed it with. For example a feeding ratio of 1.1.1 is equal ratio feeding. An example of that would be 10 grams starter, 10 grams flour and 10 grams water. A feeding ratio of 1.2.2 would be 10 grams starter, 20 grams flour, 20 grams water. Once you believe your starter has become established and ready to bake with, I personally recommend a different feeding ratio than 1.1.1. If you want a strong starter you are going to want to feed it even more. I am a big believer in something called stiff starter which is when you use 65% or less hydration. Work your way towards a higher feeding. For example take 10 grams of starter and mix it with 20 grams of flour and 20-15 grams of water. The next day take 10 grams of starter and mix it with 30 grams of flour and 20-30 grams of water. Gradually work your way towards a 1.5.5 or 1.10.10 feeding ratio. Or a 1.5.3 or 1.10.6 feeding ratio if you want a stiff starter.
Temperature: The ideal temperature for a sourdough starter is room temp between 20-23 C. If you keep your starter in room temp you will need to feed it at least every 24 hours. Once your starter is established enough to bake with you can let it sit in the fridge on the days you are not baking with it.
Humidity: The humidity level in your home will have an impact on your starter and your baking. Adjust your ratios if necessary. An important reason why you should use a solid lid instead of a coffee filter or a other type of cloth as cover, is because they harbor moisture which puts your starter at risk of growing mold. If its very humid this will put your starter even more at risk.
Discard: Discard is the amount of starter that you have left over after a feeding. If your starter is not established you have to throw it away in the trash. Once your sourdough starter is established you can begin to use discard for discard recipes, such as sourdough crackers, or roux in soups or sauces.