Since we are dealing with live fermentation, using the highest quality ingredients available to you is very important.

Flours
The flours that you use to feed your starter as well as bread making should always be unbleached, organic and/or stone ground.

Water
The water used for feeding and baking should always be filtered. If you use tap water, it will mess with the fermentation.

Temperature
Temperature is also another important ingredient when it comes to sourdough.

When feeding your sourdough and mixing the dough, all of your ingredients should be the same temperature.

Use a thermometer, check the temperature of your flours.

If you are using bottled or filtered refrigerated water (like me), allow the water to come up to room temperature so it's the same as the flours.

Jars:
A glass jar with a lid is always the best option for a sourdough starter.

The glass will not interfere with fermentation and you will be able to see the fermentation bubbles and how much it has grown.

A wide mouth glass jar is best as it makes the mixing easier.

In the beginning, when you are creating a sourdough starter from scratch you want to use a larger vessel like the 24-ounce, wide mouth mason jar.

After 10-12 days, you can reduce the starter amount and move it to a 16-ounce, wide mouth mason jar for daily feedings.

Once you've decided to even further reduce your starter to reduce flour and waste, I like using an 8-ounce glass jar.

The smallest jar pictured is an old coconut yogurt container that I repurposed!

You can use any glass jar you have, as long as it has a lid that can be screwed on tight.

Kitchen Scale:
In order to feed your sourdough starter the right amounts of flour and water, you will need a kitchen scale.

Test to see if your kitchen scale is accurate. It's best to have one that can go as low as .1 grams. Accuracy is very important when it comes to sourdough.

Rubber Spatula:
To mix the sourdough starter, use a rubber spatula. I like using a smaller rubber spatula that can get into corners of my vessel.

A chopstick is a also a great tool to mix mature starter, flour and water.

Your main sourdough starter is what creates the levain.

When you are ready to make bread, you will feed your sourdough starter and use some of the discard to create a second sourdough starter aka the levain.

Take a small amount of your mature sourdough starter (main sourdough starter at its peak) then mix it with fresh flour and water to create the levain.

The levain is then used to naturally levain your bread loaf!

If you were to use your sourdough starter for the bread dough, you would not have any more sourdough starter left for next time.

Any young sourdough starter, 1 week to 1 month old, should be fed daily, some say even twice a day (every 12 hours).

Young sourdough starters will result in a flatter and sometimes more dense loaf.

Most bakeries have a starter that is 13+ years old!

All sourdough starters will have stages of rising and falling.

After a starter has been fed, it will grow (rise) and show bubbly activity. Once it has reached its peak, it will start to fall. Once it has fallen, it is time for a feeding.

As a sourdough starter creates wild yeast with the bacteria that naturally occurs in the air and the flours, it will have a slight tangy smell. Hence the name 'sour'dough.

After the sourdough has matured, feeding it bi-weekly and moving it to the refrigerator is an option for those who don't plan to make bread every week.

If you make bread once or more a week, a daily feeding is recommended for a strong and healthy starter.

When feeding your starter every day, you will always be left with discard and unfortunately it will most likely end up in your trash as we are not able to repurpose it most of the time.

To reduce waste, I recommend reducing your starter to a very small amount and storing it in your refrigerator.

Since fermentation slows during colder temperatures, you will only have to feed your starter every 3-5 days.

I only feed my starter when I want to make bread the next day.

If you are feeding daily, a 1:10:10 feeding ratio with very small amount (1 gram mature starter, 10 grams flour, 10 grams water) is great to keep waste low.

If you are feeding bi-weekly, you have to store the starter in the refrigerator to slow fermentation drastically. Before I feeding, remove the starter from the refrigerator and allow it to come up to room temperature until it is bubbly and double in size. This takes about 4-6 hours.

When the starter is bubbly, it is time for a feeding and creating the levain.

First, remove all of the starter from your jar and move it to a bowl.

The below mentioned measurements are examples using the 1:5:5 ratio. 1 part mature starter, 5 parts flour and 5 parts water.

Depending on how much starter or levain you need, you can increase or decrease the amounts but use the same ratio. However, if you want to speed up fermentation, decrease the ratio (ex.: 1:3:3) and if you want to slow down fermentation, increase the ratio (ex.: 1:10:10).

The below measurements I am providing are what I use to feed my starter and create my levain. This levain is enough to make 1 large bread loaf and is ready for use after about 12 hours.

To feed your Main Sourdough Starter, mix together:
3 grams mature starter
7.5 grams bread or all-purpose flour
7.5 grams whole wheat or rye flour
15 grams filtered water

Once mixed, allow the starter to sit at room temperature for 2-3 hours before moving it to the refrigerator.

Use the discard to make your levain!

As mentioned, a sourdough starter will have stages of rising and falling.

After feeding your sourdough starter, it will trap natural gases and ferment. This means it will grow and show active signs of fermentation - bubbles.

Once the sourdough starter has reached its speak height, it was start to fall in volume. That when it’s ready for a feeding.

Same with the levain, once it’s reached its max height, that’s when you should be using it to make bread.

The below mentioned measurements are examples of what I use to create my levain for 1 sourdough bread loaf.

Keep in mind that both the ratio of the feeding and the temperature of your house determines when the levain will be ready for use.

Here I am using the 1:5:5 ratio and keep it in a 73°F-75°F, draft-free environment. This levain will be ready for bread making after 12 hours. This is why I usually create my levain at 8/9pm so that is grows overnight and I make the bread dough the next morning.

Bread Starter Feeding (Levain):
10 grams mature starter (discard)
25 grams bread or all-purpose flour
25 grams whole wheat or rye flour
50 grams filtered water

If you want to make bread just a few hours after creating the levain, use the below measurements.

20 grams mature starter (discard)
20 grams bread or all-purpose flour
20 grams whole wheat or rye flour
40 grams filtered water

Mix the ingredients well, loosely fit the lid then move it to your oven with the light on and the oven OFF. This will create a warm (about 80°F) and draft-free environment which encourages your levain to grow very fast.

The levain is ready to be mixed into the flour dough once it’s reached its max height.

To test if the levain is ready, do the float test. Get a small bowl of water and gently add 1 teaspoon of the levain. If the levain floats it is ready to be used. If it drops to the bottom of the bowl, it’s is not ready yet.

If the levain has had its rise and is now falling and you see streak on the sides of your glass jar, it needs to be fed and it cannot be used for bread making.

This takes practice. Always set an alarm and check on your starter and levain frequently.

The most common way to see how much your sourdough starter has grown is to feed it, flatten the top with your spatula then using a rubber band to mark the height of your sourdough starter.

If you are feeding your starter and creating a levain (second starter that is used to make the bread) and want to make bread ASAP, there are two things than can help you speed up that process.

Change the feeding ratio. A 1:2:2 ratio (25 grams mature starter, 50 grams flours, 50 grams water) will grow much faster than a 1:10:10 ratio (10 grams mature starter, 100 grams flours, 100 grams water). The more mature starter you use, the faster it will grow and ready for use. Alternatively, if you’ve fed your main starter but are not ready to create a levain for bread dough just yet, using a 1:10:10 ratio for the levain will be a good option as it gives you more time before making the bread dough.

Temperature is also important. It can slow down or sped up the starter and levain process. Colder temperatures will slow fermentation and warmer temperature will speed it up.

If you do not have a warm and draft free spot in your house for the sourdough starter and levain, I recommend storing it in your microwave or the oven with the light on. The oven heat should be off!

Using a thermometer, check the temperature of these areas. 73°F-82°F is ideal.

Once in a while you may find that your sourdough starter is acting up and not growing as fast as it used to and not showing as much activity.

This can happen due to temperature changes (seasonal temperature changes), changes in the flours for feedings, not feeding the starter regularly, incorrect feedings, etc.

To re-set your starter, do a 1:1:1 feeding every 12 hours for 2 days. Discard all but 10 grams and feed it 10 grams flour and 10 grams filtered water.

Allow it to grow at room temperature and monitor it closely.

Once it's back to it's normal activity, resume with a 1:5:5, 1:6:6 or 1:10:10 feeding.

Although you should feed your sourdough starter at least once every 24 hours, it is very hard to kill your starter.

If you neglect your sourdough starter for too long, it is possible that it is dead and you will need to start over.

Signs that your starter is dead:
A visible layer of dark “hooch”. Hooch is a liquid layer that forms on top of your starter. It is the alcohol given off as wild yeast ferments. When your starter is neglected for an extended period, the hooch tends to turn from clear to dark-colored.

Visible signs of mold, or an orange or pink tint/streak.

In those cases, throw out your starter and start over.

Take your starter with you! Kidding, although a lot of bakers do take their starter with them wherever they go!

If you are unable to feed your starter at least once every 5 days, you can move it to the freezer.

You want to freeze your sourdough starter when it’s in its active stage.

Feed your sourdough starter then let it rise at room temperature for a 4-6 hours until it’s bubbly and active.

You can now move the starter to the freezer (making sure it’s in a freezer safe container and the lid is air-tight) for up to 1 month!

To bring a frozen sourdough starter back to life, move it to the refrigerator first for 10-12 hours, then feed the starter and allow it to grow at room temperature.

You can then use part of your starter to create your levain for bread baking.

The Ultimate Sourdough Starter Guide by Joshua Weissman
https://youtu.be/sTAiDki7AQA

Ways To Put Your Sourdough Starter On Hold by Alex French Guy Cooking
https://youtu.be/P_hR43eMgug