Here is my step-by-step guide for how to clean a starter jar or container. No matter what container you store your sourdough starter in you are going to want to remove all the dirt and bacteria from it so your sourdough can prosper! If you know how often you should clean your sourdough starter container and you are ready to do it for the first time (or first time properly!), follow this guide:
The first thing you need to do is find another bowl, cup or jar to store your starter in. Having 2 identical containers makes things easier, but you can store your starter in pretty much any clean, food-safe container. A cup covered in plastic wrap will be fine.
Feed the starter in your clean container using your normal refreshment ratio. If downsizing to a small jar temporarily you can use the same ratio as usual with smaller amounts.
Dry unwanted starter is hard to clean with a cloth. Try to make things easier for yourself by removing as much starter from the jar as you can. Use a spoon to scrape the unwanted starter. You can also give it a rinse under the tap to remove any loose bits in the container.
Use your standard washing-up detergent and warm water with a cloth to remove the dirt. I’ll often leave the jar to soak in the water for 30-60 minutes before returning to it to remove the stubborn bits of dried-on dough.
Rinse the container under the tap. Next, half fill the container with water and add a teaspoon of baking soda. Give it a stir and gently rub the sides of the container with clean fingers to remove any more dirt. If you have a lid to your container you can give the jar a shake like you would shake a “jam-jar salad dressing”. Give the container a rinse under the tap to remove any residue left.
Drying the container with a tea towel has the potential to transfer bacteria or fibres which might hamper the healthy bacteria that you want to cultivate. For this reason, it is best to air dry the container