# Sourdough Starter Starter Guide

Today I want to write about something that I’ve never written about — baking! In particular, sourdough bread. Sourdough bread is made without commercial yeast found in a packet. While it does require a bit more work, the end product (a nice loaf o’ bread) really makes the process worth it. I started really caring about sourdough bread on January 6, 2019, when Steven, my sourdough starter, was born. Here’s a picture of Steven.

A sourdough starter is essentially just a mixture of flour and water, but it’s been inoculated with the yeast and bacteria that naturally live in the air around us.

I followed this recipe for my sourdough starter, which actually uses pineapple juice as the liquid for the first three days. This helps jumpstart the activity in the starter.

https://savorthebest.com/wild-yeast-sourdough-starter/

But how does this work? The bacteria in the starter break down the carbohydrates in the flour into simple sugars, and these sugars feed the wild yeast. The bacteria that live in the starter are called Lactobacilli, and produce lactic acid throughout this process. This is called lactic acid fermentation. Meanwhile, the yeast that live in the starter are undergoing alcoholic fermentation, converting carbohydrates from the flour into ethanol. This acidic and alcoholic environment makes the starter inhospitable to other bacteria that you don’t want in your starter.

This process isn’t immediate, though. The first few weeks that I did this, there were still some unwanted bacteria in my starter. I could tell because it had a really awful smell. But after keeping with this for awhile, the bad bacteria eventually died, leaving a stable culture of good bacteria and yeast.

To maintain a sourdough starter, you do something called “feeding” it. This consists of removing some of the starter and giving it fresh water and fresh flour as food. At first this seems wasteful, but there are a lot of things you can do with the discarded starter! If you look up “sourdough discard recipes” you’ll find a bunch of ideas. For example, brownies, banana bread, … the list goes on. I made these brownies with sourdough starter today!

When I feed my sourdough starter, I keep $\frac{1}{2}$ cup of my sourdough starter, and mix that with 113 g fresh flour and 113 g of fresh water. So, even though you discard some starter every time you feed it, you’re always building on the work that you’ve done before. I’ve seen different ratios that can be used to feed a sourdough starter, so I don’t really know how important the exact ratio is. You’ll notice that after feeding your sourdough starter, the yeast really start to produce a lot of $CO_2$ and the starter gains a lot in volume. So fun!

To maintain a sourdough starter you have several options. If you leave it on the counter, you need to feed it once or twice a day. This is a good option if you bake regularly. If you leave it in the fridge, you only need to feed it once a week, and you should let it come to room temperature before adding more flour and water to it. If you leave it in the freezer, you can kind of forget about it until you want to bake again. You can follow these instructions for how to get it ready for baking again.

https://www.thespruceeats.com/freeze-sourdough-starter-428055