My Science Project: Sourdough Starter

We are entering the 4th week of the ECQ #lockdown. ECQ stands for Enhanced Community Quarantine. It’s the time of the COVID-19 (Corona Virus Disease 2019) pandemic.

#stayhome is the catchword of the time.

One needs to either learn new skills or revive old dormant ones. The excuse “I have no time” no longer means much. Because, now, you have all the time in the world.

Ergo… my science project.

It’s not the first time I made a sourdough starter. I’ve had a couple of successful attempts at making a sourdough starter in previous years (decades).

However, on both occasions, I “cheated”. I primed my starter mixture with 1/4 tsp of instant yeast. That gave my starter a jump.

This time, it’s pure.

By pure I mean, all I used in the initial mixture was flour and water: 1 cup bread flour mixed in 1/2 cup tap water, in a glass jar. If there is life inside this mixture, or if it attracts life from the surrounding air, it will become evident in the first 24 hours: the mixture will froth up and bubbles will appear.

This is for Day 1.

It takes 5 days of repeated discarding and refeeding to create the (young) sourdough starter.

So by the end of Day 1, my sourdough starter appeared like this:


It looks promising. Bubbles are a clear sign of microorganism respiration. It is a good sign that the sourdough starter is alive.

The next steps, which will be repeated in the next 3 days, are:

1) Discard 1/2 cup of the starter mixture:


2) Mix the ‘refeed’ using 1 cup All-Purpose Flour mixed in 1/2 cup tap water:


3) Add the refeed and mix well with the remaining sourdough starter mix left in the glass jar.


4) Leave the jar slightly covered, and allow the starter to refeed and grow over the next 24 hours.

(To be continued…)

UPDATE: Day 2 (04.07.2020)

I realized the mayo jar I began with was too small. The bubbles had almost reached the brim, after only 12 hours. (I forgot to take a picture.) So I transferred the starter to a larger container — a cylindrical Lock n Lock.

At days end, here’s how it looked like…


Discarded 1/2 cup of the starter…


Mixed 1/2 cup tap water to 1 cup (~110 grams) All Purpose Flour for the refeed…


Added the refeed into the starter culture and mixed it well.

This is how the sourdough starter appears at the start of Day 3…


It’s alive. The bubbles tell me that. And they’re multiplying. And maturing.

(To be continued, Day 5…) ⌛🤔

UPDATE: May 6, 2020.

I have almost completely forgotten about updating my science project. No Day 5 update, however. Instead, it’s been about a month, and my sourdough starter has been keeping in the ref (fridge) for more than two weeks.

I have fed it twice already, since it began residing in the cold compartment. Last week I made Sourdough Ciabatta with 1 cup of the starter.


I fed the starter the usual 1 cup flour and 1/2 cup water, after baking, and returned it inside the refrigerator.

This is how it appears now…


It’s alive! 🤗👌