What was the origin of the word scratch when used in this sentence (details inside) ?

To cook from scratch means to prepare food from the most basic ingredients. An example is cake. Most people use a mix from a box from the store. That’s not from scratch. To do it that way, you have to start with cake flour and add all the other ingredients to make the finished product.

Now I will go search for the origin.

It’s from sports from the 18th century when a line would be scratched in the earth to be a starting line. Cool! GQ

https://www.grammarphobia.com/blog/2011/01/scratch.html

According to this it probably started with the sport of cricket.
I’d think that the “starting point” changes over time. For me, it’s not using ready-made ingredients. For my Mother it was starting with the basic ingredients such as flour on up. For my Grams, she started by growing her own grain & grinding her own flour & milking the cow & then she completed the meal from there. I have NO clue what my Greatgrams considered her starting point. With many of those younger that me, it means not starting with carryout. I guess the term would be “homemade”.