I'm a specialty coffee roaster and I also brew all of our cold brew, at a previous job I made the recipe for our 400+ gallon batches on converted beer brewing equipment. Here's my actual recipe I'm currently using:

I'm somewhat of a coffee enthusiast, and honestly that's all there is to cold brew. I prefer hot brew over ice because more smell, but other than that it's good!

If you want to improve the taste of your coffee, buying whole bean coffee and grinding it yourself will take you 80% of the way to the platonic ideal of coffee, so if you don't do either or both things already, that's a good place to start.

I respect the fact that people are connoisseurs of coffee or wine or whatever—you do you, I'm not about to argue for the case that there's an overabundance of joy in the world—but tbh your method sounds like a decent method as it is.

I'm not convinced that specialised lab equipment or scentific methods is necessary for cold brew tbh.

Btw I used to love doing cold brew green tea in a similar way: get a large container, put a decent amount of green tea leaves in it (a smaller nut milk bag that is the size of a wallet or a bit bigger is really good for this, you can get them cheap online) and leave it overnight. Do not remove the tea leaves. When you pour a glass, refill the jug with more water and you can go like that for 3+ days, depending on how much you drink and how much tea leaves you add.

It's really good for the hot summer months, it's more delicate than hot-steeped green tea (that westoids almost invariably butcher by making it overly strong and using overly hot water) but it's nice.

Depending on how much you consume or how big your household is you might want to go for a 1L container or you might opt for like a 3L one. Whatever the case, you can absolutely wring every last cent out of your green tea leaves with this method and it's really minimal effort too.

16-20 hrs is pretty ideal unless you just want it very strong. Be sure to mix the grounds and water well (let the grounds 'bloom' with the water for a minute before sealing/covering). The grounds ideally will be on the course side and fairly fresh. 4-to-1 ratio of water to grounds is what I use. Medium to dark roast is good to get a strong flavor, and cold brewing doesn't extract much bitterness at all. In my personal experience more floral/fruity-forward beans/roasts don't work so well for my flavor preferences. I enjoy hot brew of fruity/floral beans, but as cold brew it's just not very appealing in my opinion.

If you can put the grounds in a bag or filter, it'll save a lot of time in the future when you might want to filter it so it's not like drinking sand or silt.

Also if you choose to filter, know that filtering can take a long time because the smaller grounds can clog up the pores. So go from filtering course to fine eg. use a sieve, then cheesecloth, then paper coffee filters, etc. based on how filtered you want it or your patience

Good