The best way to ensure that your cold brew is ready when you want it is to use a scale and measure out how much coffee and water you need for each batch (so that you're always getting the same amount).
If you like your coffee on the stronger side, and don't mind a little bit of acidity, then by all means go ahead and leave the coffee to steep in there for as long as you like!
Coffee to Water Ratio
The water to coffee ratio in the cold brew process is generally 1:4, or even 1:3 for a stronger cold brew. You can, however, adjust this ratio to make cold brew stronger or weaker depending on your taste.
How to Store Cold Brew
We recommend storing your cold brew coffee in an airtight container in the refrigerator. The best time to drink cold brew is within 24 hours of making it, but that doesn't mean the coffee won't be good after that time period.