At Stoble, we use a 1:4 ratio of coffee to water for our cold brew. If you don’t have a cold brewer a french press does the trick quite well.
Cold brew scales up very well so we will give you a recipe for one cup but feel free to use more coffee and just use the same ratios for a bigger batch.
Step 1: Start with 40 grams of coffee ground coarse (similar to ground peppercorn). Pour these grounds into your container.
Step 2: We cheat a little bit when brewing our cold brew and actually use hot water for a portion of the brewing process. We split our water into halves and add half of it hot and half of it cold.
Step 3: So your first pour will be 80 grams of hot water into the grounds, stir it and let it sit for at least 1 minute. Then add the last 80 grams of cold water to the slurry and store refrigerated for 18-24 hours.
Step 4: When it is done brewing strain the grinds and you have successfully made your cold brew concentrate.
Step 5: Now you can dilute it to taste. Start by adding double the weight of concentrate in water to dilute. So in this case you will get about 80 grams of concentrate from this batch because the grounds will absorb about 80 grams of water and leave you with 80 grams of liquid. So add 160 grams of water and taste. If it’s too strong add a little more till it tastes right to you. Just make notes about how you like it and what ratios you like so you can stay dialed in every time. Also, always use filtered water for brewing and concentrate brewing for best results.