The half gallon that never comes out
Two pounds of grounds is 907 grams. At 2.2 grams of water held per gram of coffee, the spent bed keeps 1,996 grams — a little over half a gallon out of the three you poured. That is 17.6 percent of the batch, gone before anything is filtered.
Take another three percent for what wets the filter and clings to the vessel and the concentrate comes to 9,080 grams, or 2.40 gallons. Eighty percent of what went in. Every ratio-based cold brew recipe on the internet describes the batch going in and almost none of them mention this.
Ice is not free volume
A sixteen ounce iced cup holds sixteen ounces of cup, not sixteen ounces of drink. Fill it with ice and eleven ounces of liquid is a fair figure — measure your own, because cube size changes it more than people expect. Diluted one to one, 2.40 gallons of concentrate becomes 4.80 gallons finished, which is 614 ounces, which is 55 cups at eleven ounces each.
Work the same batch at sixteen ounces of liquid per cup and you get 38 cups. The difference between those two numbers is entirely an ice assumption, and it is the reason two cafes with identical recipes disagree about what a batch yields.
Where the money lands
Two pounds at 9.50 is 19 dollars. Six dollars of filters, water and the time to build and strain it makes 25. Over 55 cups that is 45 cents a cup of coffee and supplies — before the cup itself, the lid, the straw and the ice, none of which are in it.
At 5.25 a cup the batch takes 288.75 and the coffee side of it is 8.7 percent. Cold brew is cheap to make and expensive to sell, which is exactly why it is on the menu, and also why the yield question is worth getting right: a batch that gives 45 cups rather than 55 moves the cost per cup by 11 cents without anything visible changing.
Pressing the bag
Half a gallon of liquid sitting in the grounds is nine more cups at this dilution, and there is a real temptation to squeeze it out. Some of it does come back if you press or spin the bag. What comes back is not the same liquid as what drained freely, because the last of what a bed holds carries different things out of the coffee than the first of it, and whether that is a trade worth making is a tasting decision rather than an arithmetic one.
What the arithmetic can do is tell you what is at stake before you decide. Nine cups a batch, five batches a week, is 45 cups — call it 236 dollars of takings a week that is currently in the bin.
Questions people ask
How much concentrate does a cold brew batch actually yield?
Less than the water you poured, by a lot. Two pounds of grounds hold about two and a fifth times their own weight in water, so a three gallon batch loses roughly half a gallon to the spent bed and another few percent to the filter and the vessel. The defaults here give 2.40 gallons of concentrate from three gallons of water, which is eighty percent.
How much water do cold brew grounds retain?
Worth weighing rather than assuming, because it moves with the grind and with what you do to the bag. Weigh the spent bed wet, subtract the dry grounds, divide by the dry grounds. A bag lifted out and left to drip holds considerably more than one that has been pressed, and that difference is worth several cups a batch.
How many cups do I get from a cold brew batch?
It depends on the ice as much as on the coffee. A sixteen ounce cup with five ounces of ice holds eleven ounces of liquid, so 2.40 gallons diluted one to one gives 55 cups. Assume the cup holds sixteen ounces of drink and the same batch reads 38. Measure your own cup with your own ice before trusting either.
What does a cup of cold brew cost to make?
With the defaults, 45 cents — two pounds of coffee at 9.50 plus six dollars of filters, water and labour, over 55 cups. That is coffee and batch supplies only. The cup, lid, straw and ice are not in it and neither is anything past the strainer, so the real cost of goods is higher.
Should I squeeze the cold brew bag to get more out?
The page tells you what is at stake and not what to do. Half a gallon in the bed is about nine more cups at a one to one dilution, which is real money over a week. What comes out under pressure is not the same liquid as what drained freely, though, so it is a tasting decision. Nothing here has an opinion on how you would go about it.