Cold brew in bulk is coffee and water in a fixed ratio, steeped long and cold, filtered, and bottled. The ratio scales by percentage; what surprises people at scale is the water the grounds keep: wet grounds hold about twice their weight, so a fifth of what goes into the tank never comes out. Steep it in the cooler, filter it well, and keep the bottles cold from tank to shop fridge. Done this way, a cold brew maker that steeped a gallon jar makes about 620 bottles a run, and the cost of a 12-ounce bottle falls from $4.48 to $1.39. Below is the recipe at two sizes, the steps, the loss, what a bottle costs at each size, and a free scaling calculator.
The short version
- Write coffee and water as percentages: 7% coffee in the example.
- Steep cold, in the cooler, 16 to 20 hours.
- Wet grounds keep about twice their weight in water: plan for the loss.
- Filter well, then bottle cold.
- Cold brew is low in acid; keep it refrigerated, with a short date.
- Weigh what comes out and use your real loss to cost a bottle.
- TaroStack keeps the recipe by weight, takes each batch's ingredients off stock and checks its yield. More below.
The recipe, by percentage
Kaimana Cold Brew, the made-up cold brew maker on Oʻahu I use in these examples, steeped a gallon jar at a time before buying a brew tank. Its recipe, weighed:
| Ingredient | % of the mix | Kitchen batch, 8 lb | One batch, 600 lb | The run, 600 lb | Cost a lb, bought in bulk |
|---|---|---|---|---|---|
| Filtered water | 93% | 7.44 lb | 558.0 lb | 558.0 lb | $0.00 |
| Coffee, roasted and coarse ground | 7% | 0.56 lb | 42.0 lb | 42.0 lb | $5.44 |
| The whole mix | 100% | 8 lb | 600 lb | 600 lb |
The 600 pounds cost $228.48 in ingredients, all of it coffee at $12 a kilo; a bottle holds about 30 grams of coffee's worth. Ready to drink at 7%, not a concentrate to dilute. Starting the business is in how to start a cold brew coffee business.
The steps, at 600 pounds
- Grind coarse. Coarse and even, so it filters cleanly and doesn't over-extract.
- Fill the tank by weight. Filtered water and coffee at their percentages, stirred to wet every ground.
- Steep cold. In the cooler, 16 to 20 hours.
- Filter. Through the tank's filter, then a finer one, until clear.
- Weigh what comes out. Over three brews, about 22% of the weight stays in the grounds.
- Bottle cold. Into clean bottles, capped, and straight back into the cooler.
- Label with a lot code. Every bottle carries the brew's lot, the date and "Keep refrigerated".
A brew takes about 12.5 hours of labor, most of it filtering and bottling.
What a bottle costs at each size
| Per bottle | Kitchen batch, 8 lb | Bulk run, 600 lb |
|---|---|---|
| Ingredients | $1.08 (grocery prices) | $0.37 (bought in bulk) |
| Packaging | $0.90 | $0.62 |
| Labor at $20 an hour | $2.50 (7.5 min a bottle) | $0.40 (1.2 min a bottle) |
| Cost of a bottle | $4.48 | $1.39 |
Coffee by the kilo from a roaster cuts the ingredients by two-thirds, and the labor falls from 7.5 minutes a bottle to about 1. The bottle, cap and label are almost half a bottle's cost; what a roaster earns on the same beans is in coffee business profit margin. When a co-packer makes more sense, and the choice between refrigerated and shelf-stable, is in cold brew co-packer.
Why it stays cold
Cold brew is a low-acid drink, and a sealed bottle of a low-acid drink kept warm is where dangerous bacteria can grow. So refrigerated cold brew is kept cold from the tank to the shop fridge, with a short date; shelf-stable cold brew is a different product, made under FDA's rules for low-acid canned foods, which is why a small maker often sends it to a co-packer.
Get the calculator
Download the cold brew scaling calculator. Two sheets: scale the recipe, where you type each ingredient's percentage and cost a pound and the raw mix you want, and each ingredient's weight for the run fills in, with the brews, what comes out after the grounds loss, the bottles it fills and the cost of each bottle; and weigh the loss, where what went in and came out over a few batches gives your average grounds loss. It's an ordinary Excel file with no macros, and it works in Google Sheets, LibreOffice and Numbers.
Where this stops working
A house blend and a decaf, brews three times a week, coffee from two roasts, and cafés that reorder by text. A sheet can say how much coffee a brew needs, but not which roast went into which bottle, or how many bottles are near their date.
How TaroStack does it
TaroStack keeps the recipe by weight, takes each batch's ingredients off stock and checks its yield.
The recipe in the units you use. A recipe holds each ingredient by weight, with coffee bought by the kilo and used by the gram, and the cost of every bottle comes from what you paid. "What could I make right now" says how many runs the coffee and bottles on the shelf allow.
Each run a batch. A run takes its ingredients off stock, records the lots of coffee it used, and gets a lot of its own for the bottles, with how much came out good, how much was rejected and the labor minutes.
Yield checked from history. From your own batch history, TaroStack says whether a recipe yields what it claims and which ingredient's quantity is off, so a grounds loss that creeps up shows in the numbers. A case of bottles that warmed up in transit is an adjustment with its reason, spoiled, and shows in the waste report.
| The job | Spreadsheet | In TaroStack |
|---|---|---|
| Ingredients for Monday's run | Multiply, then check the shelf | What could I make right now |
| Which roast went into a run | Not written down | Lots recorded on the batch |
| The real grounds loss | Weighed now and then | Good and rejected on every batch |
| Bottles that warmed in transit | Thrown out, forgotten | Adjustment with a reason |
Recipes, batches, lots and yield are on every plan, from $49 a month. The first 30 days are free, with no credit card. If you'd like a hand setting up, ask, and we'll do it with you.