Working out how much green coffee to buy sounds straightforward until you start accounting for roast loss, changing sales volumes, wholesale commitments and the different rates at which coffees move through a range.
For a commercial roastery, ordering the right quantity is important. Too little can leave you short of a core coffee halfway through a production cycle. Too much can leave cash sitting in bags of coffee that may take months to use.
The most useful place to start is not with how much green coffee you can store, but with how much roasted coffee you actually need to produce.
Start With Your Roasted Coffee Sales
Look at how many kilograms of roasted coffee you sell during a typical week or month.
Use actual sales where possible rather than relying on what you expect to sell. It can also help to separate regular demand from occasional orders.
- 60kg per week committed to wholesale customers
- 20kg per week sold online
- 10kg per week sold through your own café
- Additional volume required for subscriptions, events or seasonal orders
That gives a much better starting point than simply deciding to purchase a certain number of sacks.
If sales fluctuate considerably, look at several months rather than basing purchasing on one particularly busy or quiet period.
Allow For Weight Lost During Roasting
A kilogram of green coffee does not produce a kilogram of roasted coffee.
Coffee loses weight as it roasts, largely through the loss of water and other volatile material. The exact amount varies according to the coffee and roast profile, so your own production records are more useful than applying one fixed percentage to every batch.
Suppose a roastery records an average roast loss of 15%.
If it needs 100kg of finished roasted coffee, buying 100kg of green coffee will leave it short.
The calculation would be:
100kg ÷ 0.85 = approximately 117.6kg of green coffee.
That difference matters when you are costing coffee and planning larger production volumes.
Record the green weight and finished roasted weight of regular batches. Over time, this gives you a reliable figure for each coffee or roast profile rather than relying on an industry average.
Calculate Requirements For Each Coffee
Total production volume only tells part of the story.
A roastery producing 200kg each week may use several different coffees, and they are unlikely to sell at the same rate.
A house espresso blend might account for 120kg, while a seasonal filter coffee sells 10kg. Those coffees should not be purchased on the same basis simply because they sit in the same range.
For blends, calculate the requirement for each component.
If a blend uses 60% Brazilian coffee and 40% Colombian coffee, for example, the amount required from each origin can be worked out from the expected production volume.
This is particularly important for a core blend. Running out of one component can interrupt production even when plenty of the other coffees remain in stock.
Include Wholesale Commitments
Regular wholesale customers make part of your demand relatively predictable.
If several cafés collectively order 80kg every week, that volume should be accounted for before estimating less predictable online or retail sales.
This becomes increasingly important as a roastery grows its trade business. A new wholesale account taking 20kg a week adds more than a tonne of roasted coffee to annual production if those orders continue throughout the year.
A change that looks fairly small on a weekly production sheet can therefore make a noticeable difference to green coffee requirements.
Known commitments should be included as soon as they are confirmed rather than waiting until stock begins moving more quickly.
Leave Room For Test Roasts And Quality Control
Not every kilogram entering the roastery will become saleable finished coffee.
New coffees may need several test roasts before a production profile is settled. Samples may also be required for cupping, staff training, wholesale prospects or quality checks.
The quantities involved may be small, but repeatedly ignoring them can make stock figures inaccurate.
This is particularly relevant when introducing several new coffees at once or working with a limited quantity of a particular lot.
Treat Core And Seasonal Coffees Differently
A coffee used every week throughout the year can justify a different purchasing approach from a limited seasonal release.
Core coffees normally need enough cover to protect regular production. You have sales history to work from and can make a more confident estimate of future usage.
Seasonal coffees are less predictable.
Buying heavily into an unfamiliar coffee because you expect it to sell well can leave you with stock long after customer interest has moved elsewhere. Starting with a smaller quantity gives you a chance to see how it performs before increasing the commitment.
The same principle applies when trialling an unfamiliar origin or adding another coffee to an already large range.
Build In A Sensible Buffer
Buying exactly the calculated amount leaves no room for an unexpected wholesale order, delayed delivery or busier-than-normal week.
That does not mean keeping months of unnecessary stock.
A useful buffer should reflect how quickly the coffee sells and how easily it can be replenished. A high-volume blend component may need more protection than a coffee used occasionally for filter orders.
Supplier lead time matters here. If replacement stock can be obtained quickly, there may be little reason to hold a large surplus purely as insurance.
Review The Numbers As The Roastery Changes
Green coffee requirements should change with the business.
If average weekly production moves from 100kg to 150kg, purchasing should adjust with it. The same applies if a major wholesale account is won or lost, a blend changes, or a seasonal product is removed from the range.
Reviewing actual usage also exposes differences between forecasts and what is really happening.
A coffee expected to sell 20kg a week may consistently sell 12kg. Another may be moving twice as quickly as planned. Future orders can then be adjusted before either becomes a stock problem.
Buy For What You Actually Roast
There is no single order quantity that is right for every roastery.
A useful purchasing figure comes from knowing how much finished coffee you need, accounting for roast loss, breaking that requirement down by coffee and allowing a sensible margin for normal changes in demand.
As production grows, those calculations become more important. A few kilograms either way may make little difference to a very small operation, but the same forecasting errors repeated across several coffees can become expensive at commercial scale.
Good purchasing starts with the production figures you already have. Use them to decide what needs ordering rather than allowing the size of the order to dictate what you have to roast.