How Much Green Coffee Should a Micro-Roastery Buy Per Batch?

Buy too little and you’re placing orders every other week, paying shipping costs that eat your margin. Buy too much and you’ve got green coffee sitting in a bag past its prime, tying up cash you needed for something else. Neither one is a rounding error at micro-roastery scale — both show up directly in your margin.

Here’s how to actually think about the number, instead of guessing.

Start With What You Roast, Not What’s Available

Work backward from your real roasting cadence: how many kilos go into your roaster per week, across every account and bag you sell. That’s your baseline. The order size question isn’t “what’s the smallest bag I can buy” — it’s “what will I actually turn into roasted coffee before the next reorder makes sense.”

Green Coffee Doesn’t Last Forever, Either

Green coffee stores far longer than roasted coffee — that’s real, and it’s one of the reasons buying green in the first place makes sense for a small operation. But “far longer” isn’t “indefinitely.” Quality still drifts over months in storage, especially if humidity and temperature aren’t controlled. Buying six months of inventory in one order isn’t playing it safe — it’s just moving the freshness problem from your shelf to your storage room.

Build in a Buffer, Not a Warehouse

A reasonable buffer — enough to cover a slow shipment or a busier-than-expected week — is smart. A buffer sized like a hedge against every possible disruption is capital you can’t use for anything else. Most micro-roasteries do better ordering more frequently in smaller amounts than trying to front-load a quarter’s worth of green coffee in one purchase.

The Real Constraint: Minimum Order Size

None of this matters if the minimum order from your supplier doesn’t match your actual math. The standard green coffee bag in international trade is 60-70kg — a volume built for importers filling a warehouse, not a roastery buying five kilos a week for a handful of café accounts. If your real number is smaller than the minimum you’re being offered, you’re not solving a roasting problem, you’re solving a supplier problem.

That’s the whole reason Tostar Café sells green coffee in 5kg, 10kg, and 20kg formats instead of forcing a 60kg minimum on a roastery that doesn’t need it. See wholesale sizes →