How much coffee should you buy at once?

Calibrate each purchase on 3 to 4 weeks of consumption at most. For an average drinker (2 filter cups per day = 15 g × 2 = 30 g/day), a 250 g bag lasts about 8 days; two 250 g bags cover a month. Avoid 1 kg bulk formats unless a family or shared office burns through it, to stay inside the optimal freshness window.

Calibrating each purchase is an equation between daily consumption and optimal freshness window. Specialty coffee holds full sensory qualities for 10 to 45 days after roasting (frequent peak between days 14 and 21). Beyond that, lipid oxidation brings measurable aroma loss. Buying more than 3-4 weeks of consumption mathematically guarantees that the last days will taste of decline. Golden rule: two 250 g bags spaced in time beat one 500 g bag bought in bulk.

Practical ratios by method. In filter (V60, Chemex, French press), the standard dose is 15-18 g for a 250 ml cup. An average drinker (2 cups/day) uses roughly 30-36 g/day, which is 210-252 g/week, or 840-1,000 g/month. In espresso, the dose is 18-22 g per double basket, yielding two 30-40 ml shots (or serving two people). A household pulling four espressos/day burns roughly 36-44 g/day, or 250-310 g/week, or 1-1.3 kg/month. In an Italian Moka, the typical dose is 20-25 g per 3-cup pot, leading to espresso-level consumption.

In Belgium, reference specialty formats are 250 g (most common), 1 kg for heavy espresso use, and occasionally 125 g or 200 g for rare microlots or discovery boxes. Monthly subscriptions from Brussels, Ghent and Antwerp roasteries typically ship 2 × 250 g or 1 × 500 g per month, meaning 125 g weekly rotation — well calibrated for a solo or couple setup.

Two traps to dodge. First: buying in bulk to save. A 1 kg bag at 50 €/kg costs 12.50 € per 250 g instead of 14-16 € at retail — a 15 % saving paid for in lost freshness. Unless turnover is high, the maths is unfavourable. Second: underestimating the guest effect. A weekend with friends can double a solo household's consumption, making the planned stock obsolete. The smart tactic is to keep one open bag (roasted 1-3 weeks ago) and one sealed backup in a cupboard, to be opened when the first drops to 10-15 g remaining — fluid rotation guaranteed.

Quantity to buy by consumption profile