Every winery starts with a spreadsheet, and that is not a mistake. A spreadsheet is free, instantly editable and shaped exactly like the person who made it. The question is not whether Excel is good software — it is whether the thing you are doing is a calculation or a shared operational record.
What spreadsheets are genuinely good at
Ad-hoc calculation: a yield estimate, a dosage check, a costing scenario, a harvest plan you will throw away in October. One person, one moment, one answer. For these, a spreadsheet still beats any form-based system, and there is no reason to stop.
Where they fail in a cellar
Shared state. A cellar is many people recording events during the same week. Spreadsheets have no concept of who may write what, no enforced ordering and no protection against two versions of the truth. The failure shows up as a file named with a date and someone's initials.
Derived quantities. Vessel content, available litres, additive stock and bottled availability are not values — they are consequences of every movement recorded so far. In a spreadsheet they are cells someone must remember to update, which means the error is silent: a tank that reads 2,400 L when it holds 2,100 L looks exactly as trustworthy as a correct one.
Lineage. A LOT that splits into two, later blends with a third and gets bottled as one product is a graph. Spreadsheets represent graphs as columns of copied codes, and the copies drift. Once lineage drifts, traceability is gone and you will only find out when you need it.
Validation at the point of entry. Software can refuse a transfer into a barrel that cannot hold the volume, refuse an addition against a purchase lot that no longer has stock, and refuse a shipment larger than the bottles available. A spreadsheet accepts all three cheerfully.
Audit readiness. An inspection asks for a chain, not a table. Rebuilding one from several files, months later, costs days — and the answer you produce is only as good as the least careful copy-paste in the chain.
The signals you have outgrown it
More than one person records cellar work. You maintain a second file to reconcile the first. Someone asks for current vessel content and nobody answers immediately. You have discovered a discrepancy you could not explain. You are preparing for an audit or an e-label obligation. Or you have simply started to avoid asking questions because getting the answer is too expensive.
Choosing well, not just choosing
Dedicated software is worth it when it enforces the rules of a cellar rather than adding forms on top of it: quantities derived from movements, LOT identity that survives vessels, additive stock consumed from a specific purchase lot, bottled availability that only movements can change. If a system lets you type over a stock figure, it has the same failure mode as the spreadsheet you are leaving — with a subscription attached.
Keep the spreadsheets for thinking. Move the record of what actually happened somewhere it cannot quietly disagree with itself.