Everyone can calculate pour cost. The hard part is knowing it changed.

That is the whole thing. Four numbers you already have. A full cocktail adds mixers, juice and a second spirit, so there are more lines, but the arithmetic never gets harder than this. Nobody is stuck here.

Twenty percent was true on the day you worked it out. Then the invoices kept coming.

A case price goes up a dollar at the next delivery. A pack size drops from twelve to ten at the same shelf price, which is a cost increase that does not look like one. Your usual bourbon runs out on a Friday and someone pours whatever is on the shelf, at a different cost, and the drink still goes out at $9.

None of that is a mistake. It is what a week in a bar looks like. The number was right in January, nobody did anything wrong in between, and it is March now.

Your pour cost is not really a number, it is a number hanging off other numbers, and when one of those changes, every drink built on it is quietly wrong until somebody notices.

Nothing announces that. The invoice does not say which recipes it just changed. The register does not know the bottle got more expensive. The delivery gets put away and the price on the menu stays where it is.

So finding out means working backwards: pull every invoice since you last checked, sort out which costs actually changed, trace each of those through every recipe and pour size that touches it, and hold the result against what you are charging tonight. For one spirit that is a chore. Across a full bar it is a project, and it is a project with no obvious day to do it on, so it competes with running the bar and loses.

So most owners are not walking around with a wrong number. They are walking around with a number they have no way to check, which is worse. A wrong number you know is wrong gets fixed. A number you cannot verify just sits there.

Say you did all of that anyway. You would be holding a pile of changes, and nearly all of them mean nothing.

A bottle up eleven cents does not move a $9 drink. Neither does a pack size on something you pour twice a month. Chase every one of those and you have invented a second job watching numbers twitch. Chase none of them and the one that mattered goes past with the rest.

That call is the part that never makes it into the formula, and it is the difference between a system that helps and a system that shouts. Knowing something changed is not worth much on its own. Knowing it changed enough is.

We think a cost change should find you, rather than wait for you to go looking. So we took on all three: the inputs, the redo, and the call about whether it matters.

Every invoice that comes in updates what a bottle actually costs. Every pour built on that bottle gets worked out again against what you charge today, so nothing sits waiting for a month end. And we hold the result against the margin you set, so what reaches you is the handful that changed enough to be worth your attention, not a list of everything that shifted a cent.

There is no report to sit down with. When a pour drifts off your margin, that pour comes to you, with the new cost, the price you are charging, and what the price would have to be. You say yes or no. Nothing reaches your register until you do.

Part of why nothing catches this on its own is that your POS was never built to watch it in the first place. And a tool that hands you the finding and stops is the wrong shape for the job.