The pastry shop that watched butter eat the croissant's margin

The numbers that stopped adding up

Pastelaria Flor de Sal, in Ponte da Ribeira, has lived off croissants since Mr. Norberto opened the shop twenty-two years ago. It's the best-seller, the one customers ask for by name, the one that carries the rest of the window. At the year-end review, his daughter Inês, who handles the books, noticed something odd: the croissant's margin had dropped from around 38% to 24% — with no change to the recipe, the supplier, or the oven.

"It made no sense at all," said Mr. Norberto. "We were still selling at the same price, making the same recipe. It was just the numbers that no longer added up."

Our heroes

An invisible increase, sliced into small pieces

There was no fraud and no accounting mistake. Butter had simply gone up in price — but not all at once, in a jump anyone would notice. It rose in small slices, invoice by invoice, over six months: a few cents here, a few cents there, always within what looked like a supplier's normal variation. Nobody kept the old invoices next to the new ones to compare — why would they, when each increase on its own alarmed no one?

It was only when Inês placed January's invoice next to June's that the two numbers, side by side, told the whole story: butter up 42%, without anyone noticing it happen.

How the Top 10 Price Change ranking catches this on its own

Pastelaria Flor de Sal had already been logging ingredient prices in Mise en Place for over a year — mostly to know the cost of each pastry, not to watch suppliers. It was by opening the "Analysis" tab and clicking "Top 10 Price Change" that Inês saw, without comparing a single invoice by hand, the list ranked from biggest to smallest increase: Butter, +42%, right at the top — far ahead of any other ingredient in the shop.

There was no need to guess where to look or rebuild six months of invoices: the app already had every price saved, and all it took was asking "what went up the most?"

Back to the margin it should have

With the number staring right at him, Mr. Norberto already knew who to talk to and about what: he closed a bigger deal with Mrs. Alzira, at a better price per kilo, and adjusted the croissant's price slightly for the first time in three years. At the next review, margin was back near 36%.

Today, "Top 10 Price Change" gets checked every month at Pastelaria Flor de Sal — not waiting for another scare at year-end, but to catch the next sliced-up increase before it reaches forty percent.

"Top 10 Price Change" is part of the Mise en Place app, where Pastelaria Flor de Sal also organises its ingredient catalogue, calculates the cost of every pastry, and sees the evolution of any price on a chart — all from the same history.