Sam Rivera

It started with a bad pizza.

Not bad in the sense that it was inedible — bad in the sense that it was inconsistent. One weekend the crust would blister beautifully, the next it'd come out dense and pale. Same recipe, same oven. Different results. That bothered me in the way only an engineer can be bothered by unexplained variance.

The Baker's Percentage Rabbit Hole

The breakthrough came when I discovered baker's percentages — a way of expressing every ingredient as a ratio relative to the total flour weight. Flour is always 100%. If your dough is 65% hydration, you use 650g of water for every 1000g of flour.

This sounds simple until you realize it unlocks everything: you can scale recipes up or down without recalculating, compare recipes across styles, and isolate exactly which variable changed when something goes wrong.

I built the first version as an Excel workbook with a handful of input cells:

Flour weight (g)
Hydration %
Salt %
Yeast type (instant, active dry, fresh) and ambient temperature
Fermentation style (room-temp, cold, poolish/biga pre-ferment)

The workbook outputs per-ball weights, a fermentation window estimate, and a "temperature adjustment factor" so the same recipe works whether it's a 68°F kitchen or an 80°F summer day.

What I Learned About Spreadsheets

Building a calculator that other people actually use taught me more about UX than most software projects. Named ranges, color-coded input cells, protected formula cells, and embedded instructions all matter when your user is covered in flour and squinting at a screen.

I eventually rewrote it as a web app (React + TypeScript) so I could share links rather than email .xlsx files. But the Excel version still lives on — sometimes a local file you can annotate beats a polished web app.

You can grab both versions on the Projects page.