Tools

An Afinador is not a calculator

There is one true calculator on this shelf: the brine one. You tell it how much water and what percentage of salt you want, and it returns the grams. Always the same result, always exact. There is nothing to predict — salt dissolves the same in January as in August.

An Afinador — Spanish for “tuner” — does something else. You tell it where the jar will live and how you want it to taste, and it proposes a formulation with its dates. Behind it there is no rule of three: there is a model of how that ferment behaves — how fast it eats the sugar, how temperature changes it, when it stops being sweet water and starts being something else.

And that is why an Afinador does something a calculator never does: it tells you when it is not sure. It warns you that at 31 °C it is outside what it knows. It tells you that a combination will run out of fizz before you make it. It explains the trade-off it had to make to get where you asked.

A number without context is not an answer. A proposal that explains itself is.

Why there is one per ferment

It would be more convenient to have a single one with a dropdown on top. We do not, and it is not laziness about merging them: they do not share mathematics.

Kombucha consumes sugar at a fairly steady rate, and what drives the speed is how much starter you add. Water kefir consumes in an S shape — slow, then all at once, then slow again — and what drives it is how many grains there are and how warm they sit. One is measured in days; the other in hours. One warns about overshooting; the other also about falling short.

Putting them in the same tool would mean either building two tools pretending to be one, or settling for an average that serves neither well. So there is one per ferment, and they appear one at a time.

They come out slowly, on purpose

The interface of an Afinador is built in an afternoon. What takes time is what sits behind it: reading what has been published about that ferment, turning it into coefficients, and checking it against fermentations whose outcome we already know. That takes weeks, and sometimes measuring things nobody has measured.

We publish an Afinador when the model survives that check, not when the screen is ready. That is why there are three and not twelve, and why the ones that exist say out loud what they are not sure about. Behind them come vinegar, pickles, sauerkraut and kimchi, in that order.

The tools calculate assuming the temperature of your home never changes. It does — it drops at night, rises when you turn the oven on, shifts with the season.

That is what the mentor does and a tool cannot: accompany the batch while it happens, move the window when you taste it, and explain, when you close it, why it came out the way it did.