---
name: "sourdough_basics"
description: "Sourdough baking end to end: starter care, feeding ratios and bake-day scheduling, shaping and scoring technique, and troubleshooting. Triggers on sourdough starter questions, feeding schedules, hydration ratios, loaf shaping, scoring for an ear, Dutch oven bake times, or sourdough troubleshooting."
metadata: { "includeInPrompt": true }
---

# Sourdough Basics

## Purpose

Get someone from zero to a baked loaf: keep a starter alive, plan feeds with
real ratios, run a bake-day schedule, shape and score properly, and fix what
goes wrong. Aimed at beginners; every number in the references is sourced from
published baking guides, not invented.

## Workflow

1. **Starter check.** If the user has a starter, find out how it is stored
   (counter vs fridge) and how often they bake. If they are starting fresh or
   reviving a dormant one, point them at the revival routine: 2-3 room-temp
   1:1:1 feeds 10-12 hours apart until it doubles in 4-6 hours.
2. **Feeding plan.** Pick a ratio from `references/feeding-ratios.md` based on
   their kitchen temp and schedule. Use `bin/feed_ratio.py` to compute the
   grams: `python3 bin/feed_ratio.py <starter_g> <ratio> [--temp warm|room|cool]`.
   Bake days start with the starter at peak: domed, doubled, not collapsed.
3. **Bake-day schedule.** Give them the timeline in
   `references/bake-day-schedule.md`, adjusted for their kitchen. Same-day bake
   exists for impatient bakers; the overnight cold proof gives better flavor
   and easier scoring.
4. **Shape and score.** Walk through pre-shape, bench rest, final shape, then
   scoring from `references/shaping-scoring-troubleshooting.md`. Score cold
   dough straight from the fridge with a sharp blade.
5. **Bake and cool.** Dutch oven method: preheat 45-60 min at 450-480F, lid on
   20 min, lid off 20 min at ~430F, internal temp 205F. Cool at least 1 hour
   before slicing.
6. **Troubleshoot.** Match their symptom to the troubleshooting section before
   suggesting random changes. One variable at a time.

## Output Contract

- When asked for a feeding plan: starter grams to keep, flour and water grams,
  ratio used, and expected peak window with the kitchen temp stated.
- When asked for a bake schedule: a concrete timeline with times they can
  follow, plus what "done" looks like at each stage (not just clock times).
- When asked about a failure: name the likely cause from the references, the
  one fix to try first, and what to watch next bake. No shotgun advice.
- Never invent numbers. If a number is not in the references, say so and
  frame it as an estimate.

## Operating Rules

1. Ratios are always by weight. If someone feeds by volume, tell them to get
   a kitchen scale; volume feeding is the top source of erratic starters.
2. 100% hydration (equal flour and water by weight) is the default. Do not
   suggest stiff or liquid starters unless asked.
3. Watch the dough, not the clock. Every schedule is a template at ~68F;
   adjust by reading the starter's peak and the dough's rise, never by
   following times blindly.
4. Bread flour or all-purpose flour is fine for feeding and baking. Whole
   grain flours ferment faster and need watching.
5. Do not promise ears, open crumb, or any outcome. The skill teaches
   technique; results take practice loaves.
6. Keep SKILL.md as the operational core. Bulky tables, schedules, and
   troubleshooting live in `references/`. The calculator in `bin/` is the
   only code; keep it that way.