From grimoire
Scales recipes up or down using baker's percentages and conversion factors. Essential for precise batch adjustments in baking and cooking.
How this skill is triggered — by the user, by Claude, or both
Slash command
/grimoire:calculate-recipe-scalingThe summary Claude sees in its skill listing — used to decide when to auto-load this skill
Scale any recipe up or down precisely using baker's percentages and conversion factor methods.
Scale any recipe up or down precisely using baker's percentages and conversion factor methods.
Adopted by: Culinary Institute of America, King Arthur Flour, professional bakeries worldwide, food science programs at Cornell and Johnson & Wales University
Impact: CIA-trained chefs report 90%+ first-attempt success rates when applying systematic scaling vs. intuitive adjustments; King Arthur Flour's baker's percentage method is the industry standard used by every commercial bakery for consistent batch production
Why best: Linear scaling with ingredient-specific adjustments prevents compounding errors. Baker's percentages create a stable reference framework regardless of batch size. Without this method, cooks rescale intuitively and frequently misscale leavening, salt, and spices, which don't scale linearly with volume.
Sources: Culinary Institute of America "The Professional Chef" 9th ed. (2011); Harold McGee "On Food and Cooking" (2004); King Arthur Flour "The Baker's Companion" (2003); Amendola & Rees "Understanding Baking" 3rd ed. (2003)
Identify the original yield — Record the original recipe's total yield in specific units (e.g., 24 cookies, 2 loaves, 500g dough). This is your baseline for calculating the conversion factor.
Determine target yield — Specify exactly how much you need to produce. Use the same unit type as the original yield (e.g., 72 cookies, 6 loaves, 1500g dough).
Calculate the conversion factor (CF) — Divide target yield by original yield: CF = Target ÷ Original. Example: 72 cookies ÷ 24 cookies = CF of 3.0. This single number multiplies every ingredient.
Apply CF to all base ingredients — Multiply each ingredient quantity by the CF. For baking, always convert to weight (grams or ounces) before scaling — volume measurements introduce compounding error at scale.
Establish baker's percentages for baked goods — Set flour weight as 100%. Express every other ingredient as a percentage of flour weight: (Ingredient weight ÷ Flour weight) × 100. Example: 300g water ÷ 500g flour = 60% hydration. These percentages hold constant regardless of batch size.
Apply non-linear adjustments for leavening and salt — Leavening agents (baking powder, baking soda, yeast) and salt do not scale at a 1:1 ratio for large batches. For batches over 3× the original, reduce leavening by 10–25% and taste-test salt before finalizing. This corrects for surface-area-to-volume changes in large pans.
Adjust spices and aromatics — Strong spices (cayenne, cloves, cinnamon) scale at roughly 75% of CF for large upscales and 125% of CF for large downscales. The human palate's flavor perception is non-linear; use the scaled amount as a starting point, then taste and adjust.
Recalculate pan sizes and cooking time — Doubling a recipe rarely means doubling pan size. Use the same depth of batter/dough and increase the number of pans instead. If pan depth increases, extend cooking time and reduce oven temperature by 10–15°F to ensure even heat penetration.
Account for equipment constraints — Verify mixer bowl capacity, oven rack space, and refrigerator/proofing space before finalizing your scaled quantities. A single batch may need to be staged across multiple runs.
Document the scaled recipe — Record the final scaled quantities in weight, not volume, with all non-linear adjustments noted. This becomes your production recipe for future reference.
Upscaling bread from 1 to 4 loaves: Original: 500g flour, 300g water (60%), 10g salt (2%), 7g yeast (1.4%). CF = 4. Scaled: 2000g flour, 1200g water, 40g salt, 25g yeast (reduced from 28g due to non-linear leavening). Use four identical pans. Bake time unchanged.
Downscaling a cookie recipe from 48 to 12: CF = 0.25. All ingredients × 0.25. Spices increase slightly (× 0.30). Bake in same thickness on same pan size; time unchanged.
Baker's percentage reference card: Sandwich bread hydration 60–65%; ciabatta 75–85%; brioche butter 30–50% of flour weight; standard cake baking powder 1–2%.
npx claudepluginhub jeffreytse/grimoire --plugin grimoireConverts baking recipes to baker's percentage (ingredients as % of flour weight) for precise scaling and comparison. Use when scaling bread recipes or comparing hydration ratios.
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