Brownies Lab1,221 recipes

Brownies Lab

Two overlapping styles in 1221 brownie recipes

Leave the recipe names aside and group the 1221 recipes by their 7 ingredient ratios alone, so that recipes built alike land together. Each group is named only by the numbers: the ingredients where its recipes sit furthest from the middle of all 1221.

The data splits best into two groups, but they overlap: a silhouette of 0.24, on a scale where 0 is no separation and 1 is complete. Read them as tendencies within one broad spread rather than separate kinds of brownie.

The recipes on one map

Every recipe, placed on the two directions along which the ratios vary most (a principal component projection). Close dots are recipes built alike. The lettered rings mark the middle of each group.

AB
Across →
More fat, sugar and egg to the right; 40% of the variation.
Up ↑
More chocolate, less cocoa and salt upward; 21% of the variation.

Along the first direction fat, sugar, egg and cocoa all rise together, each measured against the flour. A recipe sits far along it by using more of them or by using less flour, which the ratios cannot tell apart. The groups sit apart mostly along this direction.

The two groups

ALess fat and sugar

733 recipes · 60% of all 1221 · median oven 350°F (175°C), 30 min

Where it differs from all recipes

  • Fatmedian 100% vs 136% for all

    average rank: 33rd percentile of all recipes

  • Sugarmedian 176% vs 224% for all

    average rank: 34th percentile of all recipes

  • Eggmedian 100% vs 125% for all

    average rank: 35th percentile of all recipes

Its median recipe, at 100 g flour

Median recipe of group A in grams, against the median of all recipes
IngredientGroup AAll
Chocolate120 g150 g
Cocoa9 g18 g
Fat100 g135 g
Sugar175 g225 g
Egg100 g125 g
Leavening1 gnone
Salt0.5 g1 g

Each line is the group's median for that ingredient, scaled to 100 g of flour.

Closest to the middle of the group

BMore fat and sugar

488 recipes · 40% of all 1221 · median oven 350°F (175°C), 30 min

Where it differs from all recipes

  • Fatmedian 189% vs 136% for all

    average rank: 75th percentile of all recipes

  • Sugarmedian 316% vs 224% for all

    average rank: 73rd percentile of all recipes

  • Eggmedian 167% vs 125% for all

    average rank: 73rd percentile of all recipes

Its median recipe, at 100 g flour

Median recipe of group B in grams, against the median of all recipes
IngredientGroup BAll
Chocolate210 g150 g
Cocoa46 g18 g
Fat190 g135 g
Sugar315 g225 g
Egg165 g125 g
Leaveningnonenone
Salt2.5 g1 g

Each line is the group's median for that ingredient, scaled to 100 g of flour.

Closest to the middle of the group

How the groups are found

Each ratio is converted to a z-score (how many standard deviations a recipe sits from the mean), capped at 3 so one extreme recipe cannot claim a group, and k-means sorts the recipes into k groups, trying k from 2 to 4. Each k runs from 16 fixed starting points and keeps the tightest result, so the page is the same on every build. No group may hold fewer than 123 recipes.

The number of groups is the one with the best silhouette, which compares how close each recipe is to its own group with how close it is to the next one. By number of groups: 2 groups 0.24 · 3 groups 0.21 · 4 groups 0.19. At 0.25 or more the page calls the groups separate; from 0.18 to 0.25, overlapping; under 0.18, no clear styles.

A group's name lists the one to three ingredients where its recipes rank furthest from the middle of all 1221, on average. “More” and “less” are relative to the whole dataset, and the names say nothing about texture or taste, which the ratios alone do not show. The median recipe of a group is, like the typical recipe on the overview, the middle of each ingredient separately, not one real recipe. The recipes listed under each group are the ones nearest its center, at most two from any one site.