Peanut Butter Cookies Lab326 recipes

Peanut Butter Cookies Lab

Two overlapping styles in 326 peanut butter cookie recipes

Leave the recipe names aside and group the 326 recipes by their 6 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 326.

The data splits best into two groups, but they overlap: a silhouette of 0.21, 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 peanut butter cookie.

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 sugar, peanut butter and butter to the right; 35% of the variation.
Up ↑
More salt and butter, less leavening upward; 19% of the variation.

Along the first direction sugar, peanut butter, butter, egg and leavening 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 sugar and butter

164 recipes · 50% of all 326 · median oven 350°F (175°C), 11 min

Where it differs from all recipes

  • Sugarmedian 90% vs 111% for all

    average rank: 30th percentile of all recipes

  • Buttermedian 52% vs 61% for all

    average rank: 34th percentile of all recipes

  • Peanut buttermedian 75% vs 88% for all

    average rank: 35th percentile of all recipes

Its median recipe, at 190 g flour

Median recipe of group A in grams, against the median of all recipes
IngredientGroup AAll
Peanut butter145 g170 g
Butter100 g115 g
Sugar170 g210 g
Egg50 g55 g
Leavening4 g5 g
Salt1.5 g1.5 g

Each line is the group's median for that ingredient, scaled to 190 g of flour.

Closest to the middle of the group

BMore sugar and butter

162 recipes · 50% of all 326 · median oven 350°F (175°C), 11 min

Where it differs from all recipes

  • Sugarmedian 134% vs 111% for all

    average rank: 70th percentile of all recipes

  • Buttermedian 72% vs 61% for all

    average rank: 66th percentile of all recipes

  • Peanut buttermedian 113% vs 88% for all

    average rank: 65th percentile of all recipes

Its median recipe, at 190 g flour

Median recipe of group B in grams, against the median of all recipes
IngredientGroup BAll
Peanut butter215 g170 g
Butter140 g115 g
Sugar255 g210 g
Egg60 g55 g
Leavening6 g5 g
Salt2 g1.5 g

Each line is the group's median for that ingredient, scaled to 190 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 33 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 0.21 · 3 groups 0.16 · 4 groups 0.14. 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 326, 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.