Pumpkin Bread Lab142 recipes

Pumpkin Bread Lab

Two overlapping styles in 142 pumpkin bread recipes

Leave the recipe names aside and group the 142 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 142.

The data splits best into two groups, but they overlap: a silhouette of 0.19, 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 pumpkin bread.

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 pumpkin, fat and spice to the right; 33% of the variation.
Up ↑
More salt and sugar, less leavening upward; 17% of the variation.

Along the first direction pumpkin, fat, spice, sugar, 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 pumpkin

82 recipes · 58% of all 142 · median oven 350°F (175°C), 55 min

Where it differs from all recipes

  • Pumpkinmedian 101% vs 127% for all

    average rank: 33rd percentile of all recipes

  • Fatmedian 46% vs 50% for all

    average rank: 38th percentile of all recipes

  • Spicemedian 2% vs 2.4% for all

    average rank: 38th percentile of all recipes

Its median recipe, at 250 g flour

Median recipe of group A in grams, against the median of all recipes
IngredientGroup AAll
Pumpkin255 g315 g
Sugar250 g285 g
Fat115 g125 g
Egg115 g115 g
Spice5 g6 g
Leavening7 g9 g
Salt3.5 g3.5 g

Each line is the group's median for that ingredient, scaled to 250 g of flour.

Closest to the middle of the group

BMore pumpkin and fat

60 recipes · 42% of all 142 · median oven 350°F (175°C), 58 min

Where it differs from all recipes

  • Pumpkinmedian 157% vs 127% for all

    average rank: 73rd percentile of all recipes

  • Fatmedian 57% vs 50% for all

    average rank: 66th percentile of all recipes

  • Spicemedian 3.1% vs 2.4% for all

    average rank: 66th percentile of all recipes

Its median recipe, at 250 g flour

Median recipe of group B in grams, against the median of all recipes
IngredientGroup BAll
Pumpkin395 g315 g
Sugar325 g285 g
Fat145 g125 g
Egg125 g115 g
Spice8 g6 g
Leavening10 g9 g
Salt4 g3.5 g

Each line is the group's median for that ingredient, scaled to 250 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 15 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 0.19 · 3 groups 0.17 · 4 groups 0.16. 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 142, 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.