Potato Bread Lab100 recipes

Potato Bread Lab

Two overlapping styles in 100 potato bread recipes

Leave the recipe names aside and group the 100 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 100.

The data splits best into two groups, but they overlap: a silhouette of 0.25, 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 potato 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 sugar, fat and egg to the right; 36% of the variation.
Up ↑
More potato, yeast and salt upward; 19% of the variation.

Along the first direction sugar, fat and egg 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, little or no egg

58 recipes · 58% of all 100 · median oven 400°F (205°C), 35 min

Where it differs from all recipes

  • Fatmedian 4.9% vs 8.5% for all

    average rank: 32nd percentile of all recipes · none in 37% (all recipes 22%)

  • Eggmedian 0% vs 6.8% for all

    average rank: 31st percentile of all recipes · none in 81% (all recipes 47%)

  • Sugarmedian 0% vs 3.1% for all

    average rank: 33rd percentile of all recipes · none in 51% (all recipes 31%)

Its median recipe, at 450 g flour

Median recipe of group A in grams, against the median of all recipes
IngredientGroup AAll
Potato210 g180 g
Liquid250 g220 g
Fat22 g38 g
Sugarnone14 g
Eggnone31 g
Salt9 g9 g
Yeast4.5 g6 g

Each line is the group's median for that ingredient, scaled to 450 g of flour.

Closest to the middle of the group

BWith fat, with egg

42 recipes · 42% of all 100 · median oven 350°F (175°C), 27 min

Where it differs from all recipes

  • Fatmedian 17% vs 8.5% for all

    average rank: 75th percentile of all recipes · none in 0% (all recipes 22%)

  • Eggmedian 14% vs 6.8% for all

    average rank: 76th percentile of all recipes · none in 0% (all recipes 47%)

  • Sugarmedian 10% vs 3.1% for all

    average rank: 74th percentile of all recipes · none in 2% (all recipes 31%)

Its median recipe, at 450 g flour

Median recipe of group B in grams, against the median of all recipes
IngredientGroup BAll
Potato170 g180 g
Liquid195 g220 g
Fat75 g38 g
Sugar45 g14 g
Egg60 g31 g
Salt8 g9 g
Yeast7 g6 g

Each line is the group's median for that ingredient, scaled to 450 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 10 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 0.25 · 3 groups 0.25 · 4 groups 0.20. 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 100, 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.