Shortbread Lab · Decision tree
Find your shortbread
Two questions sort all 433 recipes into 4 groups. Each question is about one of the ingredients recipes disagree on most, and splits the recipes in front of it at their own median, so each answer keeps about half of them. Every group ends with its median recipe in grams and the real recipes nearest it.
The questions
Question 1
More sugar than most, or less?
Sugar at about half the butter. Powdered sugar gives a finer, sandier crumb than granulated.
All 433 recipes: median 40% of the flour weight, 100 g per 250 g of flour; middle half 33% to 51%.
Question 2
More butter than most, or less?
Butter is the point. The Scottish ratio is two parts butter to three of flour; more makes a shorter, more melting biscuit.
All 433 recipes: median 81% of the flour weight, 200 g per 250 g of flour; middle half 69% to 91%.
Asked within each answer to question 1, split at the median of the recipes that gave it.
The key
Read left to right: pick an answer to question 1, then one of the answers beside it for question 2, and so on to a group. Each cell gives the answer, its bound in grams per 100 g of flour, and how many recipes give it.
The 4 groups
Each median recipe is the median of every ingredient over the group's recipes, scaled to 250 g of flour, beside the typical pan of all 433. Bold rows are the ingredients the questions asked about.
Group A · 107 recipes · 24% of all
More sugar and more butter
Sugar 40% or more and butter over 86% of the flour weight.
| At 250 g flour | Group A | All |
|---|---|---|
| Flour | 250 g | 250 g |
| Butter | 225 gabout 1 cup | 200 g |
| Sugar | 130 gabout 2/3 cup | 100 g |
| Starch | none | none |
| Salt | 1.5 g | 1 g |
Bake350°F (175°C) for about 18 minutes, the medians of the 97 recipes here that state a temperature and the 105 that state a time.
Nearest the middle of group A
Closest to the group's median on every ingredient at once.
- Shortbread Cookies · bakingamoment.comsugar 53% · butter 91%
- Shortbread Cookies · twopeasandtheirpod.comsugar 50% · butter 91%
- Lemon And Rosemary Shortbread Cookies Recipe · archanaskitchen.comsugar 53% · butter 91%
- Chocolate Shortbread Cookies · bakeschool.comsugar 46% · butter 92%
- Shortbread Cookies · kingarthurbaking.comsugar 47% · butter 95%
Group B · 112 recipes · 25% of all
More sugar and less butter
Sugar 40% or more and butter 86% or less of the flour weight.
| At 250 g flour | Group B | All |
|---|---|---|
| Flour | 250 g | 250 g |
| Butter | 190 gabout 3/4 cup | 200 g |
| Sugar | 130 gabout 2/3 cup | 100 g |
| Starch | none | none |
| Salt | 1 g | 1 g |
Bake350°F (175°C) for about 18 minutes, the medians of the 100 recipes here that state a temperature and the 108 that state a time.
Nearest the middle of group B
Closest to the group's median on every ingredient at once.
- Irish Shortbread Christmas Tree Cookies · biggerbolderbaking.comsugar 46% · butter 74%
- Apricot Lavender Shortbread · baking-sense.comsugar 49% · butter 80%
- Cranberry Orange Shortbread Cookies · beyondfrosting.comsugar 51% · butter 81%
- Cranberry Shortbread Cookies · beyondfrosting.comsugar 51% · butter 81%
- Shortbread Cookies with Raspberry Preserves · natashaskitchen.comsugar 46% · butter 78%
Group C · 106 recipes · 24% of all
Less sugar and more butter
Sugar under 40% and butter over 79% of the flour weight.
| At 250 g flour | Group C | All |
|---|---|---|
| Flour | 250 g | 250 g |
| Butter | 225 gabout 1 cup | 200 g |
| Sugar | 80 gabout 1/3 cup | 100 g |
| Starch | none | none |
| Salt | 1.5 g | 1 g |
Bake350°F (175°C) for about 15 minutes, the medians of the 98 recipes here that state a temperature and the 98 that state a time.
Nearest the middle of group C
Closest to the group's median on every ingredient at once.
- Toffee Pecan Shortbread Cookies · houseofnasheats.comsugar 32% · butter 91%
- Shortbread Cookies Recipe · crazyforcrust.comsugar 30% · butter 91%
- Gluten Free Shortbread Cookies · thatgirlcookshealthy.comsugar 31% · butter 89%
- Lemon Rosemary Shortbread · twopeasandtheirpod.comsugar 36% · butter 91%
- Twice-Baked Shortbread · smittenkitchen.comsugar 32% · butter 90%
Group D · 108 recipes · 24% of all
Less sugar and less butter
Sugar under 40% and butter 79% or less of the flour weight.
| At 250 g flour | Group D | All |
|---|---|---|
| Flour | 250 g | 250 g |
| Butter | 165 gabout 3/4 cup | 200 g |
| Sugar | 85 gabout 1/2 cup | 100 g |
| Starch | none | none |
| Salt | 0.5 g | 1 g |
Bake350°F (175°C) for about 18 minutes, the medians of the 94 recipes here that state a temperature and the 102 that state a time.
Nearest the middle of group D
Closest to the group's median on every ingredient at once.
- Shortbread met citroen · uitpaulineskeuken.nlsugar 33% · butter 67%
- Tricolore shortbread-koekjes · 24kitchen.nlsugar 33% · butter 67%
- Shortbread · cucchiaio.itsugar 34% · butter 66%
- ceylon earl grey shortbread · deliciousmagazine.nlsugar 33% · butter 67%
- Chocolate chip shortbread · bbcgoodfood.comsugar 33% · butter 67%
How the questions are chosen
Each ingredient is ranked by how much recipes disagree on it: the width of the middle half of recipes (25th to 75th percentile) divided by the median, less 4% for each place it sits down this lab's list of ingredients, so the ones that define the dish win near ties. For shortbread the order is sugar (0.45) and butter (0.27), and the first 2 are asked. Salt is never asked about: recipes differ on it mostly by brand and taste. Starch is left out because most recipes use none.
Every split is at the median of the recipes in front of it, rounded to the percentage shown. Recipes exactly at the median go to whichever side leaves the two halves more even. No answer may keep fewer than 5 recipes; a group that could not be split further says so.
The recipes listed under each group are the 5 nearest its median on every ingredient at once, each scaled by how much recipes vary on it. Every recipe page links to the original for the method.