Biryani Lab
What moves together in 319 biryani recipes
When a recipe uses more of one ingredient, does it tend to use more or less of another? For every pair of the 8 ingredient ratios (grams per 100 g of uncooked rice), this page ranks all 319 recipes on each and measures how closely the two rankings agree: Spearman's rho, from −1 (the more of one, always the less of the other) through 0 (unrelated) to 1 (always rise together).
28 pairs in all: 5 rise together at rho 0.20 or more, none move in opposite directions at −0.20 or less, and 14 are close to unrelated (between −0.10 and 0.10). This describes recipes as they are published; it does not say what changing one amount would do to a recipe.
Every pair at once
Read a cell by its row and column. Caramel cells rise together, slate cells move in opposite directions, and the deeper the color the stronger the relationship. Pale cells with grey numbers are not distinguishable from no relationship with 319 recipes (p of 0.05 or more).
All 28 pairs as a table
| Pair | Rho | Strength | p |
|---|---|---|---|
| Ghee or oil and spices | 0.30 | weak | under 0.001 |
| Mint and coriander and spices | 0.25 | weak | under 0.001 |
| Onions and ghee or oil | 0.24 | weak | under 0.001 |
| Meat, fish or egg and yogurt | 0.23 | weak | under 0.001 |
| Ghee or oil and mint and coriander | 0.21 | weak | under 0.001 |
| Mint and coriander and salt | 0.20 | very weak | under 0.001 |
| Yogurt and ghee or oil | 0.18 | very weak | 0.001 |
| Ghee or oil and salt | 0.17 | very weak | 0.002 |
| Yogurt and spices | 0.14 | very weak | 0.013 |
| Meat, fish or egg and mint and coriander | −0.14 | very weak | 0.013 |
| Onions and spices | 0.13 | very weak | 0.025 |
| Yogurt and onions | 0.12 | very weak | 0.029 |
| Meat, fish or egg and potatoes | −0.11 | very weak | 0.049 |
| Onions and mint and coriander | 0.11 | very weak | 0.054 |
| Meat, fish or egg and salt | 0.09 | negligible | 0.11 |
| Onions and salt | −0.09 | negligible | 0.12 |
| Ghee or oil and potatoes | 0.08 | negligible | 0.16 |
| Spices and salt | 0.08 | negligible | 0.16 |
| Mint and coriander and potatoes | −0.07 | negligible | 0.21 |
| Meat, fish or egg and spices | 0.04 | negligible | 0.43 |
| Yogurt and mint and coriander | 0.04 | negligible | 0.50 |
| Yogurt and potatoes | 0.03 | negligible | 0.64 |
| Yogurt and salt | 0.03 | negligible | 0.65 |
| Meat, fish or egg and onions | 0.02 | negligible | 0.70 |
| Spices and potatoes | −0.02 | negligible | 0.76 |
| Meat, fish or egg and ghee or oil | 0.01 | negligible | 0.88 |
| Potatoes and salt | 0.00 | negligible | 0.80 |
| Onions and potatoes | 0.00 | negligible | 0.52 |
The three clearest relationships
The strongest pairs that reach rho 0.20 either way with a p-value under 0.01. Each dot is a recipe; the line joins the median of the second ingredient within each fifth of recipes ranked by the first.
Recipes with more ghee or oil tend to use more spices
rho 0.30 across 319 recipes · weak · p under 0.001
The third of recipes with the most ghee or oil use a median of 5.8% spices; the third with the least ghee or oil, 4%.
Recipes with more mint and coriander tend to use more spices
rho 0.25 across 319 recipes · weak · p under 0.001
The third of recipes with the most mint and coriander use a median of 5.7% spices; the 121 with no mint and coriander, 4.1%.
Recipes with more onions tend to use more ghee or oil
rho 0.24 across 319 recipes · weak · p under 0.001
The third of recipes with the most onions use a median of 18% ghee or oil; the third with the fewest onions, 11%.
What moves on its own
- Potatoes. Nearly independent of the rest: its strongest correlation with any other ingredient is −0.11, with meat, fish or egg. A recipe's amount of potatoes says almost nothing about its other amounts.
The pairs closest to unrelated: onions and potatoes (0.00), potatoes and salt (0.00), meat, fish or egg and ghee or oil (0.01) and spices and potatoes (−0.02).
How the numbers are made
Spearman's rho is the ordinary correlation of the two rankings, so it measures whether one amount tends to rise with the other, in a straight line or not, and a single extreme recipe moves it little. A recipe with none of an ingredient ranks lowest on it. An ingredient fewer than 12 recipes use is left out of the matrix.
The p-value is the chance of a rho at least this far from zero if the two amounts were unrelated. With 28 pairs tested, about 1.4 would pass 0.05 by chance alone even if no ingredient were related to another, which is why the relationships explained above must pass 0.01 and reach 0.20.
Every number is divided by the same uncooked rice weight, so a recipe with little uncooked rice for its other ingredients reads high on every one of them at once. That nudges every correlation toward positive: part of a positive rho can be the rice, not the two ingredients. A negative one holds despite it.
A correlation describes the recipes as published. “Recipes with more meat, fish or egg tend to use…” is a statement about what cooks write down together, not a rule that adding one forces the other. Plot any two ingredients to see the recipes behind a number.