| Independent variables | Symbol | Unit | Minimum | Level | Maximum |
|
|
|
| −1 | 0 | 1 |
| Volume (tiger nut milk) | X1 | l/kg | 2 | 3.5 | 5 |
| Mass of sugar | X2 | G | 50 | 62.5 | 75 |
| Mass of milk | X3 | G | 20 | 70 | 120 |