Finger test:
- If you hold a fingernail-sized food sample (1.5 x 1.5 cm) between your thumb and index finger and press hard enough to turn your fingernail white, the food will be crushed and cannot return to its original shape after you release your fingers.
 
References:
The International Dysphagia Diet Standardization Initiative (IDDSI)
https://iddsi.org/