Division 6.1.11 After boiling has continued for 120 seconds (by the stop-watch), start adding standard dextrose solution to the boiling flask (5.1) from the burette, initially in 0·2 ml increments and finally dropwise, until the colour of the methylene blue is just discharged.

Towards the end of this action the time between successive additions of standard dextrose solution shall be 10 to 15 seconds.

These additions shall be completed within 60 seconds, making the total time to boiling no longer than 180 seconds.

A third titration with a slightly larger, appropriately adjusted, initial addition of standard dextrose solution (6.1.9) may be necessary to achieve this.