My cookbook says that a salad sauce should be made of 1/3 lemon juice and
2/3 oil. I put 30 ml of oil but my hand slipped when adding the lemon juice
and the total volume is now 70.
How much oil must I now add to have the correct proportions?
as u put 30ml oil and u have 70 so 70-30 is 40 which is 40ml lemon juice. as 1 part is lemon and 2 parts oil out 2x40 so 80ml but as u already have 30 in there only put 50 :)