Adding multiple same ingredients to the fridge

[PrestonTYR]

When I add the same ingredients to the fridge, instead of adding together, the ingredients remain seperate.

For example,
if I do addF i/tomato -1kg,
followed by addF i/tomato -2kg,

When I use the fridge command to view the list of ingredients, the ingredient, tomato does not stack to become tomato 3kg.