Modify Weight Dialog

Here you can set the weight of an ingredient in different ways.
Type in the weight you want (or use the Volume converter) and then select one of the three ways to update the weight.

Volume

Press the Volume button to bring up the volume to weight conversion tool.
This enables you to convert volume to weight if you for example are adding a recipe where the ingredients are given in volume and not weight.

Limit recipe to ingredient

If you want to limit your recipe to one ingredient and keep the ratio of all ingredients the same you use this button. Say your recipe is for 500g of milk but you only have 300g available. In that case you use this button and all other ingredients will be re-scaled to have the same ratio as before.
Locked ingredients will also be changed when using this method.

Keep recipe total weight

This will update the ingredient with the weight you type in but the total weight of the recipe is no changed. This means all other ingredients are scaled to give the same total weight as before.
Locked ingredients will not be changed when using this method.

OK

Just sets the weight without changing any other ingredient.