For “larger” units of measure (UOM), such as Kilograms, Litres, US Gallons, etc, Breww supports five decimal places on the “price per unit” fields. For “smaller” UOM, such as Grams, ml, oz, etc Breww supports just two decimal places.
It’s been requested to allow more than two decimal places (preferably four) on the “smaller UOM” items too.
If you’d like to see support for this, please give this a vote.