There are two ways to substitute ingredients in Breww, depending on how often the substitution may occur and the situation you find yourself in. One method gives you the ability to set alternative ingredient stock items against a stock item, meaning when you start a batch where you do not have sufficient stock of a stock item, you can quickly select a button to substitute this for an alternative. The other method will mean you can substitute the ingredient 'on the fly' with a few additional steps on a brew day.

If you have an ingredient stock item that may occasionally be substituted by another ingredient depending on stock and availability, then you can create a Recipe substitution for this stock item. You can do this by heading to Stock items, selecting to view the stock item and then selecting the '+' symbol next to Recipe substitutions.

You can then choose a different stock item for use when this ingredient is not in stock. You will also be able to set a Quantity multiplication factor and choose whether you would like to Create the inverse substitution too. You will be able to repeat this process and set multiple substitutions, meaning you have multiple options to choose from on a brew day.

The next time you start a batch with insufficient stock of an ingredient, you will need to uncheck the Prevent me starting this batch if there are not enough ingredients in stock checkbox. You will then be able to select the blue substitute button to quickly choose a substitute. This can be done from either the brew sheet, where you will also be able to mark the action as 'complete', or from the Ingredients yet to be added section on the ingredients tab (this won't complete the brew sheet action, but it will add the stock, and the brew sheet action will need to be marked separately). When selecting the Add substitution button, you will be able to select from the batches of your chosen substitutes.

As the brew sheet represents the recipe, the original ingredient from the recipe will always show on the brew sheet, and the new ingredient will never appear there; however, the new ingredient will show as the stock that has been added next to the recipe addition action.

If, for any reason, you unexpectedly need to substitute an ingredient on a batch, this cannot be be done in the brew sheet. Instead, this is managed in your batch's Ingredients tab.

If you do not have sufficient stock of the ingredient and don't intend on substituting it, you may wish to simply mark the ingredient addition as complete in the brew sheet without any batch or quantity assigned, showing that this step has been completed but leaving it “Marked as complete without using any stock”.

To instead add a new ingredient to substitute this, you can simply use the Add ingredient button in the ingredients tab, choose your ingredient and batch, stage added, quantity and recipe stage it was added in. This will mean that 'alternative' ingredient stock will have been assigned to the recipe action of the missing ingredient. The brew sheet will still show the original ingredient addition required, as this uses your recipe; however, the stock used will show the alternative ingredient. You will also be able to add further ingredients to the batch via the Add other button.

You may also remove already assigned ingredients through the ingredients tab by editing an ingredient using the edit button (pencil icon) and setting the quantity to zero. This is particularly useful if you have to remove stock items or ingredients you have assigned if they spilt on the floor, for example, after being assigned.