Batch ingredient scaling
When making a recipe and adding ingredients, you need to enter the full amount to use in total on the recipe (for the recipe's batch size). There is no need to anticipate how many turns will be done later and try to adjust for this as Breww will do this for you. For example, if in the recipe you enter 100kg of an ingredient, and then make a two turn batch, Breww will prompt you for 50kg per turn (assuming the batch volume is the same as the recipe volume).
Breww follows the following steps when determining how to adjust the ingredient quantities added to a batch from a recipe.
- First, Breww checks whether you've chosen to Scale recipe quantities to match batch volume.
- If so, Breww calculates the ratio between the recipe's volume and the batch's planned volume and multiplies all ingredient additions by this ratio to get the quantity to add for each ingredient addition.
This allows Breww to determine the total quantity of an ingredient to use on a batch. For example, if you have a recipe volume of 1,000L, enter a quantity of 300kg for an ingredient for the recipe, and brew a 10,000L batch (with scaling enabled), you will need 3,000kg of the ingredient for the batch. Having multi-turn enabled/disabled has no impact on this calculation.
Using the total quantity determined in Stage 1, this may then be split evenly between each turn in your batch.
- Next, Breww checks if this batch is a multi-turn batch.
- If it is, Breww goes through all of the ingredient additions and checks whether they are added during a stage that Repeats per turn.
- If they are, Breww gets the scaled ingredient quantity calculated earlier and splits it proportionally between each turn.
The diagram below shows this same information in a more visual way:
Let's assume you entered 330kg of a malt on a multi-turn recipe step and gave your recipe a batch size of 500 Litres then:
- If you brew a 500L batch with one turn, that turn will need 330kg of the malt
- If you brew a 500L batch with two turns, each turn will need 160kg of the malt (but still 330kg in total)
- If you brew a 1,000L batch with one turn and enable scaling, that turn will need 660kg of the malt
- If you brew a 1,000L batch with two turns and enable scaling, each turn will need 330kg of the malt (but still 660kg in total)
- If you brew a 1,000L batch with one turn and disable scaling, that turn will need 330kg of the malt
- If you brew a 1,000L batch with two turns and disable scaling, each turn will need 165kg of the malt (but still 330kg in total)
As you can see, the number of turns doesn't impact the total amount of ingredients used, just the amount per turn (to reach the same grand total).
The rules to remember are:
- Scaling being enabled will increase (or decrease) the total amount of stock required for the batch from what was on the recipe.
- If scaling is disabled, then the total amount of stock required will be the quantity entered into the recipe, regardless of how big the batch is.
- Once the total quantity has been determined, this quantity will be divided by the number of turns to get the amount used per turn. The number of turns will never impact the total quantity of the ingredient that will be used for the batch, it will just be split over the turns.
As an example, we'll use the following simple recipe.
Recipe volume: 1,000 L
Stages:
- Mash (Repeats per turn)
- 100 kg x Maris Otter
- Boil (Repeats per turn)
- 20 kg x Citra
- Dry hop
- 15 kg x Amarillo
Let's say we are brewing a 2,000 L batch of the above recipe over two turns and have chosen to scale the recipe up to 2,000 L. First, Breww calculates the scaling ratio: 2,000 L / 1,000 L = 2. Next, Breww scales the total ingredient quantities by this ratio. So, 100 kg of Maris Otter in the Mash would be scaled to 200 kg, 20 kg of Citra in the boil would be scaled to 40 kg, and 15 kg of Amarillo would be scaled to 30 kg.
Next, Breww then looks at each ingredient addition and whether it is part of a stage that Repeats per turn. As we are brewing this recipe over two turns, in our Mash and Boil, the quantity of each ingredient addition will be split proportionally amongst the turns, whilst our Dry hop additions won't be. So Breww will add 100 kg of the total 200 kg of Maris Otter, and 20 kg of the total 40 kg of Citra, to each turn. The Amarillo is used in the Dry hop, which isn't a Repeats per turn stage, so this stage only occurs once and has the entire 30 kg calculated earlier.
This method means that the ratios of the ingredients used remain the same between the stages that Repeats per turn and those that don't. In the example above, the ratio is always 100 kg of Maris Otter used to 15 kg of Amarillo. Whereas if Breww didn't evenly split the total Maris Otter proportionally per turn, then a two-turn batch would have 200 kg of Maris Otter to 15 kg of Amarillo, and a three-turn batch 300 kg to 15 kg etc.
Please see this guide: Multi-turn batchesο»Ώ.
Scaling can be turned on or off for each individual batch (when you start it). When you start the batch, you should see this option:
You can also choose if you'd like this on or off by default in Settings > Production settings.
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