If you wish to formulate a recipe the following are some guidelines to help you. Detailed calculations are available on our on-line or tutored courses.
Recipe Formulation – Initial Decisions
- Target ABV (alcohol by volume)
- Style of beer
- Volume to make
- Yeast strain to use
Recipe Formulation – Calculation of OG
- Gravity needed for the required ABV using the F Factor table
- Determine the Original Gravity (OG) for a yeast strain and/or mashing in temperature.
- The difference between 2 b. and 2 a. will give you an idea of the Final Gravity (FG) of the beer.
- Note that altering the mash temperature can increase or decrease the FG
Recipe Formulation – Calculation of LDK needed
When you have the OG you can then calculate the
- LDK (litre degrees per kilogram) at 100% efficiency
- Using the mash efficiency, you can then calculate the total LDK needed.
Recipe Formulation – Calculation of the weights needed of each malt
Once you know the total LDK needed you can
- Calculate the weights of each ingredient using the extract potential of each malt/adjunct/sugar
- The extract potential can be found on the malt data sheets
Recipe Formulation – Calculation of the liquor needed to hydrate the mash and the sparge liquor volume
Add up all the weights of the dry ingredients to calculate the
- Mash liquor required to hydrate the dry ingredients
- The sparge liquor required to extract the sugars
Recipe Formulation – Calculation of water (liquor) treatment
- The next stage is to calculate the water treatment needed for a beer style
- Decide if you need to increase or decrease the alkalinity
- From this calculate the amount of acid or bicarbonate to add to the liquor tank
- Note the liquor tank volume is different from the brew volume
- Next calculate the amount of Calcium Sulphate you need to add for the beer style you are making
- Then calculate the amount of Calcium Chloride for the beer style
- The next stage is to determine if you have enough calcium
- Calculate the Calcium required for the beer style
- Calculate calcium from the liquor sullied and from the Calcium Sulphate and Calcium Chloride
- If there is a surplus Calcium that is acceptable
- If there is a shortage of Calcium you may have to review the water treatment you are using for alkalinity reduction.
Recipe Formulation – Colour calculations
Then calculate the colour of the beer
- To do this you will need the weight from each malt/adjunct/sugar
- The colour potential from each malt/adjunct/sugar.
- The colour potential can be found on their product data sheets.
Recipe Formulation – Hop calculations
Final part of the recipe formulation is to look at the hops you need and determine the bitterness
- First Decide what EBU you are aiming for
- Decide what the final bitterness you require in the beer
- Decide what hops you are going to use for both first addition and late additions
- Obtain the % alpha acid for each hop
- Decide the weight of each hop you are going to use as a late hop and at what stage of the boil you are going to add these.
- Calculate the EBU produced from each late hop addition and add these together
- From f. you can then calculate the EBU needed from the first hop addition by subtracting (a.-f.)
- Once you know the EBU needed from g. calculate the weight of each hop to use as the first hop.
Written by Brian Yorston, Course Manager at Brewlab.Return to Brewlab blog