Brewing Calculator Instructions

The brewing calculator instructions for the Powers Home Brewer’s Recipe Calculator have been written to help eliminate any confusion concerning different parameters required for its proper usage. The Powers Home Brewer’s Calculator has been designed as an easy way to enter all the elements from a recipe. The information calculated from the ingredients and system specifics you enter can be printed on 2 pages of paper that can be taken to the brewery for your current brewing session. It will let you know what quantities of water you will need, what your final gravity might be based upon your yeast selection, and how bitter your recipe should be. The goal of this worksheet is to combine all of the separate calculators available on this site into a single sheet that covers most of the information needed for an average brew session for an average brewer. I intend for this calculator to be free for everyone to use and hope it will serve the needs of all in the brewing community who are looking for an alternative to the various software packages available. It may not possess all the features of the purchasable products out there, but it certainly has everything most brewers would want or need.

To begin using the calculator, you must first enter some information regarding your brewing setup. This information will be stored in a cookie when you leave the calculator page and will be loaded when you return. As long as you do not erase your cookies, your system information will be stored for future use. As an alternative to the cookies, one could create a simple blank recipe template that just contained your name and system specifics that is saved to your hard drive to recall later for recipe formulation. How to do this will be discussed later. The following elements will be essential in correctly calculating your brewing information:

  • Brewer, Date Brewed, and Recipe Name are all self explanatory and do not affect any of the calculations.
  • BJCP Beer Style doesn’t affect the calculations of the recipe. It does, however, populate the Style OG Range, Style SRM Color Range, Style FG Range, and Style IBU Range boxes of the page. This allows you to have a quick reference for style specific data while you are creating a recipe.
  • Batch Size — This is simply the final volume of beer (not including fermentation tank loss) you wish to produce based upon the recipe you are following or creating.
  • Boil Time — This is dependant upon your particular recipe. The boil time is typically between 60 and 90 minutes. The longer your boil, the more liquid you will need in order to achieve your final beer volume.
  • Evaporation From Boil — This amount can vary depending upon your system and how vigorous a boil you are able to achieve. It usually ranges from 9 to 15 percent. My system usually experiences an evaporation rate of about 9%. This is an important figure that may require repeated experimentation in order to determine.
  • Shrinkage Due to Cooling — This value is usually about 4% and is the reduction in volume of your beer from the cooling process that occurs prior to yeast pitching.
  • Brew House Efficiency — This number is a percentage that indicates how efficiently your system is extracting sugars from the grain you are using. If you are unsure, use the default value. A Brew House’s efficiency usually ranges between 60-90 percent. There are many factors that affect this value, one of which includes the size of the crush used for the grains. After you have brewed a recipe, you can enter your ingredients into this calculator and keep adjusting your Brew House Efficiency until your actual and predicted original gravities are equal. You can then use this figure in the future as your Brew House Efficiency. It is important to note that this figure is not to be confused with the Mash System Efficiency which is determined pre-boil and is based on the pre-boil liquid volume. The Mash System Efficiency is usually a slightly higher percentage because it does not take into account the losses in the system. I have chosen to use the Brew House Efficiency for this calculator because I am more concerned with obtaining an accurate pre-fermentation gravity than a pre-boil gravity.
  • Scale Current Recipe — This number is used after you have entered a complete recipe and desire to change the size of the batch by a certain percentage. It always starts from 100% and immediately switches back to 100% after the recipe has been resized. For example, if you wish to double the current recipe size, enter 200% into the box. If you wish to half the recipe size, enter 50%.
  • Weight of Mash tun — The weight of the mash tun is required to determine the heat absorption of the mash tun during mash-in. If you preheat your mash tun, this value doesn’t matter.
  • Thermal Mass of Mash tun — This value may require some experimentation to obtain. It is used to determine the amount of heat absorbed by the mash tun during mash-in. A value of .3 is suitable for a Rubbermaid Cooler based mash tun. If you preheat your mash tun with hot water before the mash, use a value of 0 for this particular variable.
  • Boil Kettle Dead Space — This number refers to the amount of liquid and trub that is left in the bottom of your brew kettle at the end of your boil.
  • Mash Tun Dead Space — This is the amount of liquid lost to the bottom of the mash tun due to the height of the drainage spigot.
  • Lauter Tun Dead Space — This is the amount of liquid lost to the bottom of the lauter tun due to the height of the drainage spigot. Since I pump my sparge water through the heat exchange coil on the way to the mash tun, I include the volume of liquid lost to the coil in this quantity as well.
  • Fermentation Tank Loss — This figure refers to the quantity of liquid lost in the bottom of the fermentation tank due to the settling of yeast, yeast dumping, or all around beer loss.

Next, it will be necessary to enter the Fermentable Ingredients necessary for the recipe you are brewing. When this is done, the calculator will tell you the Total Grain Bill in pounds as well as a predicted Original Specific Gravity based upon your Brew House Efficiency. The calculator will also tell you the Total Non-Mashed Ingredient Bill which includes such things as honey and malt extracts. You will also get to see the Malt Color Units, SRM, and approximate Beer Color in graphical form.

There is one option in this section that deserves a small amount of discussion and it is the Grain Liquid Absorption Factor. This can vary anywhere between .1 and .2 gallons of water per pound. Different grain crushes can cause different absorption rates. I have chosen to have it default to .2 gallons per pound but this can be changed and the factor will be added to your future recipe strings. If you have recipes you saved prior to this change, they will default to the .2 gallons per pound value.

The next step is to choose your Yeast Strain from the pull down menu. Once this is done, the yeast’s Attenuation Percentage factor is pulled from the list and used to calculate the approximate Final Gravity of your brew. This number is based upon ideal yeast conditions and your results may vary slightly. However, it is nice to know about where your brew will finish when the fermentation is complete. The calculator will also tell you what the Alcohol Content, Calories, and Carbohydrates are for you particular recipe.

The next section of the calculator is dedicated to the hops selections for your recipe. Enter the following information:

  • Select the hops you are using from the pull down menus on the left. Once selected, an average alpha acid value for that hops variety will be displayed in the Alpha Acid Percentage box for that ingredient.
  • Enter the quantity, in ounces, you will be using for that particular hops addition.
  • Select the Minutes Boiled for that particular hops addition.
  • Next select the form of hops you are using from the pull down menu. This would be either Pellets or Whole Hop Flowers.

The calculator will then return the Percent Utilization and the Bitterness Units for that particular hop addition.

At this point, you can change the Alpha Acid % for your particular variety if it differs from the values I have put in the database. This information will be saved with the rest of the recipe if you choose to use that feature of the calculator.

When you are done, the calculator will return the recipe’s Total IBUs (International Bitterness Units) in the box in the lower right corner. This number is a reflection of all of the hops addition’s contributions to bitterness based upon the gravity of the beer and the timing of each hop addition (each of which affect hop bitterness utilization). This number is also determined based upon your choice of Bitterness Formula. The formula choice is based somewhat upon personal preference. I prefer the Ray Daniels method of calculation where some people prefer the Tinseth method for full boil bitterness calculations. Feel free to use whatever method you prefer based upon your research.

The calculator will also return the BU:GU ratio for your current recipe. It reflects the ratio of bitterness to the gravity of the beer. This ratio was popularized by Ray Daniels in his book Designing Great Beers and is an excellent tool to use in order to maintain the same perceived bitterness level in a recipe despite its gravity.

Once the above steps are completed, you will know if your recipe’s hops additions allow it to fall within correct style guidelines for the type of beer you are producing. This will also allow you to compare bitterness levels with other beer styles and other recipes. If you like very “hoppy” beers, this value will be high. The reverse is true for beers that don’t have a strong “hoppy” character and are sweeter.

You can use this value to help you during recipe formulation as well. If you produce a particular beer recipe and it turns out to be incorrectly balanced, you can use this calculator to adjust bitterness values to produce the end result you are looking for. Also, if you are forced to substitute a hops variety in a recipe, you can see how it will affect the recipe’s final bitterness values and correct the quantities to obtain the same final bitterness level.

The final section of The Brewer’s Recipe Calculator consists of mashing parameters. This section requires that you enter:

  • Grain Temperature — Measure the temperature of your grains before you begin brewing. This helps to determine the proper strike water temperature. When the strike water and grain are mixed together, the end result should be very close to your recipe’s required initial mash temperature.
  • Mash Temperature — Since I normally do a single infusion mash, this value is usually the saccharification rest temperature. A higher temperature usually results in a sweeter, less fermentable wort while a lower temperature will result in a drier beer with a higher alcohol content. Much time can be spent determining the proper mashing temperatures for grain. For my mashes, I prefer to use an initial mash temperature between 153 to 157 degrees. Since my system is a recirculating mash system, I do not have to worry about calculating additional mash step infusion temperatures if I choose to use an initial protein rest of 122 degrees. I just set a new temperature on my mash controller and let the system do the work.
  • Mash Thickness — This is the number of quarts of water per pound of grain that is going to be used for the mash. Generally speaking, a thinner mash will lead to a drier beer with a slightly higher alcohol content. A thicker mash usually results in a sweeter beer that has a lower alcohol level. I prefer to use a value of 1.2 quarts of water per pound of grain.

Once the above information has been entered, the calculator will determine the proper water quantities needed for your specific recipe as well as the proper water temperature needed to attain your desired mash temperature. It will also note the proper pre-boil volume of liquid you need in order to achieve your desired final beer quantity.

When you print the form, you will notice there are a couple blank sections where you can record your measured brew session data. These include Actual OG, Actual FG, and Actual Mash Temperature. When you return to the computer, you can enter this data into the appropriate form locations and the program will calculate your Alcohol Percentages, Calories, and Carbohydrates along with the Actual Attenuation achieved by your yeast.

The final section of this text deals with a very important aspect of the calculator that others tools of this type on the web don’t possess — The ability to save and load your recipes. Due to the lack of data saving features within the Javascript programming environment and Comcast’s lack of support for CGI, PHP, and other programming languages that allow such features, I have devised a simple way for you to save and load the recipes you have created in my Brewer’s Recipe Calculator.

Simply follow the steps below:

To SAVE your recipe:

  1. Click the Save Recipe button at the bottom or top of the calculator’s screen.
  2. Click anywhere in the small text box that appears in the center of the saving form. These instructions appear on that form as well.
  3. Type CTRL-A to select all of the recipe string.
  4. Type CTRL-C to copy the text.
  5. Open your favorite text editor. I use Microsoft Window’s Notepad program, Mac users could use Appletext. You can use any text editing program on your computer just don’t modify anything in the string.
  6. Paste the recipe string into the editor and save it to your hard-drive under any name you want.
  7. Your recipe is saved.

To LOAD a recipe:

  1. Open the file you saved that contains the recipe string.
  2. Copy the string.
  3. Click the Load Recipe button on the Brewer’s Recipe Calculator page.
  4. Paste the recipe string into the Pop-Up box that appears.
  5. Click the OK button and your recipe information will be transferred to the appropriate calculator cells.
  6. A pop-up notification will let you know when the loading procedure has completed.
  7. Click the OK button and the new recipe will be on the screen and ready to be printed or modified.
Open The Brewer’s Recipe Calculator