# 🍺 Top-down Brew: Beer Engine 2024 Use and Documentation

This is documentation of how the various parts of the calculator work. More information is available about the philosophy and an example recipe.

Original Gravity

Enter the target original gravity as specific gravity (example: 1.048) or degrees Plato (example: 12). Values smaller than 1.2 are assumed to be in specific gravity units.

Target volume

Enter the target volume at the end of the boil. The volume units can be liters, gallons, or US barrels. The preferred units of measurement is chosen below.

Measurement Units
Metric US US Barrels

Select the preferred unit of measurement for the inputs and outputs. Metric uses liters, grams, and kilograms. US uses gallons, ounces, and pounds. US Barrels (31 gallons = 1 barrel) is in barrels, pounds, and ounces.

Mash Efficiency

Mash efficiency is the percentage of sugars extracted during sparging. If this is not known, try the following values based on the sparge method: Steeping (50%), No-sparge or brew-in-a-bag (65 to 75%), Batch sparge (80%), or Continuous (fly) sparge (85 to 90%).

Grains

Enter the mashed grains for all-grain or partial mash brewing. Use a separate field for each grain type. The order of data in a field is malt or grain name, fermentable percentage, Lovibond, and yield. The data points must be separated with commas. Yield can be entered as either coarse-grind as-is percentages (example: 80% for two-row malt) or specific gravities (example: 1.037 for two-row malt). Yield values between 1.0 and 1.5 are assumed to be in specific gravity units. The data used can come from the analytical analysis provided by major malt companies or by values suggested in these databases.

- Brew United's grain database
- BYO magazine grain and adjunct resource

Sugars

Enter the sugar or malt extract values with a separate field for each type. The data order in a field is name, fermentable percentage, Lovibond, and yield. Malt extract brewers should enter the malt extract values here. Dry and liquid malt extracts typically have a 1.044 (96%) or 1.035 (76%) yield, respectively. The following BYO link has typical values for a range of sugars.

- BYO magazine sugar resource

Bitterness

Enter the target IBU values. The BJCP style guidelines provide a range of values typical for each beer style. For clone recipes, commercial brewers often provide IBU values on their web site or the label. Bitterness unit to grist unit (BU/GU) ratio is also part of the output.

Hops

Enter the hop data for each hop addition in separate fields. The data order in each field is hop name, IBU percentage, alpha-acid percentage, and boil time in minutes. IBU percentage is the contribution of a hop to total IBUs. For example, using a single bittering hop addition would be 100% of the IBUs. Late hop additions are typically 10 to 20% of total IBUs. The IBU calculations are based upon Tinseth formula, with additions at 1 or less minutes in the boil end adjusted upward to have a 5% utilization. The calculations estimate boiling gravity based a 15% per hour boil-off rate.

- Beer-analytics.com American Pale Ale
- Brew United hop database
- BYO magazine's hop resources

Late Boil Additions

Enter the late boil additions like spices, yeast nutrients, or Irish moss. The name and dosage must be separated by a comma. The dosage format input must use grams per liter. When these late additions are not desired, enter "none" or leave the field blank.

Dry Hops

Enter dry hops with name and dosage (grams/liter), with a comma separation. When dry hopping is not desired, enter "none" or leave the field blank. The following values are suggested dosages for pale ales and IPAs.

- 0.5 to 0.9 g/l: Light
- 1.0 to 2.0 g/l: Moderate
- > 2.0 g/l: High

Yeast
Ale Lager

Select either an ale or lager pitching rate. The ale pitching rate for wort below 17 degrees Plato (1.068 SG) is .5 g/l for dry yeast or .75 million/mL/°P for liquid yeast. Ales at 17 degrees Plato or higher are 1 g/l (dry) or 1.0 million/mL/°P (liquid). The lager pitching rates are double the ale values.

← Click here when the data entry is done.

## Results

*** Waiting for results ***

## Notes

The text in the "results" section can be copied and pasted into your favorite word processor, saved, and printed.

Your can make your own calculating web pages by editing the default value fields with a text editor. Add your own descriptions in the html parts. Be sure to keep the javascript file BeerEngine2024.js and CSS page in the same directory as the web file. More information is provided in another page for making your own calculating web pages.

Feel free contact the author if significant bugs are found.

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