# Top-down Brew: Change Log

This tracks the web site changes and has some blog posts.

## May 12, 2026: Beer engine update

The beer engine software receive a major update. Most of the changes were to improve the user interface. The files associated with the 2024 version were also migrated over to this new platform.

## August 3, 2025: TZ Pils, improved conversion tools

The TZ Pils reciped was added to the beer engine concise page. The hop and malt tools for converting recipes to the beer engine concise code were improved. The previous version just produced percentages. The new version has percentages plusthe malt, sugar, or hop codes needed for a beer engine concise input. The page describing beer engine concise now has more description about the codes.

## March 16, 2025: Change log switch

This change log is new. It's mostly to document changes happening at the topdownbrew.com web site. Having a historical record is important. Changes will not be posted at the blogger.com web site any longer.

## March 13, 2025: Old Peculier clone added

An Old Peculier clone was added. The BE Concise javascript rounding bug for errors was fixed by rounding to the hundreths place. The grain weight percentage calculator was improved by adding two more lines that were needed for the complex Old Peculier grain bill.

## February 20, 2025: Priming technical improvement and ordinary bitter style

During development of the carbonation calculators I noticed that there was some variation in the sources about a key constant: the mass of one liter of CO2 at standard temperature and pressure. The calculators were based upon the value of 1.969 from Kaminski (2019). Reddit user /u/chino_brews noted that this value was slightly off and suggested the following correction.

"One mole of CO2 has a mass of 44.01 g. AT STP, one liter [I think he meant mole] of gas occupies 22.4 L of volume. 44.01 / 22.4 = 1.96473214286."

The priming calculators have been updated with this new, more accurate constant. This small change probably doesn't make much difference at the homebrew level, but hey, why not? Increased precision is always valuable.

In other news, a FlexStyle calculator for an ordinary bitter has been added. My interest in British styles was triggered by my homebrew store being sold out of Rahr two-row, so I went with Simpson pale ale malt instead. Brewing with British malt is new to me. I'm looking forward to it. I'm also currently interested in exploring session beers as part of a more healthy lifestyle.

Update March, 2025: This ordinary bitter page was expanded to include ordinary, best, and strong bitter styles.

## January 17, 2025: Updated: Mash efficiency - advanced

The advanced mash efficiency page has received some major and minor updates.

The first major update is that the tool follows John Palmer's example more closely (2001, p. 148 - 152). The older version calculated gravity points for an entire batch. For example, 5 gallons at 1.037 would be 185 gravity points (theoretical maximum). The current version expresses this per gallon or per liter, which is how Palmer's calculations work. The math is really equivalent, but it might be easier to understand when expressed per volume unit.

A second major update is the metric calculations use L degrees per kilogram. The previous version just converted metric units to imperial (US) units, then did the calculations with the imperial units. This crude approach worked for calculating efficiency, but it was perhaps disappointing to people who use metric units.

There were a few other minor tweaks. Malt extracts were moved from the base malts to the sugar options. The description of the calculations was edited to improve clarity and explain metric calculations.

Palmer, J. (2001). How to Brew. Second edition. Defenestrative Publishing Co.

## January 11, 2025: Updated: Water estimation tool for continuous sparging

The water estimation tool received a few tiny adjustments in regard to how water use is estimated for continuous sparges. These depend upon maintaining a medium-thickness mash throughout the sparge process.

A coding comment incorrectly stated that 1.4 l / kg of water were used to estimate water absorption plus excess water for continuous sparging. The calculator was actually using 2.0 l/kg as stated in the documentation. The update also bumped this value up from 2.0 l/kg to 2.5 l/kg to be more conservative.

The description of how this calculator works was edited for greater clarity.

## October 1, 2024: New additions: Dubbel, witbier, Hoegaarden, and clone estimation tool

Here are a few new additions.

Flexstyle: Two new style based calculators were added for Belgian dubbel and witbier.

Flex concise: A new clone recipe calculator was added for Hoegaarden.

A new tool is helpful for estimating the starting point of clone beer recipes. Known values like original gravity or alcohol by volume can be used to estimate the weight of malt extract or malt that will be needed. There are three different methods possible depending upon what is known about the commercial beer. The goal is to save a bit of guesswork. The inspiration for these calculators came from documentation in Clonebrews (Szamatulski & Szamatulski, 1998).

## July 1, 2024: Mash efficiency advanced - unit choice

The advanced mash efficiency calculator has been updated. The previous version used imperial (US) units: gallons and pounds. The new version will do either US or Metric units.

Mash efficiency advanced

## May 17, 2024: Calories and carbohydrates in a beer serving

This new calculator will estimate the calories and carbohydrates (grams) in a beer serving. It's sad, but true: Beer has a lot of calories.

Something that surprised me is that the highest amount of carbohydrates come from the ethanol. The sugars that give beer some body are only the second highest source of calories. Always learning!

There are two calculators on this page. The first method will estimate both calories from alcohol and other carbohydrates if the original gravity and final gravity are known. The second method is for the calories from alcohol if only the ABV (alcohol by volume percentage) and serving size are known.

Calories and Carbohydrates calculator

## May 13, 2024: New tools: Dry priming, British brown ale calculators

The /r/homebrewing group on Reddit has recently shown interest in dry priming. This is natural carbonation achieved through adding a small amount of sugar to each bottle before filling with beer and capping. This was commonly done in prohibition-era homebrew. One modern way to do this is through commercial solutions like Cooper's carbonation drops: Add one hard candy-like tablet to each bottle. A related solution some redditors have described using syringes to measure out precise amounts of sugar syrups into each bottle.

Dry priming has some advantages over the commonly done method of mixing the beer with all of the sugar for a batch in a bottling bucket. Oxygen exposure - the primary cause of staling - should be lower due to less handling. There is less equipment to clean because there is no need for a bottling bucket.

I noticed there was some inconsistency in the discussion about how much sugar is the right amount. This new calculator addresses the issue by using temperature and desired carbonation level to determine the amount of sugar needed for each bottle. The standard output is for 12 oz (355 ml) and 16 oz (473 ml) bottles. The custom field will provide an amount for less common bottle sizes.

Carbonation with sugar - dry priming calculator

The tool for estimating how many bottles are needed for each batch was updated to provide an estimate based on 16 oz (473 ml) bottles.

Several new Beer Engine 2024 recipe calculators have also been added.

- Flexstyle: British Brown Ale
- Concise: Sierra Nevada Resilience IPA clone
- Concise: Genesee Cream Ale clone
- Concise: Newcastle brown ale clone

## May 12, 2024: Beer Engine 2024 - Concise: A new format for sharing recipes

The Beer Engine 2024 software was created to power the FlexStyle calculators that create a recipe based on beer styles. Later, it occurred to me that sometimes brewers just want to share a recipe with others without exploring the intricacies of a beer style. Something more compact than FlexStyle would be very practical for sharing purposes.

Communicating brewing recipes is awkward because brewers have differences in equipment and processes. Mash efficiency is a key issue. Commercial breweries that continuous (fly) sparge might have 90% efficiency whereas a brew-in-a-bag homebrewer might get 70% efficiency. Simply reporting the weights in a grain bill can is problematic because of these differences. The 70% brewer will need more grain for the same volume than the 90% brewer. There needs to be a way to easily bridge this gap.

The Beer Engine 2024 - Concise software has the critical recipe variables in a single field. Simple codes are used like m: for malt and h: for hops. The values associated with a variable are separated by commas (i.e., comma separated values) and can be easily edited by the user if desired. Here are two examples.

- m: Malt name, fermentable percentage, Lovibond, and yield (SG or percent)
- h: Hop name, IBU %, alpha acid %, and boil minutes

Here's an example for a basic American pale ale.

    og: 1.053
    m: American two-row, 91, 2, 80
    m: Crystal 40L, 6, 40, 75
    m: Wheat malt, 3, 2, 80
    ibu: 38
    h: Cascade, 70, 5.75, 90
    h: Cascade, 15, 5.75, 60
    h: Cascade, 15, 5.75, 30
    dry: Cascade, 2
    y: ale

In brief, the grain bill is 91% American two-row malt, 6% crystal 40L, and 3% wheat malt. The hops are all Cascade at 5.75% alpha acids, with additions at 60, 15, and 0 minutes.

The og: line is original gravity, which can be either specific gravity or degrees Plato. The ibu: variable is the target bitterness. The dry: is for dry hops (grams/liter). Finally, y: is for yeast type to calculate the pitching rate. The rest of the inputs are user-specific variables, such as the desired volume and mash efficiency. Altogether, this method provides a very compact method for specifying the recipe parameters.

The field can be edited. For example, if a brewer's hops are 5% alpha acids instead of 5.75%, the values can be changed to fit the brewer's hops. A second example is that the type of hops could be switched, like Cascade to Centennial, by changing the hop name and the associated alpha acids.

This recipe format is very portable. To illustrate, a print magazine could publish the code shown above on paper. The brewer could type it into the Beer Engine 2024 - concise page and press the button to get the weights needed for their specific brewing situation. No software purchase would be needed because this is available for free on the web and has open-source licensing.

Here are a few concise recipe calculators to explore.

- The American pale ale example shown above, with additional explanations
- Guinness draft clone with instructions for malt extract variations
- Sierra Nevada Resilience IPA clone with instructions for malt extract versions

## April 20, 2024: Interview with Rob (from the Internet) Talks About Beer

YouTuber Rob (from the internet) had me on his show Talks About Beer. We shared an Irish Red, talked about brewing, and had a good time. I thank Rob for having me on the show. It was a great experience. Check it out if you have some time.

- Rob (from the internet) Talks About Beer, Season 4, Episode 1 with Gary Fisk. The discussion is about Irish Red style and homebrewing. The Beer Engine 2024 calculator at topdownbrew.com is described.
- Try the Beer Engine 2024 recipe calculator for the Good Red Earth recipe featured on the video.
- Rob has numerous other interviews about a wide range of craft beer topics on his channel.

I heartily thank Rob for having me on the show. It was a great experience.

## October 14, 2023: FlexStyle recipe calculator: Sierra Nevada pale ale

My recent project is web-based homebrewing recipe calculators. These are single web pages dedicated to brewing a specific recipe, like a clone beer, or make your own recipe within a beer style. These style-focused calculators are called FlexStyle, a combination of flexible and style.

The vision is that these calculators meet a need that is in-between the complete inflexibility of printed recipes and the unlimited flexibility of brewing software like BeerSmith. The user has some control over inputs, but it is constrained to provide some guidance. These can work like templates to guide newer brewers into style-appropriate recipes.

All of the FlexStyle recipes are located on the FlexStyle home page.

The most recent additions are two clone recipes for American pale ale (BJCP 18B). The first clone is for Sierra Nevada's pale ale, an important pioneer of today's craft beer market. The second clone is based on a homebrew recipe that is reportedly from Ken Grossman's homebrewing notes. This was the predecessor of Sierra Nevada's current pale ale. It's a bit bigger than the commercial offering. It is also interesting from a historical perspective.

UPDATE April, 2024: These links are now available at the new Beer Engine 2024 index.

## September 8, 2023: Parti-gyle blending calculations

Gordon Strong recently wrote an article in Brew Your Own magazine about "alternative" mashing techniques. Parti-gyle brewing was an old British method for brewing two or more beers of different strengths from a single mash. A strong first running (or gyle) was combined with a weaker second running to produce an intermediate strength beer. The article describes the basic concept for calculating the blended specific gravity, but does not go into much detail.

The parti-gyle blending calculator provides two useful calculations for parti-gyle brewers. The first option can estimate the gravity of a wort created by blending two worts of different strengths. This is similar to the calculations described in Strong's article. The second option will estimate the volume of the second running needed to achieve a target specific gravity in the blended wort. The calculations from both options are explained.

https://topdownbrew.com/PartigyleBlending.html

Strong, G. (2023, September). Alternative mashing techniques: Traditions of England, Germany, and the Czech Republic. BYO, p. 30 - 39.

Go back to the calculator list.

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