A parti-gyle brew produces worts of diminishing strength, the first being the strongest and the last, the weakest, known as small beer. Each wort could be combined with others to make beers of defined strength. When all worts were combined the product was known as “entire”. This calculator provides for combinations of the first three complete worts and the result of evaporation in boiling and the coolers.

This calculator is primarily for assessing the strength of historic brews, but it can be used for your own brews for simulation or if you want to try out a partigyle brew.

Fill in the boxes with blue labels.

Malt kg

Weight of malt in kilograms.

Liquor litres

English brewers refer to liquor, not water. Total amount of liquor to make a given amount of wort takes into account the absorption of the grains and evaporation in boil and coolers. Calculate using the Initial Liquor Calculator. When calculating multiple separate worts the initial liquor is usually for the first wort and extra liquor (and sometimes malt) added to each wort.

Extract LDK as is

Terms seen on malt analyses. Hot water extract defined as litre degrees per kilogram. As is does not include moisture. If a number of malts are used LDK can be determined by weighted averages. When simulating historic beers use the value given in the book (to come later).

Extract Potential %

If LDK is not available potential extract percent can be used here. Any figure in LDK will be ignored.

Malt/Liquor Ratio

Thickness of the mash in litres of wort to kilograms of malt

Conversion Efficiency

Extent of the conversion of starch to sugars. For simulating historic beers use 100% and LDK for the year given in the book. When making your own beers adjust according to the efficiency of your system.

Absorption Rate

Absorption of liquor by malt in litres of liquor per kilogram of malt. The first mash will absorb liquor at this rate. This figure is preset at 1 but may be altered. Historically, brewers reported a range of values, however 1 ltr/kg is close to the average. For your own beers you may find the value to be lower. Some use a value of 0.8 ltr/kg. My own experience is 0.95 ltr/kg.

Collected Wort

Enter the volume of wort collected from the mash.

% Evaporation in Boil, Coolers etc.

Evaporation in the boil reduces volume and increases the gravity. Historically, brewers also had evaporation from the coolers. Enter the total evaporation percent to find the new volume and specific gravity. The combined evaporation can be calculated using the Initial Liquor Calculator.