Style (Recipe) Design History Calculation Info

Alcohol (% abv)
Alcoholic content (as % alcohol by volume) is calculated from temperature corrected specific gravity (SG) readings. The method used is detailed under method 2 under "Potential Alcohol" here.

Titratable Acidity (TA)
Titratable acidity is calculated as tartaric acid (as is practically the international convention) using an NaOH titration and a pH meter to the endpoint pH 8.2. (This follows the U.S. AOAC (Association of Official Analytical Chemists) method. Sample is typically 10 ml and undiluted.)

pH
pH is given to two decimal places and is calculated (with temperature compensation) with a meter accuracy of +/- 0.01 and a buffer solution accuracy of +/- 0.01, resulting in an overall pH accuracy of +/- 0.014. Where pH is given to one decimal place, meter accuracy is +/- 0.2 (resolution 0.01) and overall pH accuracy is +/- 0.200. (Frequent calibrations are made with pH 4.01 and 7.01 buffers.)

Residual Sugar (r.s.)
Residual sugar is given as a specific gravity reading or back calculated from Brix readings.
Brix values are based on SG values using the formula: Brix = ((SG-1)*220)+1.6

Free SO2 (FSO2)
Free SO2 is calculated using Titrets. Value adjustments may be made. Control solutions are used for calibration.

Tasting
All tastings are conducted using standard ISO tasting glasses. Most tastings are verified by both experienced and inexperienced tasters other than the winemaker. Such tastings are almost always conducted blind.