Data from the last 4 brews is given below.
Alkalinity reduced using CRS for all brews and measured using a Salifert kit. Alkalinity given as ppm CaCO3. pH measured at 15-20 minutes into the mash using a Voltcraft PH-100ATC. Wort temperature reduced to 20°C for measurement. pH meter calibrated before use with pH 7 and pH 4 buffer solutions.
- Liquor alkalinity 45, pale malt 74.8%, Vienna malt 18.7%, Crystal malt 4.7%, Chocolate malt 1.9%. pH 5.4
- Liquor alkalinity 16, pale malt 83.1%, Vienna malt 12.2%, Biscuit malt 4.6%. pH 5.4
- Liquor alkalinity 30, Pale malt 90.6%, Crystal malt 5%, Chocolate malt 1.3%, Flaked oats 3%. pH 5.2
- Liquor alkalinity 18, Pale malt 89.6%, pale Crystal malt 6.8%, flaked oats 3.6%. pH 5.6
Any thoughts on what's going on would be appreciated, together with ideas on how to get the pH routinely dpwn to the bottom of the acceptable range.
The beers all taste ok, by the way!!