The pH of the liquor will have little effect on the pH of the wort and beer. Alkalinity and Calcium are more important in pH control.
Once you have established correct levels of these ions it is advisable to follow the guidelines of typical pH measurements in the brewing process shown below. Hand-held pH meters can be purchased from Murphy & Son Ltd for £58.50.
Please be aware that if you purchase our liquor treatments, you may be entitled to free laboratory testing in the lab and free technical support to ensure you use the correct dosage rates.
Please find the following pH values that are typical measurements and are useful as guidelines when monitoring you pH values.
Raw Liquor pH 6.0-8.0
Treated Liquor pH 6.0-8.0
Mash pH 5.2-5.5
1st Runnings pH 4.8-5.2
Last Runnings pH 5.4-5.6
Wort in Copper pH 5.1-5.4
Wort after boil pH 4.9-5.3
Beer after fermentation pH 3.7-4.2
Alkalinity is mainly caused by calcium carbonate and bicarbonate. The alkalinity of your liquor plays a very important role in pH control. It causes high pH values throughout the brewing process. Hydrogen ions are removed from solution, thus wort pH remains high which results in low extract yield; presence of undesirable protein components; worts and beers prone to infection; increased extraction of silicates, polyphenols and tannins during sparge and harsh “after tastes” in the finished beer.
Reduces the pH during mashing and wort boiling which improves enzyme activity. This is achieved by the calcium ions precipitating phosphates present in the wort as insoluble calcium phosphate which in turn releases the hydrogen ions in the wort which reduces the pH.
3Ca2+ + 2HPO42- → Ca3 (PO4)2 ↓ + 2H+
The optimum pH of the enzyme α-amylase is about 5.7 and that of ß-amylase is about 4.7. Therefore an optimum range in the mash of pH 5.2-5.5 promotes the production of sugars from starch thus making worts more fermentable.
Promotes the precipitation of unwanted proteins in the kettle, hop back or whirlpool. Calcium also has an effect on the precipitation of undesirable wort proteins both during mashing and during the boil
Protein – H + Ca2+ → Protein – Ca↓ + 2H+
The hydrogen ions released further reduce the pH which encourages further precipitation of proteins. The reduction of pH then causes protein breakdown by the enzymes present in malt, this reduces protein levels and increases wort Free Amino Nitrogen levels (FAN).
Improves health and vigour of the yeast. This is a result of FAN compounds being utilised by the yeast during fermentation.
- Improves clarity and stability of the finished product. Reduced protein levels in beers make beer easier to fine and less prone to haze formation, in particular chill haze. The shelf life of the final product is also improved.
- Calcium ions protect α-amylase enzyme from inhibition by heat. Calcium ions also improve enzyme activity.
- Reduces the risk of infection. The drop in pH encouraged by Calcium ions in the mash and copper provides a greater resistance to microbiological infection.
- Reduces extraction of silicates, tannins and polyphenols. These materials contribute to harsh flavours, hazes in the final beer and decreased stability.
- Reduces beerstone and in some cases prevents gushing in beer. Oxalates derived from the malt contribute to the formation of beerstone and are also thought to promote gushing in beer. Calcium reacts with oxalates to form insoluble calcium oxalate which is precipitated out in the mash.
- Reduces colour formation during wort boiling. The extraction of colour forming compounds are reduced during sparging.
- Improves beer fining performance. Calcium ions promote yeast flocculation at the end of fermentation.
For typical levels of ions for different beer styles, Double click following table to see figures…
Optimum pH for Mash Enzymes
• Alpha amylase 5.3 – 5.8
• Beta amylase 4.9 – 5.4
• Proteolytic 4.6 – 5.0
• Peptidase 4.6 – 5.0
• Phytase 5.0 – 5.2
• Mash 5.1 – 5.4
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