Ontario District MBAC
Technical Meeting Labatt
London, Ontario
September 23, 2004
REPORT

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Guillaume Lermusieau of Labatt Breweries discussed the 'pH Paradox in the Malting & Brewing Process'. This talk was based on his part of the De Clerck Chair XI that took place in Leuven, Belgium earlier this year.

The main topics of his talk included:

1. The fact that levels of Ca2+ in sparge and mashing water should be different because higher sparge Ca2+ gives lower pH during run-off. It is better to adjust sparge water than to acidify wort in the kettle because flavour instability precursors will be leached out in the lauter tun with higher pHs.
2. The impact of boiling on pH, some of which are:
1. pH drop is higher in lower gravity wort
2. Hopped wort inhibits gram+ bacteria - antiseptic potency increases as pH decreases
3. Bittering increases as pH increases - pH increase of .2 or .3 doubles humulone extraction

   eg. at pH 5.0 humulone = 40 mg/L @ 25 ºC
   at pH 5.9 humulone = 480 mg/L @ 25 ºC

4. higher pH = higher coagulation - 4.8 to 5.2 pH = best clarity and precipitation in the WP
• as pH increases (5-6) have increased cold break, and use less kettle finings
• good correlation between wort break clarity and cold break proteins
5. SMM to DMS speed of reaction increases with temp and pH
• stable in range 4 to 5
• as pH increases, half-life of SMM decreases:
• at pH 4, half-life is 400 min. at 82 ºC
• at pH 8, half-life is 10 min. at 99 ºC - temperature is the more important factor
6. Foam stability can be varied with pH at boil but at the end of fermentation the foam stability is always the same no matter what the start point is.
7. Colour - if pH up by 1 unit, colour goes up by 2 - mainly oxidation of tannins
8. Flavour stability - higher the pH during the boil, the lower the flavour stability

If one corrects the pH at end of boil there are better flocs in whirlpool and a faster reduction of diacetyl with the lower pH.

A pH balance is needed - 5.4 during boil, 5.0 at end of boil would be ideal.

Peter George and Doug O'Gilvie of Draught Equipment Services gave a talk entitled 'Draught Beer in the Pub' on the evolution of, and services offered by their division.

The primary focus of Draught services is ales and installation of draught lines, towers, and coolers; line cleaning service; TBS keg float maintenance; and technical advice and support to licensees.

Since 1999, 45 distribution points have been reduced to 5 major distribution centres and 9 cross-docks serving the 17,000 licensees in Ontario, 40% of whom sell draught totalling 1.8 million hLs. Home consumers buy 38,000 hLs a year of draught.

The group helps to develop and sells and installs equipment. They also retail parts and fittings. A British group has had them do some draught installations in cities in Great Britain. An important advance in dispense technology has been fob or foam detectors that prevent lines from being "blown" by emptied kegs. The licensee can change the keg before the line is totally voided, saving time and product.

There are 187,000 kegs in the TBS float which are maintained in-house. About 35,000 kegs are seen every 2.5 years but there is a major renovation project underway which aims to see an extra 65,000 kegs for valve replacement annually.

In the southern Ontario area where line cleaning is offered 59 to 60% of licensees use the service. All of the functions of the DES group are designed with line cleaning subsidies in mind. To this end, cost to the brewers who own "The Beer Store" have dropped from $2.6 million in 1991 to $100,000 in 2003 TBS keg maintenance.