Analytical 2:

Analytical 2:

TALK 1: Recent discoveries in beer foam, Karl Siebert, Cornell

Best foam seen with lowest pH (3.?) and mid-range ethanol (5%), in an ovalbumin, isoalpha acid model system. Very simplified, so not totally accurate.

Above pH data was disputed in a study with actual beer (more foam at higher pH), so something was missing in the model system.

With an unmalted barley protein extraction, a higher pH and mid-range ethanol showed most foam, proving a better system than the ovalbumin model.

Seems like LTP1 protein is the main protein involved, and the interactions are mostly hydrogen bonding.

?s: should use malted barley as changed in proteins occur. Yes, I’m not done with this research yet. LTP1 has been shown to be responsible for gushing, does this disprove that? It may be a matter of degree, where normal beer hs the right conditions for moderate foam production.

TALK 2: Critical review of the measurement of carbon dioxide in packaged beer, Donald Hutchison, AB-InBev

Most instruments use pressure/temperature method. Must attemporate and equilibrate sample, correct for air altitude, and package volume.

TALK 3: CO2 solubility in wort and beers, R. Alex Speers, Dalhousie University

When is the beer saturated with CO2 (when bubble formation starts in fermentation)? pH, sugar, ethanol effects?

ASBC measurement is based on undefined reference standard beer, (sg 1.01, changed 1.015 for unknown reason. No chart or formula has provided justification. No presentation of data analysis of error. Formula says

ASBC method possibly used 95% of the value of CO2 solubility in water.

CO2 is 10x more soluble in ethanol than in water, so why does higher etoh content in beer have a negative influence on solubility as per the formulas?

(Findley, Shen, 1911, J. Chem Trans). The only report on CO2 solubility in beer?!

Why do we measure CO2 at higher temps? More accurate for reading gauges.

Need a tested and unified method, which includes factors for pH, ethanol, and extract, not just T and P.

?s: some reports on solubility ARE available, different formulas are available in the soft drink industry, although they also can’t establish origin. Now, ASBC methods have to be based on published papers. Have you investigated how large differences have to be until we can perceive differences in carbonation? Very small study showed no perceived visual differences from 2.2-2.7vol. (visual only?!?).

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4 responses to “Analytical 2:

  1. Pingback: Kort nyt: Vejle Bryghus, United Beverage, Fjordens Bryghus, Hornbeer, BarleyWine osv.

  2. I am sure you are very busy at the WBC but when you get a chance can you explain a little more to me about measuring CO2 for a small brewery? All I do is take a Zahm reading off of the brite tank pre packaging and I use only temp and the pressure on the guage to determine CO2 volume. I am at 6,000 feet elevation and I didn’t know I needed to correct for altitude. Do you have a formula you can give me to correct my reading so that it is more accurate? Thanks again for the very informative website.
    Cheers!

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