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Mash Ph
Posted: Tue Dec 20, 2016 11:13 am
by Natebriscoe
I have been reading through Kunze and see the recommendation to mash at 5.2, but have yet to find the reasoning. Seems the ideal beta and alpha ph are a bit higher than 5.2.
Re: Mash Ph
Posted: Tue Dec 20, 2016 3:52 pm
by caedus
He says a few times that the lower pH helps inhibit LOX reactions. Take a small hit on efficiency (probably less than 1-2% total extract is lost), and have a more shelf stable beer with fresher flavors. I will cruise through and see if I can find an actual page and reference.
Re: Mash Ph
Posted: Tue Dec 20, 2016 4:19 pm
by caedus
Kunze 3.2.1.8 Wort Production (page 237 in V5).
An important measure is mash acidification at the beginning of the mashing process and/or acidification of the wort. The advantages are:
• the range of enzymes is considerably improved because all the important enzymes, with the exception of p-amylase, are activated,
• at low pH-values more growth promoting substances go into solution, e.g. the supply of zinc is increased,
• the extract yield is increased,
• the protein excretion improves (better break formation),
• the redox potential improves, a reduced susceptibility to oxygen thereby develops,
• lautering proceeds faster,
• colouring during wort boiling is suppressed,
• the activity of the phosphatases is promoted and they strengthen the buffering capacity through the release of phosphates,
• fermentation is faster due to better trub excretion, a faster drop in the pH and higher degree of attenuation in the cellar,
• filtration is improved by lower viscosity values,
• the flavour is mellower, fuller and softer,
• the hop bittering is more pleasant and does not linger,
• the beer is fresh, and has a fresher, stronger and more characteristic taste,
• the foam has finer bubbles and is more stable,
• the colour of the beer is lighter,
• a better flavour stability is to be expected, particularly as the lipoxygenase is sensitive to pH values below 5.2 and is then no longer effective
• the chemical-physical stability is better, less tendency to protein haze,
• digestion is aided, which is a positive effect of the lactic acid,
• reduction of the biological susceptibility of the beer because of:
• the low pH : beer spoiling organisms no longer grow below a pH of 4.4,
• the higher degree of attenuation leading to a lower amount of non-fermentable sugar, and hence
• a greater pressure towards selectivity of the yeast which forces back the beer-spoiling competitors.
Section 5.2.1.6:
short mashing in time and low mash pH value of 5.1-5.2 reduce the LOX activity.
Hope that helps
Re: RE: Re: Mash Ph
Posted: Tue Dec 20, 2016 4:49 pm
by Natebriscoe
Re: Mash Ph
Posted: Tue Dec 20, 2016 4:55 pm
by Natebriscoe
So what would everyone's thoughts be on a beer that should have a roast character? I find that I like the ph 5.4-5.6 from a flavor stand point. Maybe some antioxidant buffering from the roast malt to allow a higher ph?
Re: Mash Ph
Posted: Tue Dec 20, 2016 5:45 pm
by caedus
You could always mash at 5.2, then raise which chalk later.
Or use only your base/crystal malt, mash at 5.2. Then mash/steep your roasted malts separately and add them to kettle as your kettle acidification addition, targeting 4.9.
Re: Mash Ph
Posted: Wed Dec 21, 2016 11:13 pm
by Weizenberg
It really depends.
Hefebank Weihenstephan published a paper stating that the biological mash acidification to 5.4 had the best sensory results.
Those familiar with Narziss and Beck will recognise a pH of 5.4-5.5 cited in all the examples. Further acidification then occurs 15 min before boil end and sometimes even after the protein break (5.1-5.2).
What suits one's tastes is naturally a matter of personal preference. I doubt an experiment at 2 different pH settings will burst any homebrewer's bank.
Re: Mash Ph
Posted: Wed Dec 21, 2016 11:17 pm
by Weizenberg
Re: Mash Ph
Posted: Wed Feb 15, 2017 3:59 pm
by Natebriscoe
Was listening to a probrewer podcast today on malting. Where it was stated that if the malt kilning reaches 180f, lox is denatured and no longer an issue. I would bet a lot of malts we use reaches 180f.
Maybe, the 5.2 ph may not be necessary for lox reasons.
Re: Mash Ph
Posted: Wed Feb 15, 2017 4:15 pm
by Bryan R