Finn Berger
Moderator
Slutt pHen er vel minst like interessant. Er vel bare "halvparten" vits å styre med pH hvis man bare gjør det under mesking.
Her er hva Kunze - referert av Braukaiser - sier:
A commonly accepted optimal range for mash pH is 5.2 - 5.7 with 5.5 being optimal for starch conversion activity but many authors report wort and beer quality benefits if the pH is lowered into the 5.2 - 5.4 range [Kunze, 2007][Narziss, 2005]. Kunze in particular lists the following benefits for a mash pH as low as 5.2. Since it is a good and fairly comprehensive list I cited it here. Some of these benefits listed will be explained in the following sections [Kunze, 2007]:
- The enzymatic activity in the mash is increased as all important enzymes get activated. (except for alpha amylase which starts to suffer at a pH below 5.6)
- More zinc, an essential yeast nutrient, goes into solution
- The extract yield (efficiency) is improved
- The protein coagulation and precipitation is improved (improved break formation)
- The redox potential is improved which results in a lower susceptibility to oxygen.
- The run-off speed is improved
- The color increase during the wort boil is reduced
- Better trub precipitation and faster pH drop lead to faster fermentation and greater attenuation of the beer.
- Lover viscosity improves filterability
- The taste of the beer is more rounded, fuller and softer. The beer is crisper, more fresh and shows more character.
- The hop bitterness is more pleasant and doesn't linger
- The foam is more stable and denser
- The color of the beer is lighter
- Mash oxidation is reduced since the main culprit, the lipoxigenase enzyme, doesn't work well at low mash pH conditions
- Haze stability is improved
- Beer digestion is stimulated. This is a positive effect of the lactic acid
- Susceptibility to microbial spoilage is reduced through
- Lower beer pH: beer spoilage organism don't grow below a pH of 4.4
- Higher attenuation