Brewing pH

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Introduction:


How important is the pH and why?

in many ways, pH control throughout the brewing process (from mashing-in to final packaging) is fundamental to achieving end product consistency.[1] The maintenance of control of pH during wort production, fermentation, and conditioning is of great importance to beer quality by ensuring reproducible conditions for the numerous enzymic and chemical reactions occurring during these key beer production stages. In addition, finished beer pH impacts beer flavor as well as physical and microbiological stability.21,22

Because of its influence on the structure of the catalyst molecules, the hydrogen ion concentration is almost as important as the temperature. It is affected by the quality of the brewing liquor, additions of acid and the mash concentration.[2]


What factors affect the pH?

Due to the action of phosphatases, The lowest pH values and also the lowest buffer capacity mean mashing temperatures of 62 to 65 ° C. A decrease in the mash pH leads to increased buffering, which can then weaken the pH drop during fermentation. High calcium contents in the brewing water (due to gypsum or calcium chloride) precipitate phosphates and in turn reduce the buffering of mash and wort.[3]

There are three key buffering systems likely to be influencing wort and beer pH16,21,22:[1]

  • Carbonate/bicarbonate
  • Phosphate; both inorganic and organic (especially phytates)
  • Carboxylic acids (especially aspartate and glutamate side chains in proteins/polypeptides/peptides/free amino acids)

The pH of the brewing water does not matter at all.[4][5][6] Rather, it's the minerals dissolved in the water that are significant because of their influence on pH of the mash, the boil, the fermentation, and ultimately the packaged beer.

Calcium reacts with malt phosphates and amino acids to decrease mash and wort pH.[6] During mashing, the pH decreases due to malt enzymes activity, which releases phosphates from nucleic acids.[7]

Base malt is generally alkaline, and speciality malt is generally acidic.[4]

The degree of grist crush can affect pH. The buffering capacity decreases with a more coarse crush. For example, mash pH may be significantly higher in a mash with a coarse crush. However, it is speculated that this effect should diminish with longer mashing time, as the grist becomes fully hydrated and more initiates are available for reaction.[4]

During the mashing process, the pH of the adjusted mash drifted towards a more natural wort pH: the pH 5.0 mash had an average pH of 5.07, while the pH 6.0 mashes had an average pH of 5.92. This is due to the release of various wort substances during mashing, such as amino nitrogen compounds and organic acids, which have buffering capability. The first and second wort sparges had average gravities of 10.5 ± 0.7°P and 5.7 ± 0.4°P. But here, the opposite effect could be seen with mash pH and extract: the first and second sparges of the spent grain mashed at pH 5.0 had lower extracts on average (10.3°P and 5.4°P) than the ones mashed at pH 6.0 (10.7°P and 5.9°P). This effect was particularly noticeable in the tannic acid sparges (Δ°P of 0.7 between different pHs).[8]

Substances such as phosphates and products of protein breakdown in wort act as salts of weak acids at wort pH. Wort pH is often adjusted by addition of lactic acid but the pH change is relatively small because of the buffering effect. A salt of a strong acid and a strong base (like NaCl, the salt of hydrochloric acid) on the other hand provides no buffering action and adding the acid or the base changes the pH immediately. Buffering capacity is very important in brewing since it controls wort and beer pH.[9]

An important challenge often arises from the practice of measuring wort or mash pH at room temperature and assuming that these values remain constant at higher temperatures, which is not the case, as studies have shown that at 65 °C the pH of a wort can be approximately 0.35 pH units lower than its room temperature measurement.[22,23][10]

It appears that regardless of the pH adjustment at mashing-in, the final pH of the sweet worts gravitated toward the unadjusted wort pH[10]

In general, worts of higher pH range display greater buffering capacity.[6] Several components in wort, such as phosphates, free amino acids, peptides and polypeptides containing residues like aspartate and glutamate, contribute to its buffering capacity.[4,53][10]

the pH of materials such as wort and beer is determined by the concentration and type of buffer substances present, by the absolute concentration of H + and OH - present or introduced and by the temperature. Various materials in wort and beer have buffering capacity, notably peptides and polypeptides containing residues such as aspartate and glutamate. The pKa of the carboxyl groups in the side chains of aspartic acid and glutamic acid residues incorporated into proteins are 3.0 - 4.7 and 4.5 respectively whilst the N in the imidazole group on histidine has a pKa of 5.6 - 7 (Table 1). Accordingly, these groups will be important for establishing buffering at the pH range found in beers and worts.[11]

When and how should pH be measured?

Always measure mash-pH at the same stage in the mashing process: At the beginning of saccharification.[12]

The pH changes based on the temperature. However, pH measurements should always be taken at room temperature and expressed as such. This is easier on the measurement device, and it is the standard in technical documents.[4]

The best a brewer can do to achieve consistent pH control is to find a consistent, high-quality source for malt and focus of brewing water composition, salt and/or acid additions, and consistency of sampling and measurement methods.[4]


Discuss sour beer.

It should be noted that in the case of organic acids, their flavor contributions are not restricted merely to acting as suppliers of H+ ions in order to produce the characteristic sourness, but the structural features of these molecules also determine their flavor threshold.22 For example, organic acids such as acetic, lactic, and citric have very different flavor characteristics, but all contribute to perceived acidic and sour flavors. These effects can be very important in classical acidic beers, such as "Gueuze" and "Lambic" beers.[1]



Effects of pH[edit]

All enzymes have an optimal pH range in which they operate, so naturally, enzyme activity during mashing is greatly affected by the pH level of the mash.[13][3] The recommended mash pH of 5.4 to 5.5 (measured at 20°C) puts the starch-degrading enzymes (α-amylase, β-amylase, and limit dextrinase) within or very close to their respective ideal pH ranges.[13][14][15][8] Because of this, good pH control leads to increased starch breakdown and improved fermentability, leading to a faster and healthier fermentation.[16][4][17][13][3][5][10][8][9][18][19] The mash pH also affects protein degradation, although the pH optima of the proteinases is lower, around 5.0.[3][5][17] Mashing above the optimal protease enzyme range helps to provide just the right amount of protein degration and FAN extraction (we don't want too much).[3][9][19] However, poorly-modified malts may benefit from a slightly lower mash pH to optimize proteolysis, which can improve total extract and FAN when using those malts.[4] The improved degradation of starch and protein by mashing at proper pH increases the extract yield (mash efficiency) and can improve lautering and filtration speed.[16][13][10][20][8][9][18][3][19] The activity of lipoxygenase enzymes is reduced at lower pH values, and therefore proper pH control helps improve flavor stability.[13][14][21][3][22][5][23][24] Lower pH increases the activity of phosphatase enzymes, which is undesirable since the liberation of phosphates increases buffering capacity and results in higher final beer pH.[13][3] However, phosphatases are inactivated at 62°C, and so this is not a concern for brewers that implement a modern mash schedule. Lastly, controlled pH increases the breakdown of β-glucans to a mild extent.[3]

During both mashing and boiling, pH control has a beneficial effect on the precipitation of wort proteins, often called "break" formation.[18][13][3][8] This results in better colloidal stability (i.e. less chance of becoming hazy during storage).[13][24][14][17] Furthermore, the improved trub sedimentation makes the break material easier to remove, and allows transfer of a more clear wort into the fermentation vessel. More clarified wort helps improve fermentation performance and beer pH control, since the excess protein acts as an unwanted pH buffer in the fermentation vessel.[13][3] However, if the pH of kettle wort is too low after boiling (less than 5.0), break formation becomes worse, leading to high losses or increased trub carryover to the fermenter.[24][5][25] Despite increased protein coagulation, proper pH helps reduce the formation of gel-protein (particularly in a mash exposed to oxygen), another mechanism that increases lautering speed.[26]

Lowered pH during mashing and lautering leads to decreased extraction of undesirable phenolic compounds (i.e. "tannins") and silica compounds from the malt.[9][15][1][27][8][4] Reduced extraction of these components results in wort and beer with lighter color, less astringency, and less harsh bitterness.[13][10][14][16][3][1][17][19] Similarly, the pH value influences the solubility of hop components; α-acids are less soluble at lower pH and isomerization is slower.[14][1][16][3] Lower pH in boiling reduces hop utilization (reducing hop bitterness and expression), and therefore it may be necessary to increase the amount of hops when lowering the pH.[3][4][17][1] The flavor of pH controlled beer is described as fresher, softer, mellower, and more satisfyingly full-bodied, with a pleasingly rounded character.[13][28][17][16] The hop bitterness is more pleasant and does not linger.[13][3][1] Uncontrolled high pH can negatively affect hop bitterness, making it "biting and crude", "rough and scratchy", and "harsh", and will also result in a beer with dull, one-dimesional malt flavors.[4][15][21][3]

A lower pH during mashing increases the extraction of certain metals during mashing (calcium, magnesium, iron, manganese, and zinc).[8][10][13][29][19] The improved extraction of zinc is beneficial since it is an important yeast nutrient.[13] Despite the increase in transition metal extraction, controlling mash pH is still shown to improve the redox potential, making the wort and beer less susceptible to oxidation.[13][10] Of course, pH control alone doesn't prevent oxidation during the mash[26] — other methods are also required to avoid the damage from oxygen. Not all metals have increased extraction at lower pH;[8] sodium and copper extraction peak within 5.5-5.7 and potassium extraction is relatively unaffected by mash pH.[29]

The pH during fermentation can make a sizeable impact on the production of flavor components by yeast.[1] A lower pH in the finished beer increases yeast flocculation, further improving beer clarity.[17] While it helps brewers yeast, lowered pH simultaneously improves the beer's resistance to spoilage microorganisms.[9]

The foam stability of the beer is improved by good pH control.[13][14][16]

The pH of beer has a direct impact on flavor.[1][9] At pH values below 4.0, beers tend to taste sharper and acidic, with an increased drying after-palate and a tendency for perceived bitterness to be enhanced.[1] At pH 3.7 and below, these effects rapidly increase in intensity, with markedly enhanced metallic after-palates.[1] Above pH 4.0, the palate effects relate to increased mouth-coating, with enhanced scores for biscuit and toasted characters.[1] At pH 4.4 and above, the mouth-coating effects become increasingly more accentuated, with soapy, and even caustic, characters developing.[1]

Summary of the benefits of pH control:

  • Improved extraction yield (efficiency)
  • Faster lautering
  • Improved fermentation performance
  • Improved flavor — fresher, more full-bodied and rounded, softer more pleasant bitterness, more defined malt flavors, and less astringency
  • Improved flavor stability
  • Improved beer clarity
  • Lighter beer color
  • Improved beer foam
  • Improved resistance to spoilage organisms

Mash pH control[edit]

Mashing is the key point for controlling the pH throughout the brewing process.[1][30] For good mash performance, the pH is almost as important as the temperature.[2] The ideal mash pH is 5.4 to 5.5 (measured at room temperature),[13][2][16][31] although mash pH anywhere in the range of 5.2 to 5.6 may be considered acceptable.[5][1][32][6][21][4][33]

The pH of the mash will shift over time,[4] so it is important to take the measurement sample early in the mash when the vast majority of enzyme activity is occurring. Likewise, the mash pH should be controlled as early as possible in order to optimize the enzyme activity and inhibit LOX.[13] Usually the mash pH is adjusted only once at the onset of mashing.[21] Adjusting the pH later in the mash will have less benefit since enzyme activity will be much lower. The possible exception to this is when mashing below 60°C since proteolysis is promoted by lowering the pH value, which may be undesirable.[13]

Methods to lower mash pH
Additive Positives Negatives
Non-alkaline calcium or magnesium salts, such as calcium chloride, calcium sulfate, or magnesium sulfate Calcium additions have a more synergistic affect on mash performance as a whole versus other acid additions.[4] Salts can be difficult to measure correctly due to the small quantities required for home brewers, and calcium chloride in particular can be difficult to measure correctly because it absorbs water from the air during storage.
Pure food-grade acid, such as lactic acid or phosphoric acid Relatively easy to use. Phosphoric acid addition leads to the formation of phosphates, which promote a vigorous fermentation.[16] Liquid acids are useful for adjusting pH during boiling. Handling concentrated phosphoric acid is moderately hazardous.[citation needed] Lactic acid can have a negative impact on flavor.[citation needed] Lactic acid can increase wort buffering capacity, and this risks an increase in beer pH.[1][19][10]
Acidulated malt Easy to use. Not useful for neutralizing alkalinity in sparge water or for lowering pH during boiling. Acid content can vary (to a limited extent).[12]
Wort soured by lactic acid bacteria (sauergut); this method is called biological acidification Produces the best sensory characteristics.[13][31] Creating and measuring the acidity of the sour wort requires additional labor (unless you buy it).


Regardless of the chosen method to lower pH, it is generally suggested to begin with water containing low bicarbonate (less than 50 mg/L and ideally less than 20 mg/L).[1][17][32][9]

For beers with a high amount of dark malts, it may be necessary to increase mash pH to achieve the ideal level, typically accomplished by increasing water alkalinity (bicarbonate). In this case, an addition of sodium bicarbonate (baking soda) to the strike water is the preferred method.[4] Keep in mind that alkalinity should never be added to sparge water.

Modern brewers have access to a variety of tools to help determine how much of your preferred acid/base product is needed to achieve the ideal mash pH based on the characteristics of the recipe's grain bill and the preexisting water minerals.

FYI - Historically, the concept of Residual Alkalinity (RA) was useful as a general guideline for achieving a proper mash pH depending on the beer style. Calculating RA involves looking at the amounts of calcium and magnesium (which lowers mash pH) and the amount of bicarbonate (which raises mash pH) and determining the combined effect that these water ions will have on the mash, expressed as a numerical value.[34][4] A positive RA value indicates that the water will increase the pH, a negative RA will lower pH, and a zero RA value will have no effect but instead mash pH will depend entirely on the characteristics of the grain.[32] The usage of residual alkalinity values is essentially obsolete nowadays since brewers have more accurate methods of predicting mash pH by using calculators that account for the specific grain types and amounts in the recipe.

FYI - Historically, a step-mash rest at 35–40°C was called the acid rest since phosphatases and other acid-forming enzymes are active in this temperature range. However, practical experience has shown that the mash pH is quickly established and then is held in check from that point forward by strong buffering agents in the mash. Thus, it is not a useful method for controlling mash pH.[15]

Sparging[edit]

Controlling the pH (in particular, keeping the pH low) during sparging is especially important for beer quality. Continually rinsing the grain with water containing alkalinity has a strong tendency to increase the pH of the wort being extracted, since the beneficial buffering agents are drained with the first runnings.[21][1] A pH increase at this point can lead to increased extraction of foul-tasting materials from the grain bed such as silicates/silica compounds and phenolic compounds/polyphenols (mainly from malt husks).[1][5] Because of this, sparge water should ideally contain very low alkalinity and/or it should contain higher amounts of calcium or acid additions to neutralize any alkalinity present.[21][1]

Boil pH control[edit]

The pH of the wort during boiling is important factor for the effectiveness of protein precipitation (called break formation) and extraction of pleasant bitter compounds from hops (called hop utilization).[24] If the wort pH was previously adjusted during mashing/sparging, the wort pH should be at a suitable value at the beginning of the boil, although it should be adjusted toward the end of the boil. During boiling, the pH of wort naturally decreases by about 0.3 units due to the precipitation of phosphates and proteins/polypeptides bound with calcium.[1][7] Wort gravity will have a significant influence on wort pH, with pH lowering as the gravity increases (notable for high gravity brewing).[1] Hop bitter acids and Maillard reaction products also contribute toward lowering the pH.[7]

Shortly before the end of the boil, it is recommended to acidify the wort in the kettle to a pH of 5.1 to 5.2 by adding acid or sour wort.[16][13][24][1] Achieving this pH target is beneficial to maximize the formation and subsequent removal of hot break.[24] Lowering the pH at this stage also helps achieve an appropriate pH for the final beer (after fermentation).[16][9] Delaying the acidification (rather than acidifying the wort toward the beginning of the boil) allows better hop utilization and better DMS removal, which are both promoted by higher pH.[13][1]

pH change during fermentation[edit]

The pH falls during fermentation as a result of the consumption of buffering materials—principally FAN, the release of organic acids, and possibly the direct excretion of H+ ions by yeast.21,22,32 The nature and content of buffering materials present in wort collected in the fermenter will be a direct consequence of pH control during wort production.[1] The rate and extent of the pH decrease during fermentation are a balance between buffering capacity and the factors stimulating yeast growth. Increased yeast growth reduces pH.

Higher the pH on the scale 4–4.5, the lower the level of the most damaging oxygen species in beer.[35]

Yeast growth occurs over the pH range from 2.8-8.0 (19). However, cultures do not function equally well throughout this wide range. Biomass is produced best above pH 4.0 and slows as pH goes down. Low pH reduces the tolerance of Saccharomyces sp. to ethanol. Kudo, et al. (22) demonstrated a relationship between the concentrations of K+ and H+ and the completion of alcoholic fermentation. They suggested that a minimum K+ / H+ of 25:1 is required. As pH drops below 3.2, the increase in H+ raises the risk of premature arrest of fermentation. Added stress is placed on yeast at low pHs and is compounded by low nutrient concentrations, temperature extremes, high sugar and/or high alcohol. Additionally, highly chaptalized juice has a limited buffering capacity. As a result, the organic acid and CO2 production during the initial stage of fermentation can drop the pH (Cone, personal communication, 1995). Juice/musts with pH <3.1 should receive an increased yeast inoculum.[36]

When fermenting, the pH declines by the activity of yeasts that consume amino acids and produce organic acids. The pH also changes because of presence of the carbon dioxide, which dissolves in the solution (Basařová et al., 2010).[7]

In general the pH decreases by about 1 pH unit during fermentation. 5.2 pH pitching wort thus usually gives a beer with a pH of about 4.2.[9]

Finished beers with pH-values at or below 4.4 have greater foam stability and head retention than those with values of 4.5 and above. Sensory studies show that acidulated beers receive higher sensory ratings and consumer acceptance than do non-acidulated beers. Consumers tend to describe acidulated beers as “tasty,” “fresh,” “palatable,” “balanced,” “drinkable,” and “pleasantly bitter.”[12]

Target pH values for select styles[12] Czech Pilsner and Bock pH 4.50 – 4.80 Kölsch and Alt pH 4.15 - 4.40 Bavarian Hefeweizen pH 4.10 – 4.40 English Ales pH 4.00 – 4.20 Lambic pH 3.40 – 3.90 Gueuze and Framboise pH 3.30 – 4.50 Berliner Weisse pH 3.20 - 3.40

Factors that stimulate yeast growth generally lead to lower beer pH. These include agitation during fermentation, higher oxygenation at pitching, higher temperature, higher FAN, and higher zinc. By contrast anything leading to lower yeast growth will typically cause higher beer pH. Different yeast strains also have differing effects on pH.[11]


See also[edit]

Potential sources[edit]


References[edit]

  1. ↑ a b c d e f g h i j k l m n o p q r s t u v w x y z Taylor DG. Water. In: Stewart GG, Russell I, Anstruther A, eds. Handbook of Brewing. 3rd ed. CRC Press; 2017.
  2. ↑ a b c Sacher B, Becker T, Narziss L. Some reflections on mashing – Part 1. Brauwelt International. 2016;5:309-311.
  3. ↑ a b c d e f g h i j k l m n o p Narziss L, Back W, Gastl M, Zarnkow M. Abriss der Bierbrauerei. 8th ed. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA; 2017.
  4. ↑ a b c d e f g h i j k l m n o Palmer J, Kaminski C. Water: A Comprehensive Guide for Brewers. Brewers Publications; 2013.
  5. ↑ a b c d e f g Evans E. Mashing. American Society of Brewing Chemists and Master Brewers Association of the Americas; 2021.
  6. ↑ a b c Lewis A. The low down on water softeners for brewing. Brew Your Own website. 2020. Accessed online 2024.
  7. ↑ a b c d Punčochářová L, Pořízka J, Diviš P, Štursa V. Study of the influence of brewing water on selected analytes in beer. Potravinarstvo. 2019;13(1):507–514.
  8. ↑ a b c d e f g h Mertens T, Kunz T, Wietstock PC, Methner FJ. Complexation of transition metals by chelators added during mashing and impact on beer stability. J Inst Brew. 2021;127(4):345–357.
  9. ↑ a b c d e f g h i j Kallmeyer M. To mash or not to mash Kurz/Hoch. Drayman's Brewery website. 2016. Accessed online March 2024.
  10. ↑ a b c d e f g h i Ditrych M, Mertens T, Filipowska W, et al. Effect of mashing-in pH on the biochemical composition and staling properties of the sweet wort. J Am Soc Brew Chem. 2024;82(3):238–251.
  11. ↑ a b Bamforth CW. pH in brewing: An overview. Tech Q Master Brew Assoc Am. 2001;38(1):1–9.
  12. ↑ a b c d Kraus-Weyermann T. pH in the Brewery: A Much Underestimated Brewing Variable (slides). Weyermann Malting Company. Bamberg, Germany. Accessed online April 2025.
  13. ↑ a b c d e f g h i j k l m n o p q r s t u v Kunze W. Wort production. In: Hendel O, ed. Technology Brewing & Malting. 6th ed. VLB Berlin; 2019:219–265.
  14. ↑ a b c d e f Pahl R, Meyer B, Biurrun R. Wort and Wort Quality Parameters. In: Bamforth CW, ed. Brewing Materials and Processes: A Practical Approach to Beer Excellence. Academic Press; 2016.
  15. ↑ a b c d Fix G. Principles of Brewing Science. 2nd ed. Brewers Publications; 1999.
  16. ↑ a b c d e f g h i j Miedl-Appelbee M. Brewhouse technology. In: Stewart GG, Russell I, Anstruther A, eds. Handbook of Brewing. 3rd ed. CRC Press; 2017.
  17. ↑ a b c d e f g h Howe S. Raw materials. In: Smart C, ed. The Craft Brewing Handbook. Woodhead Publishing; 2019.
  18. ↑ a b c Montanari L, Mayer H, Marconi O, Fantozzi P. Chapter 34: Minerals in beer. In: Preedy VR, ed. Beer in Health and Disease Prevention. Academic Press; 2009:359–365.
  19. ↑ a b c d e f Reiter T, Back W, Krottenthaler M. Effects of mash acidification. Brew Sci. 2008;62(Nov/Dec):1–13.
  20. ↑ Jones BL, Budde AD. How various malt endoproteinase classes affect wort soluble protein levels. J Cereal Sci. 2005;41(1):95–106.
  21. ↑ a b c d e f Briggs DE, Boulton CA, Brookes PA, Stevens R. Brewing Science and Practice. Woodhead Publishing Limited and CRC Press LLC; 2004.
  22. ↑ Golston AM. The impact of barley lipids on the brewing process and final beer quality: A mini-review. Tech Q Master Brew Assoc Am. 2021;58(1):43–51.
  23. ↑ De Rouck G, Jaskula B, De Causmaecker B, et al. The influence of very thick and fast mashing conditions on wort composition. J Am Soc Brew Chem. 2013;71(1):1–14.
  24. ↑ a b c d e f Withouck H, Boeykens A, Jaskula-Goiris B, et al. Upstream beer stabilisation during wort boiling by addition of gallotannins and/or PVPP. Brew Sci. 2010;63(1-2):14–22.
  25. ↑ Jin YL, Speers RA, Paulson AT, Stewart RJ. Effects of β-glucans, shearing, and environmental factors on wort filtration performance. J Am Soc Brew Chem. 2004;62(4):155–162.
  26. ↑ a b Pöyri S, Mikola M, Sontag-Strohm T, Kaukovirta-Norja A, Home S. The formation and hydrolysis of barley malt gel-protein under different mashing conditions. J Inst Brew. 2002;108(2):261–267.
  27. ↑ Gibson BR. 125th anniversary review: improvement of higher gravity brewery fermentation via wort enrichment and supplementation. J Inst Brew. 2011;117(3):268–284.
  28. ↑ Sacher B, Becker T, Narziss L. Some reflections on mashing – Part 2. Brauwelt International. 2016;6:392-397.
  29. ↑ a b Holzmann A, Piendl A. Malt modification and mashing conditions as factors influencing the minerals of wort. J Am Soc Brew Chem. 1977;35(1):1–8.
  30. ↑ Taylor DG. The importance of pH control during brewing. Tech Q Master Brew Assoc Am. 1990;27(4):131–136.
  31. ↑ a b Lowe DP, Ulmer HM, Barta RC, Goode DL, Arendt EK. Biological acidification of a mash containing 20% barley using Lactobacillus amylovorus FST 1.1: Its effects on wort and beer quality. J Am Soc Brew Chem. 2005;63(3):96–106.
  32. ↑ a b c Eumann M. Chapter 9: Water in brewing. In: Bamforth CW, ed. Brewing: New Technologies. Woodhead Publishing; 2006:183–207.
  33. ↑ Piper D, Jennings S, Zollo T. Pro-tips on lager decoction mashing, infusion mashing, yeast handling & sauergut (video). YouTube. Published 2022. Accessed 2024.
  34. ↑ Eumann M, Schildbach S. 125th Anniversary review: Water sources and treatment in brewing. J Inst Brew. 2012;118:12–21.
  35. ↑ Bamforth CW, Lentini A. The flavor instability of beer. In: Bamforth CW, ed. Beer: A Quality Perspective. Academic Press; 2009:85–109.
  36. ↑ Gump BH, Zoecklein BW, Fugelsang KC. Prediction of prefermentation nutritional status of grape juice: The formol method. Food Microbiology Protocols. 2001:283–296.
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