Editing Calcium

[[File:Calcium-periodic-symbol.png|right|alt=Calcium periodic table emblem|link=]]
Calcium (Ca<sup>2+</sup>) is a mineral naturally present in [[water]] and [[grain]]. It is one of the most important components of brewing water due to its effects on mashing [[enzymes]], [[brewing pH|pH control]], and [[haze|clarification]].<ref name=bmp5>Eumann M, Schaeberle C. Water. In: Bamforth CW, ed. [[Library|''Brewing Materials and Processes: A Practical Approach to Beer Excellence.'']] Academic Press; 2016.</ref><ref name=water/><ref name=comrie>Comrie AA. [https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.2050-0416.1967.tb03050.x Brewing liquor—a review.] ''J Inst Brew.'' 1967;73(4):335–346.</ref><ref name=smart1>Howe S. Raw materials. In: Smart C, ed. [[Library|''The Craft Brewing Handbook.'']] Woodhead Publishing; 2019.</ref> Calcium additions may be necessary if the level in the water is too low. The recommended calcium level in brewing water is 50–150 mg/L.<ref name=water/><ref name=fix/><ref name=bsp/><ref name=mashing>Evans E. [[Library|''Mashing.'']] American Society of Brewing Chemists and Master Brewers Association of the Americas; 2021.</ref><ref>Goode DL, Halbert C, Arendt EK. [https://www.tandfonline.com/doi/abs/10.1094/ASBCJ-61-0069 Optimization of mashing conditions when mashing with unmalted sorghum and commercial enzymes.] ''J Am Soc Brew Chem.'' 2003;61(2):69–78.</ref><ref>Bajomo MF, Young TW. [https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.2050-0416.1992.tb01138.x Development of a mashing profile for the use of microbial enzymes in brewing with raw sorghum (80%) and malted barley or sorghum malt (20%).] ''J Inst Brew.'' 1992;98(6):515–523.</ref><ref name=pejmoj>Pejin JD, Mojović LV, Pejin DJ, et al. [https://www.sciencedirect.com/science/article/pii/S0016236114010722 Bioethanol production from triticale by simultaneous saccharification and fermentation with magnesium or calcium ions addition.] ''Fuel.'' 2015;142:58–64.</ref><ref name=eumsch/> On the other hand, excessive levels (>250 mg/L) may impair [[fermentation]] by removing too much [[phosphates|phosphate]] during brewing or by inhibiting [[magnesium]] uptake by the [[yeast]].<ref name=salsla>Saltukoglu A, Slaughter JC. [https://onlinelibrary.wiley.com/doi/abs/10.1002/j.2050-0416.1983.tb04151.x The effect of magnesium and calcium on yeast growth.] ''J Inst Brew.'' 1983;89(2):81–83.</ref><ref name=water/><ref name=bsp/><ref name=fix/><ref name=smart1/><ref name=gib125/> In extremely high concentrations, it causes [[haze]] in beer.<ref name=smart1/> Calcium is essentially flavor-neutral (it has no flavor), although it can reduce the somewhat sour flavor of [[magnesium]].<ref name=bsp/><ref name=smart1/><ref name=water/><ref name=hob>Taylor DG. Water. In: Stewart GG, Russell I, Anstruther A, eds. [[Library|''Handbook of Brewing.'']] 3rd ed. CRC Press; 2017.</ref> Partly due to the its content of calcium along with other minerals and essential nutrients, beer has a higher nutritional value than other alcoholic beverages.<ref name=soliva>Solgajová M, Ivanišová E, Nôžková J, Frančáková H, Tóth Ž, Dráb Š. [https://www.proquest.com/openview/0a0ccd3ae387c2d4a4db31f29bec1614/1 Antioxidant activity and polyphenol content of malt beverages enriched with bee pollen.] ''J Microbiol Biotech Food Sci.'' 2014;3(3):281–284.</ref> Calcium is classified as an alkaline-earth metal.

'''Beer calcium content:''' Commercial beers typically have around 35 to 40 mg/L calcium.<ref name=kunze>Kunze W. Hendel O, ed. [[Library|''Technology Brewing & Malting.'']] 6th ed. VLB Berlin; 2019.</ref> This is relatively low because only about half of the calcium ions in the mashing water (from the source water and/or added via salts) pass to the final beer. The other half is lost with the [[spent grains]] and [[trub]].<ref name=bsp/><ref name=hob/>

== Potential sources of calcium ==
The calcium content in beer comes from the raw ingredients, mainly the water and grist, plus any salts added by the brewer.
* '''Brewing water''' - The [[water]] used to make beer may contain dissolved calcium. In the US and Canada, the calcium level in municipal tap water typically varies from 1 to 135 mg/L.<ref>Morr S, Cuartas E, Alwattar B, Lane JM. [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2488164/ How much calcium is in your drinking water? A survey of calcium concentrations in bottled and tap water and their significance for medical treatment and drug administration.] ''HSS Journal.'' 2006;2(2):130–135.</ref><ref name=azogar>Azoulay A, Garzon P, Eisenberg MJ. [https://onlinelibrary.wiley.com/doi/full/10.1111/j.1525-1497.2001.04189.x Comparison of the mineral content of tap water and bottled waters.] ''J Gen Intern Med.'' 2001;16(3):168–175.</ref><ref name=burdie>Burlingame GA, Dietrich AM, Whelton AJ. [https://awwa.onlinelibrary.wiley.com/doi/abs/10.1002/j.1551-8833.2007.tb07930.x Understanding the basics of tap water taste.] ''J Am Water Works Assoc.'' 2007;99(5):100–111.</ref> Calcium levels in private well water can be higher, as much as 400 mg/L or more.<ref>[https://epi.dph.ncdhhs.gov/oee/docs/TotalHardnessCalciumMagnesiumAndPrivateWells.pdf Total hardness, calcium, magnesium & private wells.] NC Department of Health and Human Services fact sheet. 2019. Accessed online April 2024.</ref> Purified water (RO, distilled, or deionized) does not contain calcium. Loss of calcium can occur prior to mashing if the water is pre-boiled (e.g. as one possible option to deaerate the water).<ref name=comrie/>
* '''Grain''' - [[Malt]] calcium concentrations typically range from 180 to 1,600 mg/kg, with the high variability likely due to differences in conditions such as soil, fertilizer usage, and the steeping liquor used during [[malting]].<ref name=gib125>Gibson BR. [https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.2050-0416.2011.tb00472.x 125th anniversary review: improvement of higher gravity brewery fermentation via wort enrichment and supplementation.] ''J Inst Brew.'' 2011;117(3):268–284.</ref><ref name=hob/> Approximately 25–50% of malt calcium is extracted into the wort during [[mashing]], adding around 15 to 35 mg/L Ca<sup>2+</sup>.<ref name=gib125/> The amount extracted appears to be related to the solubility of the malt calcium, rather than the total amount present.
* '''Salt additives''' - Brewers can enrich the calcium level of the wort during [[mashing]] or [[boiling]] by adding brewing salts that contain calcium, such as [[calcium chloride]] and [[calcium sulfate]]. This is commonplace for optimizing water chemistry.

== Effects of calcium ==
In the context of brewing beer, calcium has several important effects.

* '''Improved mash enzyme function''' - Calcium protects, stabilizes, and promotes [[enzymes|enzyme]] activity in the mash, especially α-amylase.<ref name=mashing/><ref name=bsp>Briggs DE, Boulton CA, Brookes PA, Stevens R. [[Library|''Brewing Science and Practice.'']] Woodhead Publishing Limited and CRC Press LLC; 2004.</ref><ref name=water/><ref name=smart1/><ref name=eumsch/><ref name=pejmoj/><ref>Evans DE, Collins H, Eglinton J, Wilhelmson A. [https://www.researchgate.net/publication/230559002_Assessing_the_impact_of_the_level_of_diastatic_power_enzymes_and_their_thermostability_on_the_hydrolysis_of_starch_during_wort_production_to_predict_malt_fermentability/link/5789973608ae5c86c99ae90f/download Assessing the impact of the level of diastatic power enzymes and their thermostability on the hydrolysis of starch during wort production to predict malt fermentability.] ''J Am Soc Brew Chem.'' 2005;63(4):185–198.</ref><ref>Bertoft E, Andtfolk C, Kulp SE. [https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.2050-0416.1984.tb04278.x Effect of pH, temperature, and calcium ions on barley malt α‐amylase isoenzymes.] ''J Inst Brew.'' 1984;90(5):298–302.</ref><ref>Bush DS, Sticher L, Van Huystee R, Wagner D, Jones RL. [https://www.jbc.org/content/264/32/19392.full.pdf The calcium requirement for stability and enzymatic activity of two isoforms of barley aleurone α-amylase.] ''J Biol Chem.'' 1989;264(32):19392–19398.</ref><ref name=fix>Fix G. [[Library|''Principles of Brewing Science.'']] 2nd ed. Brewers Publications; 1999.</ref><ref name=hob/><ref name=evans>Evans DE, Fox GP. [https://www.tandfonline.com/doi/abs/10.1094/ASBCJ-2017-4707-01 Comparison of diastatic power enzyme release and persistence during modified Institute of Brewing 65°C and Congress programmed mashes]. ''J Am Soc Brew Chem.'' 2017;75(4):302–311.</ref> Promotion of α-amylase can potentially lead to increased [[extract]] and improved [[attenuation]] by improving starch degradation (see [[Starch]]).<ref>Taylor JR, Daiber KH. [https://onlinelibrary.wiley.com/doi/pdf/10.1002/j.2050-0416.1988.tb04559.x Effect of calcium ions in sorghum beer mashing.] ''J Inst Brew.'' 1988;94(2):68–70.</ref><ref name=hob/> Promotion of endopeptidase can increase the [[FAN]] levels in wort (see [[Protein]]).<ref name=hob/>
* '''Improved pH control''' - Calcium beneficially lowers the [[brewing pH|pH]] during mashing by precipitating with [[phosphates]] and other compounds.<ref name=monmay>Montanari L, Mayer H, Marconi O, Fantozzi P. [https://www.sciencedirect.com/science/article/abs/pii/B9780123738912000341 Chapter 34: Minerals in beer.] In: Preedy VR, ed. [[Library|''Beer in Health and Disease Prevention.'']] Academic Press; 2009:359–365.</ref><ref name=water>Palmer J, Kaminski C. [[Library|''Water: A Comprehensive Guide for Brewers.'']] Brewers Publications; 2013.</ref><ref name=bsp/><ref name=bmp5/><ref name=eumsch>Eumann M, Schildbach S. [https://onlinelibrary.wiley.com/doi/pdf/10.1002/jib.18 125<sup>th</sup> Anniversary Review: Water sources and treatment in brewing.] ''J Inst Brew.'' 2012;118(1):12–21.</ref><ref name=hob/> Mash pH control has many beneficial effects, see [[Brewing pH]].
* '''Improved protein coagulation''' - Calcium promotes protein coagulation during [[mashing]] and [[boiling]], which leads to faster [[lautering]], formation of a good hot break ([[trub]]), and improved beer clarification.<ref name=eumsch/><ref name=water/><ref name=bsp/><ref name=hob/><ref name=fix/>
* '''Lowered oxalate''' - Calcium combines with [[oxalic acid]] to precipitate as calcium oxalate, thereby avoiding problems such as [[gushing]], [[beer stone]], and oxalate [[haze]].<ref name=bmp5/><ref name=mashing/><ref name=water/><ref name=bsp/><ref name=smart1/><ref name=eumsch/> Oxalic acid removal is also beneficial for individuals with a predisposition for kidney stones.
* '''Fermentation performance''' - Calcium helps to protect [[yeast]] cells against the toxic effects of [[ethanol]], particularly when [[high gravity brewing]].<ref name=gib125/> This can lead to improved [[sugars and dextrins|sugar]] utilization and ethanol production in high gravity wort.<ref name=gib125/> Calcium can also sometimes help with [[yeast]] growth and metabolism in standard gravity wort.<ref name=water/><ref name=hob/><ref name=gib125/><ref>Evans DE, Goldsmith M, Dambergs R, Nischwitz R. [https://www.researchgate.net/profile/David-Evan-Evans/publication/277808631_A_Comprehensive_Revaluation_of_Small-Scale_Congress_Mash_Protocol_Parameters_for_Determining_Extract_and_Fermentability/links/578ebce408aecbca4caad696/A-Comprehensive-Revaluation-of-Small-Scale-Congress-Mash-Protocol-Parameters-for-Determining-Extract-and-Fermentability.pdf A comprehensive revaluation of small-scale congress mash protocol parameters for determining extract and fermentability.] ''J Am Soc Brew Chem.'' 2011;69(1):13–27.</ref> In most cases however, higher levels of calcium actually decrease fermentation performance due to the reduced ability of the yeast to uptake [[magnesium]].<ref name=walbir>Walker GM, Birch RM, Chandrasena G, Maynard AI. [https://www.tandfonline.com/doi/abs/10.1094/ASBCJ-54-0013 Magnesium, calcium, and fermentative metabolism in industrial yeasts.] ''J Am Soc Brew Chem.'' 1996;54(1):13–18.</ref>
* '''Improved yeast flocculation''' - Calcium promotes yeast [[flocculation]], leading to improved clarity.<ref name=mashing/><ref name=whiyea>White C. [https://www.jstrack.org/brewing/Yeast_nutrition_article.pdf Yeast nutrients make fermentations better.] White Labs. Accessed 2020.</ref><ref name=water/><ref name=bsp/><ref name=smart1/><ref name=fix/><ref name=hob/>

== How to adjust the calcium level ==
Brewers can increase the calcium level in the brewing water by adding a calcium salt, usually [[calcium chloride]] (CaCl<sub>2</sub>) and/or [[calcium sulfate]] (CaSO<sub>4</sub>). [[Calcium carbonate]] (CaCO<sub>3</sub>) should not be used because it is poorly soluble. [[Calcium hydroxide]] (lime) is another potential source of calcium , and is also not recommended. See [[Water]] for our guide to adjusting water minerals and mash pH.

The easiest way to decrease calcium in brewing water (if the level is excessive) is to purify it with a [[RO systems|reverse osmosis system]]. Another option is boiling the water, which can lower the calcium level if [[bicarbonate]] is also present. However, the amount removed by boiling is variable, so this is not recommended.<ref name=comrie/>

== See also ==
* [[Water]] - Expert guide to adjusting water minerals
* [[Brewing pH]] - Discussion of pH throughout the brewing process, including the benefits of pH control by adjusting calcium.
* [[Calcium chloride]] - Brewing salt
* [[Calcium sulfate]] - Brewing salt

== References ==
[[Category:Brewing chemistry]]
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|title=Calcium in brewing: sources, effects, and recommended level
|description=Calcium is one of the most important components of brewing water due to its beneficial effects on mashing enzymes, pH control, and clarification. Depending on the source water minerals, brewers may need to add calcium chloride or calcium sulfate to achieve the desired level of 50 to 150 mg/L.
|image=Calcium-periodic-symbol.png
|image_alt=Calcium periodic table emblem
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