Editing Adjuncts

{{in progress}} [[Category:Brewing ingredients]]
Adjuncts are unmalted cereals and sugars that are used as a replacement (usually in part) for malted barley (or other malted cereals such as wheat, sorghum, oats, etc.).<ref name=hob6>Stewart GG. Adjuncts. In: Stewart GG, Russell I, Anstruther A, eds. [[Library|''Handbook of Brewing.'']] 3rd ed. CRC Press; 2017.</ref>

Barley malt is a relatively expensive ingredient in the brewing process as it is the product of controlled barley germination and kilning (heat drying) that typically takes 6-8 days and consumes substantial amounts of energy and water. As such, many conventional brewing styles (eg Asia and Nth America) use unmalted starch adjuncts such as barley, wheat, maize or rice that are added to the mash at levels up to up to 60% or even >75% (of malt charge) for the Happoshu style in Japan (Brandee et al., 1999; Haywood, 1996).<ref>Evans DE, Li C, Eglinton JK. [https://www.researchgate.net/publication/226691242_The_Properties_and_Genetics_of_Barley_Malt_Starch_Degrading_Enzymes The properties and genetics of barley malt starch degrading enzymes.] In: Zhang G, Li C, eds. [[Library|''Genetics and Improvement of Barley Malt Quality.'']] Springer; 2010:143–189.</ref> These are added not only as a cheap source of extract, but also give brewers control over attenuation, mouth-feel, flavor, foam head retention or are the result of constraints in local availability.

Adjuncts are often referred to as starch-rich cereals other than barley and wheat malt that are used for several reasons (Glatthar, Heinisch, & Senn, 2002). Cost-effectiveness is an important one for breweries, but the use of adjuncts has also a specific impact on the taste of the end product. Adjuncts can be part of a specific beer style as determined by traditions or because the crops are locally grown. While the drinkability is improved when using rice or corn as an adjunct, specific taste profiles or better foam retention are achieved with cereals like barley, wheat, sorghum, rye or oats (Bamforth, 2006). The latter has gained interest for the production of beers for people suffering from Coeliac disease (Kordialik Bogacka, Bogdan, & Diowksz, 2014). Corn or rice will increase extract yield due to their high starch content, while other adjuncts lead to a reduced extract yield, higher turbidity and higher wort viscosity resulting in filtration issues (Kordialik-Bogacka et al., 2014).<ref name=landes>Langenaeken NA, De Schutter DP, Courtin CM. [https://lirias.kuleuven.be/retrieve/575863 Arabinoxylan from non-malted cereals can act as mouthfeel contributor in beer.] ''Carbohydr Polym.'' 2020;239:116257.</ref>

The maltodextrin content, which is defined here as all non-fermentable soluble starch and derivatives, is increased for all adjunct (unmalted barley, oat, rye) beers.<ref name=landes/>

In brewing, an adjunct is a source of extract other than malt. The term most often refers to unmalted cereal [[grain]], such as rice, which can be used in the [[mashing|mash]].<ref name=kunze>Kunze W. Wort production. In: Hendel O, ed. [[Library|''Technology Brewing & Malting.'']] 6th ed. VLB Berlin; 2019:258.</ref><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> The [[enzymes|enzyme]] potential of the [[malt]] is usually sufficient to [[Saccharification|break down]] this additional [[starch]] during mashing. Adjunct grain is generally less expensive than malt, and therefore it's used as part of the grist in 85-90% of beer produced worldwide. However, since the price and availability of malt is typically not a concern for home brewers, the main reason to use unmalted grains is for their special coloring and flavoring characteristics for the creation of innovative beer types.<ref name=esslinger>Meussdoerffer F, Zarnkow M. Starchy raw materials. In: Esslinger HM, ed. [[Library|''Handbook of Brewing: Processes, Technology, Markets.'']] Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA; 2009.</ref> Sometimes adjunct may also be used to describe non-grain sources of fermentable [[sugars]], such as fruit or honey.

Adjuncts will usually be used as less-expensive sources of fermentable extract. In addition, adjuncts can be used to impart elements of beer characteristics and quality such as color, flavor, foam, body, and drinkability. <ref name=bmp2>Stewart G. Adjuncts. In: Bamforth CW, ed. [[Library|''Brewing Materials and Processes: A Practical Approach to Beer Excellence.'']] Academic Press; 2016.</ref>

The term "adjuncts" does not include materials that are peripheral to beer and do not become part of the final malt beverage product such as filter aids, insoluble colloidal stabilization agents, brewing water treatment materials, consumed yeast nutrients, yeast wash and care materials, and coagulant and flocculents that settle and are filtered out.<ref name=hob10>Ryder DS. Processing aids in brewing. In: Stewart GG, Russell I, Anstruther A, eds. [[Library|''Handbook of Brewing.'']] 3rd ed. CRC Press; 2017.</ref>

There is a limit to the amount of adjunct that can be used to make a wort that will provide enough nutrients for the yeast to produce an acceptable beer and where the yeast remains vital and viable enough to be used again. The limit (for most brewing yeast strains) is around 50% adjunct. At this point, the amount of nitrogenous material, commonly measured as free amino nitrogen, becomes so low that yeast nitrogen is significantly modified,6 leading to flavor changes in the beer.<ref name=hob10/>

When brewing with adjuncts, keep in mind:
* Adjuncts generally do not provide adequate nutrition for the [[yeast]].<ref name=kunze/><ref name=esslinger/> Therefore nutrient supplementation is typically beneficial to ensure a healthy fermentation.
* Adjuncts do not provide enzymes to aid [[Saccharification|starch conversion]]. Therefore adjucts can only constitute up to about 50% of the grist without requiring the addition of exogenous [[enzymes]], depending on the base malt. However 15-20% is generally a safer limit.<ref name=kunze/><ref name=esslinger/>
* Starchy adjuncts must either be pre-gelatinized, or have a [[gelatinization]] temperature lower than the beta-amylase rest. See [[Mashing]].
* Difficulty recirculating or lautering may be caused by using huskless adjuncts in the [[mashing|mash]].
* Adjuncts often contain relatively more glucose than malt. [[Yeast]] fermentation of maltose is repressed by glucose, therefore fermentation patterns of all malt all-malt/adjunct mixtures might differ from each other.<ref name=esslinger/>


Torrification of cereals is a process by which cereal grains are subjected to heat at 260ºC and expanded or "popped" (popcorn process). This process renders the starch pregelatinized and thereby eliminates the brewhouse cooking step.<ref name=hob6/> There are no handling or dust problems associated with the use of torrified cereals. It is possible to blend these torrified products with malt. They can then be ground simultaneously and mashed-in together. However, if they are used and the torrified product is cooked at 71ºC to 77ºC prior to addition to malt, higher yields will result. Torrified cereals lead to increased lauter grain bed depth and to slight runoff penalties. Particle size and mill settings are critical, with large particle size leading to poor yield and with too fine a grind resulting in runoff problems.<ref name=hob6/>

Maize, rice, and sorghum are also available as grits. Grits are small chunks of unprocessed endosperm. Rice grits are generally the by-product of processing of rice for food (the broken bits). Grits need to be cooked to gelatinize their starch granules before being added to a mash. Enzymes are also helpful to start the starch conversion in the cereal cooker or aid it in the mashing vessel. Grits have the same flavor/color properties as their torrefied counterparts (not much).<ref name=smart1>Howe S. Raw materials. In: Smart C, ed. [[Library|''The Craft Brewing Handbook.'']] Woodhead Publishing; 2019.</ref>

The beers produced with grain adjuncts contain less nitrogen, they show a lower final degree of fermentation, better foaming properties, but poorer filterability. The taste stability can leave something to be desired compared to pure malt beers.<ref name=adb>Narziss L, Back W, Gastl M, Zarnkow M. [[Library|''Abriss der Bierbrauerei.'']] 8th ed. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA; 2017.</ref>

The addition of 20% unmalted barley has little effect on the wort soluble protein or free amino nitrogen (FAN) levels of infusion mashes, but when the proportion of barley was raised to 60% both the wort SP and free amino acid levels are strongly depressed. This is partly because the unmalted grain doesn't release protein, and partly due to the presence of endoprotease inhibitors.<ref>Jones BL. [https://www.sciencedirect.com/science/article/abs/pii/S0733521005000743 The endogenous endoprotease inhibitors of barley and malt and their roles in malting and brewing.] ''J Cereal Sci.'' 2005;42(3):271–280.</ref> The same effect occurs with unmalted wheat and maize.

The level of unmalted adjuncts is typically between 20–50%.<ref name=mashing>Evans E. [[Library|''Mashing.'']]  American Society of Brewing Chemists and Master Brewers Association of the Americas; 2021.</ref> Historically, adjuncts were used to decrease beer cost or because they are easier to obtain. In current times, adjuncts are used to dilute protein content when using high-protein malts, such as 6-row. Adjuncts with high gelatinization temperature are typically boiled as a cereal mash (including a rest at 70–75°C) along with some malt (10–33% of the malt bill) or exogenous alpha amylase enzyme. On the other hand, unmalted wheat, rye, and oats can be added directly to the mash; they all have some degree of beta amylase activity.

During the production process of creating cereal adjunct flakes, all enzymes are denatured.<ref name=vanvan>Vanbeneden N, Van Roey T, Willems F, Delvaux F, Delvaux FR. [https://www.sciencedirect.com/science/article/abs/pii/S0308814608003348 Release of phenolic flavor precursors during wort production: Influence of process parameters and grist composition on ferulic acid release during brewing.] ''Food Chem.'' 2008;111(1):83–91.</ref>

Also see [[Grain]].

*Kunz, T., Müller, C., Mato-Gonzales, D., and Methner, F.-J. The influence of unmalted barley on the oxidative stability of wort and beer. J. Inst. Brew. 118:32-39, 2012.
*Haywood R. Brewing adjuncts. Brew. 1996;82:309–311.
*O'Rourke T. Adjuncts and their use in the brewing process. Brew Guard. 1999;128:32–36.
*[https://www.sciencedirect.com/science/article/abs/pii/S0924224416300930 Alternatives to malt in brewing]
*[https://www.mdpi.com/2306-5710/7/1/4 Brewing with Unmalted Cereal Adjuncts: Sensory and Analytical Impacts on Beer Quality]

===Adjunct sugars===
When brewing with added sugar or syrup, it is added to the wort kettle about 10 minutes before [[casting]].<ref name=kunze/> These sugar products do not need pre-treatment. Additional nutrient (or a protein rest) should be considered since the added sugar has no protein (nitrogen).

Liquid adjuncts are usually added to the brew at the wort boiling stage. The major sugars are glucose syrups, cane sugar syrups, and invert syrups. Although these syrups differ in detail, the essential similarity is that they are all largely concentrated fermentable solutions of carbohydrates. The term glucose can be misleading. Although glucose is the commonly used name for dextrose glucose syrups used in brewing, they are solutions of a large range of sugars and will contain, in varying proportions, depending upon the hydrolysis method employed, glucose (dextrose), maltose, maltotriose, maltotetraose, and larger dextrins.26<ref name=hob6>Stewart GG. Adjuncts. In: Stewart GG, Russell I, Anstruther A, eds. [[Library|''Handbook of Brewing.'']] 3rd ed. CRC Press; 2017.</ref>

A small amount of added sugar is not detrimental to beer taste because it is completely fermented.

* Sucrose - Pure cane sugar is perfectly acceptable, but partially purified preparations have been preferred because of their luscious flavors.<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>

Different colors of invert are available and although the darker ones are more highly colored than plain sugar they do not contribute a significant amount of flavor or color when compared to even modestly colored malt.<ref name=smart1>Howe S. Raw materials. In: Smart C, ed. [[Library|''The Craft Brewing Handbook.'']] Woodhead Publishing; 2019.</ref>

Sugars are best used as late as possible in the brewhouse (i.e. at the end of the boil) to avoid losses and color/flavor pick up.<ref name=smart1/>

Fructose accelerates oxidative processes, and therefore it should be added directly before fermentation. This avoids the negative impact during wort boiling.<ref>Kunz T, Brandt NO, Seewald T, Methner FJ. [https://www.researchgate.net/publication/281405909_Carbohydrates_Addition_during_Brewing_-_Effects_on_Oxidative_Processes_and_Formation_of_Specific_Ageing_Compounds Carbohydrates addition during brewing – effects on oxidative processes and formation of specific ageing compounds.] ''BrewingScience.'' 2015;68(7):78–92.</ref>

with other cereals like maize grits or rice. These cereal matrices normally contain fewer minerals than malt and so the metal level is less than of all-malt wort. Adjunct worts are less buffered, so there is a lower pH during fermentation ( Holzman and Piendl, 1976) (Table 34.4).<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>

*https://www.jandonline.org/article/S0002-8223(08)01891-9/fulltext Total Antioxidant Content of Alternatives to Refined Sugar
*https://fdc.nal.usda.gov/fdc-app.html#/food-details/170674/nutrients Turbinado sugar nutrition information

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Fun fact: The ''Reinheitsgebot'' "Purity Law" restricts the use of adjuncts in German beer.

==References==