Effect of wheat malt on the concentration of metal ions in wort and brewhouse by-products

Abstract

The ionic composition of brewer's wort depends on the raw materials and processing employed. The macroelement content is usually sufficient for yeast, but some of the microelements (mainly zinc) often need to be supplemented to the wort. Wheat malt is used as an adjunct in the production of beer, replacing up to 60% of barley malt. In this study, the effect of replacing barley malt with wheat malt on the concentration of magnesium, manganese, iron and zinc ions in brewer's wort was investigated. The ionic content of both the raw materials and by-products were analysed. Similar amounts of magnesium ions were found in wheat malt and barley malt, whereas, manganese, zinc and iron were more abundant in the wheat malt. Nevertheless, wheat malt did not cause a significant change in ion concentration in the first wort (except for magnesium; its content decreased). The ionic content in the spent grains increased owing to wheat malt addition; the concentration of ions in the wort decreased after wort boiling (Mn 2+ and Fe) or remained unaffected (Mg 2+ and Zn 2+). It was concluded that the ionic composition of the wort depends mainly on the removal rate of ions from the wort during mash filtration and hot trub separation, rather than on the actual amount of ions in the raw materials.

Sorption isotherms and thermodynamic properties of wheat malt under storage conditions

“…Due to the high costs of barley malt, wheat malt has become an interesting alternative with comparable technological properties due to its high availability in comparison to others cereals such as sorghum, rice, and corn (Poreda, Bijak, Zdaniewicz, Jakubowski, & Makarewicz, 2015). Because of that, malting wheat grains demonstrated to be attractive not only for the brewing sector but also in the production of whisky, biscuits, bread, and probiotic beverages (Agu, Bringhurst, & Brosnan, 2006; Hu, Jin, & Du, 2019; Marti, Cardone, Nicolodi, Quaglia, & Pagani, 2017; Sharma, Mridula, & Gupta, 2014; Wani & Sood, 2014).…”

The Use of Non-Saccharomyces Yeast and Enzymes in Beer Production

“…The principal source of zinc is malt, from which zinc is extracted in the mashing process (De Nicola & Walker 2009). The optimum demand of yeast for zinc oscillates between 0.1-1 mg/L of wort (Poreda et al 2015). Zinc content in the wort produced from barley malt was at the appropriate level (0.63 mg/L) required for the proper performance of yeast.…”

Transition metals in brewing and their role in wort and beer oxidative stability: a review

“…The use of whole hops, rather than pellets or extracts, raises the antioxidative polyphenol content of the wort but also tends to be higher in heavy metals ( 237 ) . With malt, the wort metal content can vary by variety, cultivation, and roast intensity ( 182,185 ) . Similar considerations also apply to spices, herbs, and other additives ( 238 ) .…”

“…Beer has a much lower transition metal content than wort (183), which make the ransfer rates appear low. The explanation for this is that a large fraction of the metals in wort are bound to nitrogenous and polyphenolic compounds and are removed with the hot break and trub during mashing, wort boiling, and in the whirlpool (181,(184)(185)(186). The spent grains, left after lautering or mash filtration, are also a great sink for metals, particularly transition metal ions (187,188).…”