Mashing studies using Tiger Nut (Cyperus esculentus) flour as adjunct in brewing

Brewing industry worldwide is constantly looking for ways to reduce production costs and improve product quality. This has been done over the years using cereal extracts known as adjuncts. An increasing world population requires increased production of grains for consumption which necessitates research into non-grain sources as adjuncts for brewing. Tiger nut (Cyperus esculentus) flours were utilized in this work to investigate its suitability for use as brewing adjunct in conjunction with malted barley. Proximate analysis and mashing process were carried out on the samples and the resulting wort analysed. Tiger nut flour was defatted using Soxhlet extraction method to reduce the fat content to a level tolerable for brewing, 18.74% for the normal tiger nut (NTN) flour and 1.30% for the defatted tiger nut (DTN) flour which compared with the barley malt with lipid content of 2.58%. The normal and defatted tiger nut flours had total carbohydrate content of 50.61 and 55.83% respectively while barley malt was 79.44%. The barley malt also had a diastatic power of 119 ᵒL. Various worts were obtained by an infusion mashing system for the all-barley malt mash and double mashing system for the malt and adjunct mashes (NTN and DTN flours) using the gelatinization temperature of 66 ᵒC for the tiger nuts. Tiger nut flours were mashed with barley malt in combinations of 50/50 and 30/70 to produce wort. All the worts obtained tested negative for starch using the Iodine test. Extract values for the 70/30 and 50/50 barley malt-NTN combinations were 13.05 ᵒP and 13.8 ᵒP respectively. The 70/30 barley malt-DTN and 50/50 DTN combinations also gave extract values of 11.60 ᵒP and 12.94 ᵒP respectively. The wort from the 50/50 DTN combination compared most favorably to the wort obtained from the all-barley-malt mash. This indicates that there is potential for the use of tiger nut flours as adjunct in brewing although there is a need for further studies on more efficient methods of reducing lipid content.