MAIZE ADJUNCT UTILIZATION IN SORGHUM BEER BREWING: EFFECTS ON FERMENTATION PERFORMANCE, PHYSICOCHEMICAL PROPERTIES, AND CONSUMER ACCEPTABILITY

ABSTRACT

The increasing demand for affordable, nutritious, and locally sourced brewing materials has stimulated growing interest in the use of cereal adjuncts in beer production, particularly in developing countries where sorghum remains an important indigenous grain. This study investigated the utilization of maize adjunct in sorghum beer brewing with emphasis on fermentation efficiency, physicochemical characteristics, sensory quality, and overall consumer acceptability. The research was motivated by the need to improve the brewing potential of sorghum-based beverages while reducing dependence on imported barley malt in the brewing industry.

An experimental research design was adopted for the study. Sorghum malt was blended with varying proportions of maize adjunct during wort production and fermentation processes. Standard brewing procedures involving malting, mashing, lautering, boiling, fermentation, conditioning, and packaging were employed. Laboratory analyses were conducted to determine alcohol content, pH, specific gravity, colour, bitterness, viscosity, and microbial stability of the beer samples. Sensory evaluation was also carried out using a panel of assessors to determine taste, aroma, clarity, mouthfeel, and overall acceptability of the products.

The findings revealed that the incorporation of maize adjunct significantly influenced fermentation characteristics and beer quality parameters. Beer samples produced with moderate maize adjunct inclusion demonstrated improved fermentable sugar conversion, acceptable alcohol yield, enhanced clarity, and reduced production costs. The study further established that appropriate maize-sorghum blending ratios improved sensory acceptability without negatively affecting the nutritional and organoleptic qualities of the final product.

The research concluded that maize adjunct can successfully be utilized in sorghum beer brewing as a cost-effective and sustainable alternative ingredient capable of enhancing local beer production. The study therefore recommends increased adoption of locally available cereal adjuncts by small-scale and industrial brewers to promote food security, reduce brewing costs, encourage agricultural commercialization, and strengthen indigenous brewing technologies in Nigeria and other developing economies.

TABLE OF CONTENTS

Title Page

Certification

Approval Page

Dedication

Acknowledgements

Abstract

Table of Contents

List of Tables

List of Figures

CHAPTER ONE: INTRODUCTION

1.1 Background to the Study

1.2 Statement of the Problem

1.3 Aim and Objectives of the Study

1.4 Research Questions

1.5 Research Hypotheses

1.6 Significance of the Study

1.7 Scope of the Study

1.8 Limitations of the Study

1.9 Operational Definition of Terms

CHAPTER TWO: LITERATURE REVIEW

2.1 Concept of Beer Brewing

2.2 Historical Development of Sorghum Beer

2.3 Sorghum as a Brewing Grain

2.4 Maize Adjunct in Brewing Technology

2.5 Malting and Fermentation Processes

2.6 Brewing Enzymes and Starch Conversion

2.7 Physicochemical Properties of Beer

2.8 Sensory Evaluation of Cereal-Based Beverages

2.9 Microbial Activities in Brewing

2.10 Nutritional Composition of Sorghum Beer

2.11 Challenges in Sorghum Beer Production

2.12 Modern Trends in Gluten-Free and Indigenous Beer Production

2.13 Empirical Review

2.14 Theoretical Framework

2.15 Gap in Literature

CHAPTER THREE: MATERIALS AND METHODS

3.1 Research Design

3.2 Study Area

3.3 Sources of Raw Materials

3.4 Experimental Materials and Equipment

3.5 Preparation of Sorghum Malt

3.6 Preparation of Maize Adjunct

3.7 Brewing Procedure

3.8 Fermentation Process

3.9 Physicochemical Analysis

3.10 Sensory Evaluation

3.11 Microbiological Analysis

3.12 Method of Data Analysis

CHAPTER FOUR: RESULTS AND DISCUSSION

4.1 Physicochemical Characteristics of Beer Samples

4.2 Fermentation Performance

4.3 Alcohol Yield and Specific Gravity

4.4 Sensory Evaluation Results

4.5 Microbial Stability of Beer Samples

4.6 Discussion of Findings

CHAPTER FIVE: SUMMARY, CONCLUSION, AND RECOMMENDATIONS

5.1 Summary of Findings

5.2 Conclusion

5.3 Recommendations

5.4 Suggestions for Further Studies

References

Appendices

CHAPTER ONE

INTRODUCTION

1.1 Background to the Study

Beer is one of the oldest and most widely consumed fermented beverages in the world. Traditionally, beer production relies heavily on malted barley as the primary source of fermentable sugars. However, the high cost and limited availability of barley in many tropical countries have encouraged researchers and brewers to explore alternative local grains such as sorghum, millet, maize, rice, and wheat for brewing purposes. Among these cereals, sorghum has emerged as one of the most important substitutes due to its adaptability to tropical climates, drought resistance, nutritional value, and high carbohydrate content.

In many African countries, including Nigeria, sorghum is widely cultivated and utilized in the production of traditional alcoholic beverages such as burukutu, pito, and other indigenous beers. The crop plays a significant role in food security, rural livelihoods, and agro-industrial development. Sorghum-based brewing has gained increased attention because of its economic potential and suitability for gluten-free beer production. According to Taylor and Dewar (2001), sorghum possesses desirable brewing qualities such as starch availability, enzymatic activity, and fermentable extract potential that make it suitable for beer production.

Despite these advantages, sorghum beer production is often associated with certain technological challenges, including low enzymatic activity, reduced fermentable sugar yield, poor foam stability, and variations in flavour characteristics. These limitations have necessitated the incorporation of adjunct materials during brewing processes to improve beer quality and production efficiency. Adjuncts are unmalted cereal or carbohydrate sources added during brewing to supplement malt and influence beer characteristics such as flavour, body, alcohol content, clarity, and colour.

Maize is one of the most commonly used adjuncts in the brewing industry due to its high starch content, availability, affordability, and neutral flavour profile. In industrial brewing, maize adjunct contributes fermentable carbohydrates that enhance alcohol production while reducing brewing costs. The use of maize in sorghum beer brewing may also improve wort fermentability, reduce viscosity, and enhance sensory qualities of the final product.

Globally, increasing consumer preference for gluten-free and locally sourced beverages has stimulated research into alternative brewing grains and indigenous brewing technologies. Gluten intolerance and celiac disease have further increased the demand for sorghum-based beers because sorghum naturally lacks gluten proteins commonly found in barley and wheat. Consequently, sorghum-maize composite brewing systems present significant opportunities for product diversification and innovation in the beverage industry.

Furthermore, the promotion of local cereal utilization in brewing aligns with agricultural development goals aimed at encouraging indigenous crop production, reducing import dependence, and stimulating rural economies. In Nigeria, where maize and sorghum are extensively cultivated, the integration of both cereals in brewing could enhance value addition, create employment opportunities, and support agro-industrial sustainability.

Advancements in brewing science, food technology, and fermentation biotechnology have also made it possible to optimize local grain utilization for commercial beer production. Modern brewing techniques involving controlled fermentation, enzyme supplementation, yeast strain improvement, and quality assurance systems can significantly improve the quality and consistency of sorghum-based beers.

However, despite growing interest in sorghum brewing, there remains inadequate empirical information on the effects of maize adjunct inclusion on fermentation performance, physicochemical properties, and sensory characteristics of sorghum beer in Nigeria. This study therefore seeks to evaluate the utilization of maize adjunct in sorghum beer brewing with the aim of improving product quality, production efficiency, and consumer acceptability.

1.2 Statement of the Problem

The brewing industry in many developing countries continues to face challenges associated with the high cost of imported barley malt, fluctuations in foreign exchange, and limited access to brewing raw materials. These challenges have intensified the search for locally available cereal substitutes capable of supporting sustainable beer production.

Although sorghum has been identified as a suitable alternative brewing grain, its use in beer production is constrained by poor malt quality, low enzyme activity, reduced extract yield, and inconsistent sensory properties. These limitations often result in lower fermentation efficiency and reduced consumer acceptability compared to conventional barley-based beers.

Maize adjunct has been widely used in industrial brewing to improve starch conversion and reduce production costs. However, excessive or poorly optimized adjunct inclusion may negatively affect beer flavour, foam stability, colour, aroma, and nutritional quality. In Nigeria, limited research has adequately examined the appropriate incorporation levels of maize adjunct in sorghum beer brewing and its overall impact on product quality.

Furthermore, the increasing demand for gluten-free and indigenous alcoholic beverages requires scientific evaluation of alternative cereal combinations capable of producing high-quality beer acceptable to consumers. Without sufficient research evidence, local brewers may continue to experience production inefficiencies and inconsistent product quality.

Therefore, this study seeks to investigate the effects of maize adjunct utilization in sorghum beer brewing with emphasis on fermentation characteristics, physicochemical properties, sensory quality, and consumer acceptability.

1.3 Aim and Objectives of the Study

The main aim of this study is to evaluate the utilization of maize adjunct in sorghum beer brewing.

The specific objectives are to:

1. determine the effects of maize adjunct on the fermentation performance of sorghum beer;
2. evaluate the physicochemical properties of sorghum-maize beer blends;
3. assess the sensory characteristics and consumer acceptability of the beer samples;
4. examine the influence of maize adjunct on alcohol yield and microbial stability;
5. determine the most suitable maize-sorghum blending ratio for quality beer production.

1.4 Research Questions

The study seeks to answer the following questions:

1. How does maize adjunct influence fermentation efficiency in sorghum beer brewing?
2. What are the physicochemical properties of beer produced from sorghum and maize blends?
3. Does maize adjunct affect the sensory quality and acceptability of sorghum beer?
4. What impact does maize adjunct have on alcohol content and microbial stability?
5. Which maize-sorghum ratio produces the most acceptable beer quality?

1.5 Research Hypotheses

The following null hypotheses will guide the study:

1. Maize adjunct inclusion has no significant effect on the fermentation performance of sorghum beer.
2. There is no significant difference in the physicochemical properties of beer produced from different sorghum-maize blends.
3. Maize adjunct utilization has no significant influence on the sensory acceptability of sorghum beer.

1.6 Significance of the Study

The findings of this study will be beneficial to brewers, food scientists, agricultural researchers, entrepreneurs, policymakers, and consumers.

The study will provide empirical information on the suitability of maize adjunct in improving sorghum beer production. It will also assist brewing industries in developing cost-effective and high-quality local beer products using indigenous raw materials.

Agricultural stakeholders will benefit from increased demand for maize and sorghum production, thereby promoting local agriculture and rural economic development. The research will further contribute to reducing dependence on imported barley malt and encourage sustainable utilization of locally available cereals.

Additionally, the study will support ongoing efforts toward the production of gluten-free beverages suitable for individuals with gluten intolerance. The findings may also serve as reference material for future researchers in food science, brewing technology, fermentation science, and agro-processing.

1.7 Scope of the Study

This study focuses on the utilization of maize adjunct in sorghum beer brewing. The research covers sorghum malt preparation, maize adjunct incorporation, fermentation processes, physicochemical analysis, sensory evaluation, and microbial assessment of beer samples.

The study is limited to laboratory-scale brewing experiments using selected maize and sorghum varieties commonly available in Nigeria.

1.8 Limitations of the Study

The study may encounter limitations related to laboratory equipment availability, variations in raw material quality, and financial constraints affecting extensive experimental trials. Time limitations and restricted access to advanced brewing facilities may also influence the scope of analysis.

Despite these limitations, adequate measures will be taken to ensure reliability, validity, and accuracy of experimental results.

1.9 Operational Definition of Terms

Adjunct: A supplementary carbohydrate source added during brewing to improve fermentation and beer characteristics.

Beer: An alcoholic beverage produced through fermentation of malted cereals.

Brewing: The process of producing beer through malting, mashing, boiling, fermentation, and conditioning.

Fermentation: The biochemical conversion of sugars into alcohol and carbon dioxide by yeast.

Maize Adjunct: Processed maize material incorporated into brewing formulations as a starch source.

Physicochemical Properties: Physical and chemical characteristics of beer such as pH, alcohol content, colour, and viscosity.

Sorghum Beer: Beer produced wholly or partly from sorghum grains.

References

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Aisien, A. O., & Muts, G. C. (1987). Brewing characteristics of Nigerian sorghum varieties. Brewing and Distilling International, 17(4), 24–29.

Beta, T., Rooney, L. W., & Marovatsanga, L. T. (2000). Effect of chemical treatments on polyphenols and malt quality in sorghum. Journal of Cereal Science, 31(3), 295–302.

Taylor, J. R. N., & Dewar, J. (2001). Developments in sorghum food technologies. Advances in Food and Nutrition Research, 43, 217–264.

Kunze, W. (2014). Technology Brewing and Malting. Berlin: VLB Publishers.

Ogbonna, A. C. (2015). Indigenous cereal utilization in beer production in Nigeria. Nigerian Food Journal, 33(1), 102–110.

Stewart, G. G. (2017). Brewing and distilling yeast strains. Journal of the Institute of Brewing, 123(1), 15–28.