Author ORCID Identifier:
Date of Graduation
5-2026
Document Type
Dissertation
Degree Name
Doctor of Philosophy in Food Science (PhD)
Degree Level
Graduate
Department
Food Science
Advisor/Mentor
Lafontaine, Scott
Committee Member
Seo, Han-Seok
Second Committee Member
Nalley, Lawton
Third Committee Member
Fernandes, Samuel
Fourth Committee Member
Wang, Ya-Jane
Keywords
Malted Rice; Quality; Economic Viability; Brewery
Abstract
Climate change threatens the global supply of malting barley, creating a need for sustainable, climate-resilient alternative grains for the brewing industries. This dissertation investigated the chemical, sensorial, practical, and economic viability of using rice as a malting material. First, the malting and brewing qualities of 20 rice samples were evaluated. Results indicated malted rice (MR) had good malting and brewing qualities, including adequate levels of free amino nitrogen (FAN), high amyloglucosidase and limit dextrinase activities. Furthermore, pigmented rice varieties displayed a novel reddish-purple wort color. To identify rice cultivars suited for malting and brewing, the relationship between starch chemistry and amylases present in malted rice was analyzed. Gelatinization temperature played a major role in dictating hydrolysis efficiency, with amylose playing a minor role. While high-amylose rice starch required β-amylase for optimal conversion, waxy variety relied on glucoamylase. Additionally, in adjunct mashing, the inclusion of debranching enzymes further increased sugar production. The sensory potential of malted rice was assessed using the top candidates from previous research to make non- and low-alcoholic beers. These beers were produced using a maltose-negative yeast, and MR had a higher fermentability than barley. Non-aromatic varieties yielded cereal-like flavors, whereas pigmented and aromatic varieties produced distinct vanilla, berry, and creamy notes. Regarding industrial feasibility, pilot-scale malting and commercial brewing trials were conducted. Although rice’s distinct characteristics (e.g., morphology, higher germination and gelatinization temperatures) required operational adjustments (e.g., use of exogenous enzymes, dedicated mill), the production and the use of MR proved to be technically viable at scale. Finally, a Monte Carlo simulation was used to measure the agronomic and economic impacts of producing MR. Agronomically, rice yielded up to 2.8 times more extract per hectare than barley, potentially reducing required agricultural land by over 50%. Economically, although MR costed ~17% more than malted barley, MR remained highly competitive against other gluten-free malts. Moreover, replacing milled rice adjunct with MR could reduce production costs for large breweries by eliminating the need for brewing aids (exogenous enzymes/FAN). Ultimately, malted rice presented a sustainable, gluten-free, and economically viable alternative crop for malting that could shield the brewing industry.
Citation
Pontes Guimaraes, B. (2026). Assessment of the Quality, Practicality, and Economic Viability of Malted Rice. Graduate Theses and Dissertations Retrieved from https://scholarworks.uark.edu/etd/6297
