The brewery industry is notorious for generating large volumes of wastewater, which presents a myriad of challenges from both environmental and economic perspectives. Traditional treatment processes often fall short in efficiently managing this wastewater, leading to environmental degradation and regulatory pressures. However, the incorporation of microalgae in wastewater treatment systems emerges as a potent alternative, effectively reducing pollutants while fostering biomass generation that can be repurposed for various applications.

Microalgae possess distinct advantages due to their rapid growth rates and high nutrient uptake capabilities. They assimilate nitrogen and phosphorus from the wastewater, significantly reducing the levels of these nutrients that contribute to eutrophication in aquatic ecosystems. The review meticulously outlines how microalgae can thrive in wastewater environments, showcasing their resilience and adaptability. This natural process not only cleanses the water but also facilitates the creation of valuable biomass that can serve numerous industries, such as biofuels, animal feed, and cosmetics.

The comprehensive investigation covered in the review highlights various strains of microalgae that have proved effective in wastewater treatment. Strains such as Chlorella and Scenedesmus are detailed, illustrating their biochemical pathways and robustness in diverse environmental conditions. This scientific exploration underscores the importance of selecting suitable microalgae species tailored to specific wastewater compositions, emphasizing that the operational success of these bioprocesses hinges on a nuanced understanding of microbial dynamics and nutrient profiles.

Moreover, the review addresses the economic viability of implementing microalgae-based systems. While initial investment costs may raise concerns for some breweries, the authors argue that the long-term benefits far outweigh the expense. The ability to convert wastewater into riches through biomass valorization not only aids in resource recovery but also leads to potential cost savings in waste management and environmental compliance. With strategic planning and collaboration across sectors, the brewing industry can transition toward a circular economy, minimizing waste and maximizing resource efficiency.

Environmental regulations are tightening globally, prompting industries to adopt sustainable practices. The brewing sector is particularly impacted, as stakeholders seek solutions that not only comply with environmental standards but also enhance their corporate social responsibility profiles. Microalgae technology aligns seamlessly with these goals, offering a pathway toward a more sustainable future. The systematic review serves as a critical resource for breweries looking to innovate and adapt amid these environmental pressures.

In addition to reducing pollution and generating biomass, microalgae cultivation can contribute to carbon sequestration efforts. The CO2 naturally produced during fermentation processes can be channeled into algal cultivation systems, enhancing growth rates while simultaneously mitigating greenhouse gas emissions. This symbiotic relationship between wastewater treatment and carbon management presents a holistic approach to addressing climate change while fostering sustainable industrial practices.

Additionally, the review reveals the potential for microalgae biomass to be processed into biofuels, a pressing need as the world shifts away from fossil fuel dependency. By leveraging brewery wastewater as a nutrient source, microalgae can be transformed into biodiesel and bioethanol, providing breweries with a renewable energy source. This synergy between waste, energy, and resource recovery exemplifies innovative circular economy principles that resonate in the current climate of sustainability.

As breweries explore the implications of adopting microalgae systems, the importance of interdisciplinary research and collaboration is highlighted. Engineers, biologists, and environmental scientists must work together to optimize these systems for maximum efficiency and effectiveness. The integration of technological advancements, such as photobioreactors and bioreactors designed for microalgae cultivation, represents a leap forward in harnessing nature’s capabilities for industrial applications, ultimately benefiting both producers and the planet.

In summary, the systematic review showcases the multifaceted benefits of microalgae in brewery wastewater treatment and biomass valorization. As industries increasingly transition towards sustainable operations, adopting such technologies can foster substantial ecological benefits while ensuring operational efficiency. The future of the brewing industry may very well depend on innovations that align with sustainability, and microalgae offer a promising solution that embodies this paradigm shift.

The culmination of this research lays the groundwork for further studies that can expand on the economic models and technological enhancements required to scale these solutions across the brewing industry. Understanding the complexities of microalgal systems and their performance in various wastewater contexts will be crucial to unlocking their full potential. As breweries seek practical and innovative solutions to their waste management dilemmas, engaging with scientific findings such as these will illuminate the path forward.

In conclusion, the brewing industry stands at the forefront of a sustainability revolution, with microalgae positioned as a cornerstone of innovative wastewater management and resource recovery strategies. The diligent work of researchers like de Souza Silva and colleagues not only propels this agenda forward but also ignites a wider conversation about the role of natural processes in industrial applications. By embracing these cutting-edge approaches, the brewing sector can continue to thrive while playing a pivotal role in the transition towards ecological stewardship.

Subject of Research: The role of microalgae in brewery wastewater treatment and biomass valorization.

Article Title: Microalgae for brewery wastewater treatment and biomass valorization: a systematic review.

Article References:

de Souza Silva, P.H.B., Esposti, G.D., Ndiaye, N.C.G. et al. Microalgae for brewery wastewater treatment and biomass valorization: a systematic review. Environ Sci Pollut Res (2025). https://doi.org/10.1007/s11356-025-37057-0

Image Credits: AI Generated

DOI: 10.1007/s11356-025-37057-0

Keywords: Microalgae, brewery wastewater, biomass valorization, sustainability, circular economy, wastewater treatment.

Schubert, a visiting postdoctoral scientist from the esteemed Research Institute for Raw Materials and Beverage Analysis (VLB) in Berlin, partnered with Lafontaine, an assistant professor of food chemistry at the University of Arkansas’s Dale Bumpers College of Agricultural, Food and Life Sciences, to conduct meticulous studies delving into rice’s molecular and fermentable properties. Their research illuminates how integrating rice into brewing not only influences flavor complexity but also enhances the extract yield—the measure of fermentable sugars derived during the mashing process—resulting in economic and sensory advantages.

A driving factor behind this inquiry is the critical distinction between rice cultivars bred for traditional culinary purposes versus those optimally suited for brewing applications. Contemporary breeding programs, like those at the USDA, aim to maximize head rice yield to improve whole kernel recovery for food markets, while international efforts focus on developing low-glycemic varieties with higher amylose content and elevated gelatinization temperatures. However, these characteristics run counter to what brewers need for optimal starch conversion and fermentability, prompting LaFontaine’s call for intentional sourcing and collaboration between brewers and rice breeders to maintain access to rice varieties aligned with brewing performance.

The cultural context of this innovation is equally significant. Long-standing European traditions, particularly the German Reinheitsgebot, or “Beer Purity Law” of 1516, rigidly restricted beer ingredients to water, hops, and malted barley, leaving little room for adjunct experimentation like rice. This has fostered a cultural bias against adjuncts, often dismissing rice as a bland filler or worryingly inferior ingredient. Yet, the U.S. brewing landscape offers a more flexible regulatory environment, facilitating exploration into the nuanced functional and sensory benefits rice can bring, including subtle alterations to flavor profiles and fermentation behavior.

Schubert and Lafontaine’s first study takes aim at crafting nonalcoholic beer—a segment ripe with growth potential given increasing consumer health consciousness and regulatory advisories against alcohol consumption. They employed Saccharomycodes ludwigii, a non-Saccharomyces yeast strain incapable of fermenting maltose, to carefully control alcohol production, ensuring the final product contains less than 0.5% alcohol by volume as per U.S. standards. Within this framework, they investigated how incorporating milled rice affected fermentation dynamics, flavor development, and shelf stability, with rice’s lower natural aldehyde content playing a pivotal role in reducing off-flavors common in nonalcoholic beers.

Results from sensory panels conducted both in Arkansas and Germany revealed intriguing regional taste preferences. Arkansas tasters favored formulations with 30% rice and 70% malted barley, appreciating the balance of traditional malt character and rice-enhanced notes. Conversely, German participants leaned towards malt-dominant blends, highlighting cultural palate differences. At the heart of these flavor distinctions were chemical components such as 3-methyl-1-butanol, a higher alcohol molecule linked to positive mouthfeel and creaminess, which increased with higher rice content without pushing alcohol levels beyond legal limits. This not only refines the sensory profile but also accelerates fermentation thanks to rice’s abundance of simple sugars like glucose and fructose.

Complementing this sensory investigation, a second study spearheaded by food science master’s candidate Matthew Aitkens scrutinized 74 rice cultivars to assess their extract potential during brewing. They found significant variation among cultivars in terms of fermentable sugar release, with lower amylose content correlating with higher extract yields. Interestingly, varieties that cracked more easily during milling facilitated improved starch accessibility, underscoring the importance of physical grain properties alongside chemical composition. These insights offer brewers a roadmap to select rice types that maximize brew house efficiency and cost-effectiveness.

Addressing a common technical misconception, Lafontaine notes that not all rice varieties possess high gelatinization temperatures, which refer to the heat required to break down starch granules for fermentation. Certain rice cultivars display gelatinization points below 65°C (149°F), potentially lowering energy consumption during mashing and making rice more viable for craft brewers mindful of sustainability and production costs. This revelation revolutionizes the concept of rice as a rigid adjunct, instead positioning it as a dynamic ingredient capable of enhancing brewing innovation.

The practical implications of substituting rice in brewing extend beyond flavor and efficiency. Reduced raw material needs from higher extract yields mean less waste, a leaner carbon footprint, and more sustainable production processes. Given Arkansas’s status as the top rice producer in the United States—responsible for approximately 50% of national rice output—this research dovetails with economic incentives embedded in House Bill 1491, which supports the integration of Arkansas-grown rice into beverage manufacturing chains, fostering regional agricultural and industrial synergy.

Beyond technical achievements, the pairing of historical brewing tradition with modern innovation embodies a paradigm shift in beverage science. Schubert and Lafontaine’s combined expertise bridges the gap between established European brewing orthodoxy and the dynamic, exploratory ethos prevalent in American craft brewing. Their work highlights how embracing adjunct diversity, especially when informed by targeted cultivar selection and chemical understanding, can push the boundaries of beer production while preserving quality and consumer appeal.

As the global market for nonalcoholic beer expands—with Germany already seeing 5% market share and U.S. figures poised to rise significantly due to shifting consumer health priorities—the studies underscore rice’s untapped potential to meet demands for flavorful, low-alcohol alternatives. The integration of rice not only aligns with health trends but also offers brewers technical levers to control fermentation kinetics, sensory profiles, and product stability proactively.

Through a lens of sustainability, flavor complexity, and production efficiency, Schubert and Lafontaine’s research repositions milled rice from a misunderstood adjunct to a critical innovation enabler. Their work calls on the brewing industry to reevaluate resource sourcing strategies, embrace cultivar-specific brewing practices, and collaborate closely with agricultural breeders to sustain access to optimized rice varieties that enhance overall brewing performance.

In conclusion, the union of food science precision, agronomic insight, and brewing artistry showcased in these studies heralds a new chapter for rice in beer production. The evidence is clear: far from being a mere cheap filler, rice, when judiciously selected and incorporated, can enhance extract yields, improve sensory outcomes, and accelerate fermentation in nonalcoholic beers. This challenges entrenched notions and invites the brewing community worldwide to tap into rice’s latent potential, promoting innovation, efficiency, and sustainability for the future of brewing.

Subject of Research: The role of milled rice in improving extract yield and sensory quality in nonalcoholic beer production.

Article Title: Investigating the Incorporation of Milled Rice in Brewing Non-Alcoholic Beer to Enhance Sensory Quality

News Publication Date: 17 June 2025

Web References:

• Arkansas House Bill 1491: https://arkleg.state.ar.us/Bills/Detail?id=hb1491&ddBienniumSession=2025%2F2025R
• International Rice Research Institute news: https://www.irri.org/news-and-events/news/irri-reveals-scientific-breakthrough-low-and-ultra-low-glycemic-index-rice
• U.S. Surgeon General’s advisory on alcohol and cancer: https://www.hhs.gov/surgeongeneral/reports-and-publications/alcohol-cancer/index.html
• Beer definition by TTB: https://www.ttb.gov/regulated-commodities/beverage-alcohol/beer/beer-and-malt-beverage-definitions
• University of Arkansas Division of Agriculture: https://aaes.uada.edu/

References:

• Schubert, C., Lafontaine, S., & Rettberg, N. (2025). Investigating the Incorporation of Milled Rice in Brewing Non-Alcoholic Beer to Enhance Sensory Quality. International Journal of Food Properties. DOI: 10.1080/10942912.2025.2520907
• Aitkens, M., Lafontaine, S., Schubert, C., et al. (2025). Unveiling Cultivar and Agricultural Factors Influencing Extract Yield from Milled Rice. Journal of the American Society of Brewing Chemists. DOI: 10.1080/03610470.2025.2499768

Image Credits: U of A System Division of Agriculture photo by Paden Johnson

Keywords: Applied sciences and engineering, Food science, Beverages, Alcoholic beverages, Agriculture, Agronomy, Crop science, Crops, Plants, Food crops, Natural resources management, Sustainable agriculture

FAYETTEVILLE, Ark. — A new economics study shows the potential for an ancient process to develop new domestic demand for rice and offset declining exports.

That process is malting, which has been around for millennia but is usually associated with another grain — barley. But rice, which is grown prolifically in Arkansas, can also be malted and used as an additional sugar source in brewing beer.

Published this month in Nature Partner Journal Sustainable Agriculture, a cost-feasibility analysis found that using rice malt instead of milled rice in beer brewing, as performed by large breweries, would decrease the cost of beer production by 2 to 12 percent. Malted rice also reduces crop-growing acreage needs by half or more because it produces more grain per acre than barley while having an equivalent or greater sugar extract potential.

Brewers who currently use rice for brewing typically use milled rice, like what is found on grocery store shelves. Using this form of rice requires extra processing steps compared to malted rice. This study suggests that malting has the potential to decrease time and energy costs and make using rice more feasible for more small-scale craft brewers to make gluten-free beers.

Since rice is cultivated globally, the study noted, it also has the benefit of serving as a viable malting material for tropical and subtropical countries that currently rely on barley imports for brewing. Malting is a process that allows grains to sprout slightly under controlled conditions, resulting in biochemical changes important for beer production.

Closing an export gap

Arkansas grows more rice than any state in the nation, including half of the national long-grain rice. Domestic long-grain rice exports, however, have dipped about 7 percent over the past 15 years. About 43 percent of the long-grain rice grown in the U.S. was exported last year, down from 50 percent in 2010.

“Alternative markets, like malted rice, can backfill that decrease in exports,” said Lanier Nalley, professor and head of the agricultural economics and agribusiness department for the University of Arkansas System Division of Agriculture and the Dale Bumpers College of Agricultural, Food and Life Sciences at the University of Arkansas. “Developing a domestic market for our own rice ultimately could ensure the long-run sustainability of rice production in Arkansas.”

Nalley is a co-author of the malted rice feasibility study with researchers from the Center for Beverage Innovation, including Bumpers College food science graduate student Bernardo P. Guimaraes and Scott Lafontaine, assistant professor in the food science department for Bumpers College and the Arkansas Agricultural Experiment Station, the research arm of the Division of Agriculture.

Guimaraes and Lafontaine published research in 2024 with findings of several long-grain rice varieties that developed enough enzymatic activity to fully convert their starch source into fermentable sugar when malted. The rice malts also had many different and interesting aromas and flavors, Guimaraes said, which he believes can be used as a standalone raw material or in conjunction with barley malt. The results opened the door to take it to the economists.

Lightning in a bottle

“I was surprised,” Nalley said of the feasibility study on malted rice. “When we started this, I thought there’s no way this is going to work. How long have humans been drinking beer, and how long has rice been around? The economist in me thought, well if this would have worked, they would have done it 400 years ago! But I guess it took lightning in a bottle with Scott and Bernardo to put two and two together to figure this out, because this could work.”

Lafontaine said the disconnect between malted rice and beer may be because beer has been viewed through a “Germanic lens,” which has been influenced by the nation’s long-standing purity law that calls for just barley, hops, water and yeast as the only four ingredients allowed in beer.

“But when you look back at some of the ancient beers that are in Asia — they had millet, they had rice — and archaeologists have found evidence of cereal beverages made with rice,” Lafontaine said. “Who knows? Maybe that rice was malted.”

Lafontaine referred to a 2024 study published in Anthropology titled “Identification of 10,000-year-old rice beer at Shangshan in the Lower Yangzi River valley of China.” 

Gluten-free competition

The study also showed that beer made from 100 percent rice malt, which would make it gluten-free, costs about 30 percent more than barley-based beer.

Guimaraes said all-rice malt beers could come with a lower price tag compared to other traditional gluten-free alternatives and without flavor defects.

Gluten-free malts are generally considered “competitive” by brewers if they are no more than two times the cost of traditional barley malt, Guimaraes noted. With gluten-free beer sales seeing annual revenue increases of over 16 percent, this could potentially open a new market for Arkansas rice, he said.

The gluten limit set by the U.S. Food and Drug Administration to be labeled “gluten-free” is 20 parts per million. Therefore, to ensure safety and prevent cross-contamination, “the use of dedicated gluten-free malts, malthouses and breweries is essential,” Guimaraes added.

The cost-feasibility analysis was supported in part by the Foundational Knowledge of Plant Products program, project award No. 13960138, from the U.S. Department of Agriculture’s National Institute of Food and Agriculture.

To learn more about the Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website. Follow us on X at @ArkAgResearch, subscribe to the Food, Farms and Forests podcast and sign up for our monthly newsletter, the Arkansas Agricultural Research Report. To learn more about the Division of Agriculture, visit uada.edu. Follow us on X at @AgInArk. To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit uaex.uada.edu.

About the Division of Agriculture

The University of Arkansas System Division of Agriculture’s mission is to strengthen agriculture, communities, and families by connecting trusted research to the adoption of best practices. Through the Agricultural Experiment Station and the Cooperative Extension Service, the Division of Agriculture conducts research and extension work within the nation’s historic land grant education system.

The Division of Agriculture is one of 20 entities within the University of Arkansas System. It has offices in all 75 counties in Arkansas and faculty on three system campuses.  

Pursuant to 7 CFR § 15.3, the University of Arkansas System Division of Agriculture offers all its Extension and Research programs and services (including employment) without regard to race, color, sex, national origin, religion, age, disability, marital or veteran status, genetic information, sexual preference, pregnancy or any other legally protected status, and is an equal opportunity institution.

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Media Contact: John Lovett
U of A System Division of Agriculture
Arkansas Agricultural Experiment Station
(479) 763-5929
jlovett@uada.edu

Journal

npj Sustainable Agriculture

Funder

National Institute of Food and Agriculture

DOI

10.1038/s44264-025-00060-6