According to European data, for every hectoliter of beer produced, an average of 20 kg of wet spent grain is generated. Globally, the brewing industry produces an estimated 35 to 39 million tons of spent grain annually, of which over 3.4 million tons are generated within the European Union. In Romania, where both beer consumption and the number of microbreweries have increased steadily in recent years, these quantities are far from negligible. Efficient management of spent grain can make the difference between a costly waste stream and a profitable resource.
Although most breweries treat spent grain merely as a low-value animal feed, the reality is that this by-product is rich in proteins, fibers, vitamins and microelements, substances worth recovering. In an economy increasingly driven by sustainability standards, transforming brewer’s spent grain from “waste” into a “resource” can provide a serious competitive advantage.
Brewer’s spent grain – a valuable by-product
For every 100 kg of processed malt, between 110 and 130 kg of wet spent grain are produced, typically containing 80–85% water. In a medium-sized brewery with an annual production of 100,000 hectoliters of beer, this translates into over 2,000 tons of wet spent grain per year – a large volume that is difficult to handle and prone to rapid spoilage.
Because of its high moisture content, wet spent grain must be disposed of or valorized immediately, which limits processing options. However, through a circular approach, this by-product can become both a revenue source and a pillar of sustainability.
Currently, the most common valorization pathways include:
- Animal feed, thanks to its high protein and fiber content;
- Biogas production, via anaerobic fermentation;
- Food industry applications, as a base for high-fiber or protein-enriched products and snacks.
Why dewatering of spent grain is essential
The main challenge with brewer’s spent grain is its high water content, which increases transportation costs and limits processing potential. By performing mechanical dewatering immediately after filtration, breweries can obtain a product with a higher dry matter content, improved stability and easier handling characteristics.
This simple step transforms spent grain into a valuable and marketable ingredient. With Flottweg decanter centrifuges, brewer’s spent grain can be dewatered without any pre-treatment or additional water, reducing moisture from 80–85% down to approximately 60%, effectively doubling the dry solids content (from around 20% to roughly 40%).
The process is fully automated, takes place in a closed system, and involves no product loss or disruption to other brewing operations. The result: a clean, well-separated spent grain with high nutritional value and clear process water that can be redirected to the wastewater treatment system or reused in production.
Economic and operational advantages of the Brewer’s Spent Grain dewatering process
For an industrial-scale brewery, dewatering spent grain with a Flottweg decanter centrifuge delivers measurable benefits:
- Reduced transportation and handling costs – less water means less total mass to transport;
- Extended storage life – dewatered spent grain spoils more slowly, providing greater logistical flexibility;
- Commercialization potential – the product can be sold as animal feed or as a raw material for biogas production;
- Reduced load on the wastewater treatment plant – less process water and fewer nutrients lost in effluent;
- Energy savings – the dewatered product requires significantly less thermal energy for drying if further processed.
In addition, Flottweg equipment offers automatic CIP (Cleaning-In-Place), quiet operation and easy integration with the brewery’s existing SCADA systems. The system can also be tailored to the brewery’s production scale and spent grain characteristics – available both as plug-and-play units for craft breweries and as turnkey solutions for large industrial lines.
A concrete step toward a circular economy in breweries
In a context where European sustainability directives and waste reduction requirements are becoming increasingly stringent, the ability to valorize every by-product stream of the brewing process is set to become a key competitiveness indicator.
Through the Consultech – Flottweg partnership, we provide Romanian breweries with a comprehensive approach that includes:
- Process audit and loss balance analysis;
- Sizing and integration of separation equipment;
- Commissioning, operator training and local service;
- Pilot testing to validate performance before investment.
With efficient dewatering using Flottweg decanters, brewer’s spent grain becomes a valuable, stable and marketable product, delivering both economic and environmental benefits. Thus, every brewery, whether craft or industrial, can transform an inevitable by-product stream into a profitable link in its own circular economy.
If you wish to evaluate the recovery potential of spent grain in your facility, contact us for a process audit and a custom plan aligned with your plant’s capacity and sustainability goals.
