Table of contents
- Brewery Wastewater
- How to dispose of & recycle wastewater
- Common Uses for Spent Grain
- Less Common Uses
- Factors to Consider
- How to manage TRUB waste
- Yeast & hops sludge
- Hops
- Equipment and Processes for Alternative Methods
- Conclusion
Brewery Wastewater
Every brewery, regardless of size, can benefit from implementing side-streaming practices.
This means separating process waste from different stages and diverting it from the main wastewater stream.
This reduces the volume and strength of wastewater, making it easier for treatment plants to handle.
Here’s where breweries can make the biggest impact
- High-Strength Solid Waste: This includes spent grain and yeast. Hauling companies can collect these for various uses like animal feed or composting.
- Liquid Waste & 1st Rinses: These can be captured and diverted for reuse in cleaning or sent for off-site processing.
How to dispose of & recycle wastewater
Different brewing processes contribute varying amounts of organic matter, measured in Biochemical Oxygen Demand (BOD).
Here’s a breakdown:
- Spent Grain (washing & last run): Up to 100,000 mg/L BOD (very high)
- Processes with lower BOD include lauter tun rinsing, mash tun rinsing, boil kettle dewatering, and whirlpool rinsing.
- Fermenter and storage tank rinses have high BOD due to residual yeast and beer.
- Cleaning processes (filtration) can also generate high BOD wastewater.
Common Uses for Spent Grain
Animal Feed
The most common way to reuse spent grain is as animal feed for cows, pigs, chickens, and even insects.
This is because spent grain still contains nutrients and fiber that animals can benefit from.
Composting
Spent grain can be composted to create a nutrient-rich soil amendment.
However, it is important to note that spent grain is high in moisture and nitrogen, so it may require some additional brown materials (like dead leaves or twigs) to balance the compost pile.
Biogas Production
Spent grain can be used to create biogas, which is a renewable energy source. Larger sites may make use of their own anaerobic digestors which converte the material into methane which can be converted into electricity.
Smaller sites will benefit from partnering with an organic waste processing service provider who can collect the material and transport it to a facility for processing.
Less Common Uses
Mushroom Cultivation: Oyster mushrooms and some other types of mushrooms can be grown on spent grain.
Food Production: Spent grain can be used to make a variety of food products, including bread, crackers, dog treats, granola bars, and even plant-based milk alternatives.
Soil Remediation: Spent grain may be helpful in reducing the time it takes to remediate soil contaminated with diesel.
Building Materials: There is some limited exploration into using spent grain in the production of bio-degradable packaging materials, can carriers, and even some building materials.
Water Treatment: One wastewater treatment facility has experimented with using spent grain in place of alum for water treatment.
Brewing: Some home brewers report reusing a small amount of spent grain in a second fermentation to create a low-ABV beverage like ginger ale.
Factors to Consider
Scale: Some of these reuse options may be more feasible for large breweries than for small homebrew operations.
For example, drying spent grain for use as a fuel source or conversion into building materials may not be practical for small breweries due to the cost and logistics involved.
Logistics: Fresh spent grain is very wet and heavy, so transportation costs can be a factor to consider.
How to manage TRUB waste
Trub, that fine sediment leftover from the beer brewing process, needs a responsible disposal plan.
Here’s a breakdown of the various methods breweries use, along with important details:
Hauling by Licensed Services
Ideal for breweries generating large volumes of trub.
Licensed waste disposal companies transport the trub to anaerobic digestion facilities.
In these facilities, the trub breaks down and produces biogas, a renewable energy source used for electricity generation.
This is an environmentally friendly option with minimal brewery involvement.
Composting
Trub is rich in organic matter, making it a valuable composting ingredient.
Breweries can compost trub on-site with other organic materials like spent grain and hops.
Alternatively, some local farmers might accept trub for their compost piles.
Composting helps reduce waste and creates a nutrient-rich soil amendment.
Feeding Livestock
With proper management, trub can be a source of nutrition for some livestock.
Certain dairies accept trub as cattle feed due to its protein and carbohydrate content.
However, it’s crucial to confirm with the farmer beforehand. Different animals have varying digestive systems, and some may not tolerate trub.
Mixing with Spent Grain for Animal Feed
Some farmers might accept a mix of trub and spent grains for animal feed.
This approach combines the nutritional benefits of both materials but requires careful mixing ratios to ensure digestibility.
Consulting with a nutritionist specialising in animal feed is recommended.
Not Recommended
Dumping Down the Drain:
This is a simple yet irresponsible method with significant drawbacks.
Trub can clog drains with its hop particles and yeast sediment.
Furthermore, large amounts of trub can overwhelm municipal wastewater treatment facilities, impacting their functionality.
Additional Considerations
Breweries using conical fermenters can easily collect trub by using the cone’s bottom outlet valve.
For bucket fermenters, racking (siphoning) the beer off the top layer of trub is a common practice.
Pre-treatment before Disposal
Depending on the chosen disposal method, pre-treatment might be necessary.
For example, some composting facilities might require the trub to be dewatered to reduce its moisture content.
Choosing the best trub disposal method depends on factors like brewery size, local regulations, and available resources.
It’s essential to prioritise environmentally friendly and responsible disposal methods while considering the feasibility and cost for your specific situation.
Yeast & hops sludge
Breweries, big and small, generate a significant amount of byproducts, including hops and yeast.
Disposing of these materials responsibly is not only good for the environment, but also helps maintain a positive relationship with your local wastewater treatment plant (WTP).
Communication is Key
Regardless of brewery size, communication with your local WTP is essential.
They can advise you on their specific regulations and may even offer guidance on alternative disposal methods.
Breweries with larger production volumes may have dedicated staff for environmental compliance.
Smaller breweries can designate a point person to stay informed and liaise with the WTP.
Limiting Wastewater
Large-scale breweries
Consider investing in a yeast collection tank with piping that leads to a dedicated holding tank.
This allows for the easy removal of yeast and trub (sediment) by a hauling company for further processing.
Smaller breweries
Use yeast buckets or carboys to collect yeast for reuse or disposal by a specialised waste hauler.
Hops
Both large and small breweries can explore sidestreaming their hops.
This involves diverting spent hops into separate containers (IBC totes) for collection by local farmers who can use them for compost or animal feed.
Equipment and Processes for Alternative Methods
Yeast Repitching: Many breweries, particularly smaller ones, practice yeast repitching. This involves harvesting healthy yeast from a previous batch for reuse in subsequent brews.
This requires proper equipment like yeast separators and sterile storage containers to maintain yeast viability.
Hops and spent grains (another brewery byproduct) can be composted together.
Larger breweries may invest in industrial composting systems, while smaller operations can use dedicated compost bins or partner with local composting facilities.
Regulations and Considerations
Local regulations regarding wastewater disposal can vary significantly. Always consult your WTP for specific guidelines.
Be mindful of the pH and any chemicals used during the brewing process. Some cleaning solutions or pH-adjusting agents may require special disposal procedures.
Track your brewery’s wastewater output. This data can help identify areas for improvement and demonstrate your commitment to responsible waste management.
Conclusion
By adopting these best practices, pubs & breweries of all sizes can reduce their environmental footprint and ensure the smooth operation of their local wastewater treatment systems.
Remember, a little planning and collaboration go a long way in fostering a sustainable brewing operation!
