GreaseShield vs Goslyn: Battle of the GRUs

Just a few years ago, only a small minority of people had heard of FOGs, fatbergs and grease traps let alone more specialist terms such as grease removal units (or GRU’s). Now, the topic dominates the headlines with the term ‘fatberg’ even being added to the dictionary. The public, both on a domestic and commercial level are now greatly aware of the masses congealing in the public sewer systems on a global scale, the causes and how we can collectively combat the problem.
Although grease traps offer a rudimentary solution for separating fats, oils and grease from wastewater before being deposited into the main drainage network, GRU’s or automatic grease traps offer a more sophisticated solution.
Here we set the two leading suppliers of GRU’s head to head to determine which is the best grease management solution for your business.


Based in Northern Ireland, Grease Shield specialise in the production of automatic grease traps available in a full range of sizes to accommodate different water flow rates. The all-in-one system is compliant with water regulations and has earned a number of notable awards.

Effectively separating FOG into a separate self-contained cassette rather than just trapping it in the main tank, undiluted fats, oils and grease can be quickly and easily removed ready for disposal. Whether you have arranged for collection by an approved waste contractor or wish to dispatch product to conversion plants that deal with renewable energy sources, the whole separation and recovery process is simple and efficient.

The design eliminates the need to access the interior of the device for easy, mess-free maintenance and as cleaning can be carried out in-house, you can reduce the costs incurred for the regular cleaning or pumping required with manual or passive traps.

One of the pitfalls of a standard grease trap is that some people have noted a distinct odour emanating from the trap. This is often down to solid matter remaining in the trap, slowly breaking down and decomposing, emitting a strong stench. No need to worry about that with Grease Shield! Grease Shield benefits from a solids filter which ensures that any food debris is collected and can be disposed of on a daily basis. This process means that foul smells often associated with other manual grease traps are eliminated.

Grease Shield automatic grease traps require a mains power supply used to operate a low maintenance FOG roller. The roller attracts FOG and repels water for effective separation. An automatic scraper takes care of the roller for you with minimal user input required. These systems also benefit from a recirculation process which sees greywater being redistributed back through the GRU to help clean the interior and increase the efficiency of FOG removal.

Goslyn / GreaseMaster

The Goslyn brand originated in the USA yet has become a global powerhouse synonymous with expert grease management and removal systems. Counting a number of major, worldwide brands as clients including McDonalds, KFC and Taco Bell, their automatic grease traps can deal with a range of water flow rates.

Known in the UK as the GreaseMaster, the unit is compact and easy to install. Goslyn/GreaseMaster interceptors are extremely versatile and can be retro-fitted with almost all equipment that comes into contact with FOG. A highly efficient and cost-effective method of separating FOG from wastewater, it’s easy to see why this brand is recognised as a leader in the field.

Featuring a solids filter, food debris as small as 2mm is removed from wastewater and held in an easy to access area for quick removal and disposal. Any finer particles which make it through the filter can be removed by using the self-closing silt or ‘flush’ valve. This only needs to be activated for around 5-10 seconds per day to effectively clean the system. As with the GreaseShield unit, the solids are removed, meaning there is no smell or odour created – a common problem in manual grease trap counterparts.

The Goslyn system has an on-board heater which requires a small power supply. The unit utilises hydrostatic pressure at 40°C to maintain FOG in its liquid state. This combination of heat and pressure facilitates the effective separation of fats, oils and grease from wastewater with as much as 99.6% of FOG being pushed through the oil discharge valve into a separate collection chamber for easy disposal. The collected FOG is ready to be disposed of by a licensed waste contractor or sent directly for bio-diesel conversion.

Unlike the Grease Shield’s automatic roller and plastic scraper that will periodically need replacing throughout the lifespan of the unit, a cost that may be covered under warranty in the first year, however, will be at your own cost after 12 months, Goslyn GRU’s don’t use any moving parts which could potentially breakdown. The only issue may come from the heater however with a massive 10-year limited warranty you’ll be covered in the highly unlikely event of a problem arising.

The performance of the Goslyn / GreaseMaster GRU exceeds industry standards and guarantees the device always operates at peak efficiency. The resulting ‘clean’ greywater flows naturally through to the public sewer system, reducing the strain and demand on water treatment and processing plants and helping to combat those dreaded fatbergs.

Comparing the GreaseShield & Goslyn at a Glance

  GreaseShield Goslyn / GreaseMaster
Average Price (ex-VAT)  £3,000 £2,500
Solids Filter  Plastic Metal
Separate FOG Container 
No Moving Parts 
Power  Requires Power Supply Requires Power Supply
No Chemicals 
Cleaning  Empty/Clean Filter & Cassette Daily Empty/Clean Filter & Cassette Daily
Warranty  12 Months 120 Months


Our Verdict

Both Grease Shield and Goslyn / GreaseMaster are undisputedly leaders in the field, both proving effective and efficient at dealing with FOG separation and grease management. With minimal maintenance and quick daily cleaning that can be carried out in-house, there’s none of the expense associated with manual pumping out of other grease traps and certainly none of the inconvenience of having to shut-down the kitchen for cleaning purposes.

Overall, both the Grease Shield and Goslyn / GreaseMaster are much more effective than a passive grease trap but the bottom line is that the Goslyn / GreaseMaster has more plus points. Offering greater overall value for money, eliminating potentially troublesome moving parts and including a longer warranty, the Goslyn / GreaseMaster, for us, just pips GreaseShield to the post.

Get in touch and tell us what you think.