CESA, the Catering Equipment Suppliers' Association, answers your kitchen equipment queries.
Q We're having problems with blocked drains. We recently fitted a new dishwasher - is this the cause?
A Blocked drains can be caused by fats that wash off dirty plates, as well as fat spilled on the floor or by bad kitchen practice. A key kitchen discipline is grease management, and any excess fats, oils or grease (FOGs) should be deposited into a sealable container for collection.
But no matter how well the plates are scraped, some FOGs will inevitably escape down the drains during pre-rinsing or washing. Blockages can be avoided by fitting a grease trap or fat-separation unit to the water outflow system, and/or installing a biological method of treating FOGs, which is called bioremediation.
A grease trap works by slowing down the flow of warm or hot greasy water coming out of a dishwasher and allowing it to cool. As the water cools, the grease and oil separate and float to the top of the grease trap. The cooler water, containing less grease, continues to flow down the pipe to the sewer. The grease is trapped by baffles, preventing it from flowing out of the trap. The baffles should be regularly removed for cleaning, at which point the grease is disposed of.
Most importantly, a grease trap has to be sited sufficiently far away from the dishwasher to allow the emulsified fat to cool and separate out from the water. Waste water from dishwashers, combi-ovens and potwash areas can range from 40°C to 95°C. If the temperature is too high and the grease trap too close, FOGs remain in solution and can be flushed through traps, causing problems in the drainage system when they eventually coagulate. Talk to your supplier or maker to find out the best way to fit a grease trap at your site.
In bioremediation, the drains are regularly dosed - usually overnight - with a multi-strain bacterial solution that breaks down FOGs and keeps the drains clear.
There are many different commercial bioremediation fluids on the market, of different properties and strengths. Fatty acids comprise most of what is found in commercial kitchen drains, and they are the most difficult to break down. Some bioremediation systems have a multi-strain capacity to break down fatty acids and the other types of FOGs found in kitchens.
Some operators choose to use bioremediation and grease traps together, as this increases efficiency.
Q What's more energy-efficient, a griddle or a grill?
A Grills and griddles are very common and are often used to cook similar foods. If energy saving is the prime consideration you should specify a griddle - they are usually more energy-efficient than a grill. If you want to minimise energy use, the Carbon Trust suggests a chrome-plated mild-steel griddle as this puts more heat into the food, radiating less into the kitchen. It thus also puts less pressure on your extraction and ventilation systems, saving even more energy.
One of the most cost-effective improvements you can make is to specify a griddle with thermostatic controls, so you can manage its temperature and use only the power you need.
Q I've been recommended wooden chopping boards for food prep - aren't these unhygienic?
A Properly washed and sanitised, wood is a perfectly hygienic cutting surface. Plastic chopping boards began to be recommended in the 1990s, when wood fell out of favour because it was thought - incorrectly - to be unhygienic. However, wood does take a certain amount of looking after and, unlike plastic, can't be put through the dishwasher.
Wood's major advantage in the commercial kitchen is that it is the kindest material to the cutting edge of a knife. Plastic will blunt knives more quickly.
To clean wooden boards, wash them in hot, soapy water and use a sanitising spray. To keep them in good condition, they should be regularly scraped with a steel scraper to remove heavy soil and scuff marks, and oiled to waterproof the wood - any kitchen cooking oil will do.
Energy-saving is a prime consideration in many kitchens
For more advice
Visit www.cesa.org.uk and click on the link "CESA Buying Guides".For energy saving advice click on "CESA Energy Saver".
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