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Understanding Cooking on Hot Stones

With the introduction of theatre kitchens and live cooking stations, hot stone cooking at the table offers an exciting dining experience. But as it needs special stones heated to extremely high temperatures there are a number of Food Safety and Health & Safety issues that you should be aware of if you’re planning to introduce hot stone cooking.

  • Choosing the right equipment/system is essential to ensure that you satisfy Food Hygiene as well as Health & Safety and Public Liability regulations. Important points to consider:  
  • Make sure you have ovens fit for the purpose of holding the weight of the rocks. The thicker the stone the better they hold their heat so expect each stone to weigh in excess of 2kg. Ovens need to be able to hold 90 – 250kg of stones.
  • The ovens must be well insulated and designed to operate at temperatures up to 460oC with high quality insulation to satisfy energy efficiency and Health & Safety Executive compliance.
  • The stones have to cook the food and maintain its temperature above 63oC for a minimum of 35 minutes. (Food Hygiene regulations state hot food must be heated to at least 63oC.)
  • The size and density of the stone will establish how long it takes to heat and also how long it holds its heat. A minimum rock thickness of 30mm is needed to hold the heat for at least 40 minutes.
  • From a public liability issue ensure your supplier has stones that satisfy sanitisation issues. Minerals and irons like arsenic, lead, mercury and asbestos occur naturally in stones so only use stones certified as food safe. Some manufacturers will supply a complete hot stone cooking system/package comprising oven, rocks, platters, stainless steel trays, implements for handling the superheated stones, training manuals and risk assessments covering staff and customer safety.
  • Extra safety issues:
    •  Stone handling implements should be long handled to avoid operator’s hands entering the extreme temperature of the oven when loading and unloading the stones. They should also be stainless steel to comply with food hygiene regulations.
    • Platters to hold the hot stone on the table should be specially designed to keep the stone in position without sliding or moving. Poorly fitted stones may become loose and fall out. Platters need to be durable, compliant with Food Hygiene Regulations and able to withstand the extreme temperatures of the heated stone.
    • Check that your chosen system is certified for compliance by an independent or government safety or sanitisation body.
  • What to avoid:
    • Don’t use other types of ovens to heat the rocks. Only use ovens capable of holding and heating the stones. For example, a pizza oven may not be strong enough to carry the stones’ weight. Using an unsuitable oven may invalidate any warranties and may also invalidate your insurance.
    • Don’t use stones that have not been tested for sanitisation and are not certified food safe.
    • Don’t use domestic stone cooking appliances as they are not designed for the commercial environment.