Food poisoning can pose a serious health risk and a number of people will be affected at some point during their life. Although it usually only lasts a short while, food poisoning can be severe; taking the lives of around 500 people in the UK each year. Minimising the spread of bacteria in a kitchen is therefore incredibly important, and is something that can be done fairly easily by maintaining a good standard of food handling and general hygiene.
The main thing to remember is that food should be kept out of the ‘danger zone’ wherever possible, that is from 5oC to 63oC, because this is the optimum temperature range for bacterial growth.
When food is being cooked, care should be taken to make sure that all of it is cooked thoroughly. In order to kill most bacteria, food must be heated to 75oC for at least 2 minutes. The centre must reach this temperature otherwise there will be areas of the food that still have many bacteria present.
To reduce the risk of food poisoning as much as possible when cooking food, large joints of meat should be cut into smaller pieces to ensure that they are cooked evenly and thoroughly. Additionally, meals that have a high liquid content, for example stews, casseroles and soups, must be regularly stirred during cooking to make sure that all the contents are heated evenly.
When you want to keep hot food hot for a time before serving, it is safe to do so once the food has been properly cooked and if it is held at a temperature of 63oC or higher. How long it is safe to hot-hold food depends on the food type, but generally this should not be done for a period of longer than 2 hours. On a service counter, food is usually held under heat lamps or in a bain-marie; the food should be stirred regularly to avoid cold-spots when the temperature drops into the danger zone.
To cool food down, a similar principle applies because the danger zone should be passed through as quickly as possible. Subsequently, the ideal aim is for food to be cooled to 5oC or below within 90 minutes and then refrigerated. Importantly, hot food must not be put straight into the refrigerator because it can raise the temperature of the fridge allowing condensation to form and contaminate the food. Instead, food should be covered to protect it from contamination and kept in the coolest part of the preparation area until it is cold enough to put into the fridge.
Another common process in food preparation is thawing. Raw foods must be completely defrosted to enable even and thorough cooking throughout, and no thawed foods should ever be refrozen. To prevent contamination, thawing products should be put in a container and covered, away from other foods.
Johnson