As a chef I always pay attention to these kinds of reports – food safety is a matter taken very seriously in the catering profession these days, and rightly so. At work, we’re required by Environmental Health Officers (EHO) and the Food Standards Agency (FSA) to undergo regular refresher courses in food safety, because in a busy job it’s all too easy to become complacent, and information is continually being updated in light of new developments. Lethal outbreaks of food-poisoning/food-borne illness are relatively rare, but lower-level sickness is very common and can have legal repercussions for catering establishments and is costly in terms of employee sick leave, in addition to the personal pain and inconvenience of being ill. A large body of scientific and statistical data is available to the professional caterer; along with rules and recommendations for best-practice, and though the risks for the home cook are exponentially less – due to the relatively small output – the general principles are much the same and there’s much that can be learned from the professional model in terms of minimizing food safety risks.
Whilst viruses and the physical contamination of food with chemicals – cleaning products, primarily – or foreign bodies – packaging debris, dirt, broken fingernails, glass splinters etc. – also present issues, most incidences of food-related health-risk are bacterial so that’s mostly what I’ll be focusing on here. The Clostridium Perfringens bacteria implicated in the above story is one of the most prevalent causes of food-related illness, along with Campylobacter Jejuni and Salmonella bacteria. So today’s post consists of a – hopefully, helpful – summary of what I’ve learned over my years of cooking professionally: simple techniques and strategies to ensure safe and happy eating, and what to do in the event things go wrong.
Storage – store raw and cooked items seperately in the refrigerator – ideally keeping the latter on shelves above the former, and definitely in separate containers – to minimise the risk of cross contamination. Some fridges/freezers feature a temperature readout but they’re not always that accurate so it’s worth investing in a food-probe thermometer to check that your appliances are working correctly. Ideally fridges should maintain a temperature of 5ºc or below and freezers -18ºc, and no higher than 8ºc or -12ºc. Even in a fridge, storing food too long will increase poisoning risks (see Use by/Best before – below) and the proliferation of spoilage organisms will quickly rob food of flavour and nutritional value: this is especially true of perishable foods such as fresh fish, poultry and berries.
Washing and cleaning – clean your hands and equipment – knives, chopping boards etc – regularly during food prep, especially in between preparing raw and cooked food. Look for cleaning products – hand wash, hard-surface cleaners, washing-up liquid – that are antibacterial but also food-safe (chlorine bleaches such as Domestos will taint food with an unpleasant odour and taste, in addition to being toxic and irritant).
Danger Zone – In catering we talk about the ‘Danger Zone’ to describe temperatures between 5ºc and 63ºc, this being the range within which bacteria can reproduce most quickly to dangerous levels. No food should be allowed to remain between these temperatures for more than 90 mins, and ideally ought to be kept out of it altogether. Serve cold food straight from the fridge and hot food straight from the stove/oven to minimize risk. Soups, gravies and other sauces can be a potential route of transmission and should be brought to a boil quickly and stirred regularly to ensure heat is evenly-distributed. Microwaves are notorious for heating unevenly, and cool spots in an otherwise hot sauce can allow bacteria to reproduce to dangerous levels. Some bacteria (including the Clostridium implicated in the story above) form spores if heating takes place too slowly, allowing them to survive even boiling thereafter. Egg-based sauces such as Creme Anglaise, Sabayon, Hollandaise and Mayonnaise which are cooked lightly or not at all, and are served warm or at room temperature rather than hot, should not be kept more than 90 mins and discarded thereafter.
High Risk. High-risk foods are those which are ‘ready to eat’ – cooked meats, pates, egg dishes, cheeses (especially unpasteurised ones), sushi/sashimi/tartares, jellies, prepared salads – which won’t be subject to any further bacteria-killing processes (e.g. cooking) prior to service. These dishes require especial care, and leaving them out for extended periods at room temp is a big no-no. After 90 minutes out of the fridge they ought to be binned. As a rule of thumb, any dish which is protein-rich and moist can be considered high-risk. Raw food is only generally high-risk if it is to be consumed raw – so raw meat, poultry and fish, if correctly stored, cooked and served ought not to present a problem. What constitutes correctly-cooked? On the basis of staying out of the Danger Zone (above) we ought to be cooking all of our meat to at least 63ºc all the way thru; but if you’re a lover of rare beef, lamb, tuna or salmon then that’s clearly not an option. In those cases, the important thing is that prime cuts are seared on the outside to eliminate bacteria. Reconstituted meats such as burgers and sausages can be risky if served rare, though; since bacteria are present throughout the meat not just the outside. Undercooked meat products were a major source of the potentially lethal Escherichia coli 157 bacteria strain, nicknamed ‘Barbecue sickness’ in the States. Poultry and pork ought to be cooked until the juices run clear, and a core temperature of 70ºc is recommended; unlike red meat and non-white fish, these meats are pretty unpalatable when undercooked anyway. Use your food-probe thermometer in the thickest part of the meat to check the core temperature (and don’t forget to clean it between uses).
Use-by/best before labels – millions of tonnes of food are needlessly thrown away every year, and especially in the current economic climate consumers may well be feeling under pressure to cut down on wastage. Food date labelling errs, quite sensibly, on the side of caution but before you think about eating that week-old curry in the back of the fridge, take note: the distinction between use by and best before is worth knowing and understanding: the former applies to foods that are high-risk and/or perishable and dates ought to be adhered to rigidly to reduce the likelihood of illness; the latter, as its name suggests, indicates that the quality – flavour, texture etc… – will deteriorate after the date shown but safety isn’t generally a big concern as the foods thus labelled aren’t high risk.
Precautions – avoid goods with damaged packaging or which appear to have been incorrectly-stored. I’ve complained to my local Co-op more than once about price-reduced high-risk items – fresh fish and meat, pre-packed sandwiches, semi-rotten fruit – left unrefrigerated on the counter. This is bad practice and what you save in pennies you may end up paying for in illness. When preparing food, cover any cuts/burns with a sticking plaster, tie up long hair and avoid smoking, scratching and picking your nose (or anything else).
Illness – if you’re suffering from any kind of diarrhoea or vomiting illness it’s better to give the kitchen a wide berth: that’s not always a practical option for home cooks, of course; especially parents with kids to feed. Taking extra care with hand-washing and cleaning of equipment will help to minimize risk, however. If you work in a catering or healthcare environment then you don’t need me to tell you to stay home: your employer will already have the correct procedures in place.
Symptoms – symptoms common to most types of food-related illness and the ones to watch out for, include abdominal pain, nausea, vomiting and diarrhoea, though the exact combination of those and other symptoms can be peculiar to particular types – Campylobacter, for example primarily causes diarrhoea, with fever, disturbed-vision, bloody-diarrhoea, and appendicitis-mimicking abdominal pain variously-present in severe cases. Food-poisoning-like symptoms can also be characteristic of viral infections including Norovirus; whilst the food-borne Clostridium Botulinum bacteria rarely affects the gastrointestinal tract at all: it’s primary symptom is muscular paralysis (Botulism). If in doubt consult a doctor, and any gastrointestinal illness that persists for more than 48 hours ought to be investigated further.
Treatment – most gastrointestinal problems pose more of an inconvenience than a serious threat to health, but can nevertheless be unpleasant. Diarrhoea and vomiting can quickly lead to dehydration, so it’s important to maintain fluid intake, even if you don’t feel like eating. Rehydration sachets can be bought from your pharmacy, but a good home-made alternative is a teaspoon each of salt and sugar dissolved in a glass of lukewarm water. Ginger and peppermint infusions are effective in combating nausea and settling the stomach, as are flat soda pop and Milk of Magnesia. If you can manage food, bland, dry snacks such as unbuttered toast and water biscuits are less likely to upset a delicate stomach, and clear soup. Rest is important, too – though as mentioned above, if symptoms persist or worsen then don’t hesitate to consult your GP – and though it’s better to let minor infections run their course – diarrhoea and vomiting are the body’s natural mode of ejecting pathogenic bacteria and the toxins they excrete, from the system – if you must leave the house, to see aforementioned GP for example, the anti-diarrhoea medicines such as Loperamide (Imodium/Maalox) can provide short-term symptomatic relief.
And speaking of relief, I think I need some respite from all this ‘heavy shit’ so I’ll leave the last word to Mssrs Freese, Muggerud and Reyes: here’s hoping your next weekend roast doesn’t signify a ‘Black Sunday’ in your cooking career…