If the odour of your ground beef begins telling tales, proceed with caution.
Getting good value for meat is important, but surely it’s worth slowing down if your ground beef smells like egg?
Conventional wisdom would say, you’ve got to play it ear, or rather by nose (…and of course eye), if you sense something wrong with your meat purchase.
But it is evident in many cases, these methods of detection are insufficient for detecting dangerous levels of bacteria.
It doesn’t always have to do with the use-by-date either.
Take this Trader Joe’s customer for example:
“…I have some ground beef from Trader Joe’s that has 4 days left until the expiration date. I opened it tonight and noticed that it smells sulfuric, a bit like hard-boiled eggs.”
…quoted from the Hip Domestics Blog
The Center for Food Safety and Sustainability at Consumer Reports says,
“There’s no way to tell by looking at a package of meat or smelling it whether it has harmful bacteria or not…you have to be on guard every time.”
With this weight of evidence and advice urging meat consumers to be cautious with their meat purchases, it’s worth taking a closer look at the detail.
The difference with ground beef
Ground beef is a favourite with many a recipe nowadays.
Barbecue season produces demand for hamburger patties, tacos, chilli and many more variations of ground beef recipes.
Grinding then lesser favoured & tougher cuts of beef and mixing it with a little fat, produces the ground mince we know so well.
However, the physical process of mincing beef produces other non-desirable results.
Whilst whole, the cuts of beef had by comparison a lower surface area, or lower exposure to contact.
Increased surface area by grinding meat into smaller pieces, increases exposure to bacteria in particular.
During processing, transit and store this increase exposure increases the health risks to consumers.
Also, the mixing process of combining meats of various sorts during production further multiplies health and safety risk.
Whilst regulatory standards and measures guide processors and vendors to best practice, this doesn’t nullify all risk.
Therefore consumers ought still to be vigilant.
Which bacteria is particularly dangerous in ground beef?
There are a ‘big five’ bad bacteria which health safety standards agencies warn against, namely:
- Shiga-toxin producing Escherichia coli (STECs) E. coli O157:H7
- Campylobacter jejuni
- Listeria monocytogenes
- Staphylococcus aureus
E.Coli in particular in recent years has received the most heightened press coverage with highly publicised outbreaks occurring world wide.
But how does E.Coli operate?
E.Coli works by colonizing intestinal areas of people and exuding toxins which lead to hemorrhages in the leading to more hazardous outcomes.
E.Coli is also quite resilient at both low temperatures and high temperatures.
This leads to the advice that ground beef must be stored at temperatures below 4.4 degrees C and cook ground beef at internal temperatures above 71.1 degrees C, according to USDA safety standards.
Interestingly enough, the bacteria which make gone off (…sour, sulphur, rotten eggs, broken wind, cheese, wet dog or just plain ol’ bad) meat smell bad isn’t the same that causes adverse health conditions.
Ground beef and spoilage
The spoiling or degradation of meat is due to microbial levels of colonization by commonly identified bacteria.
Bacteria thrive in moist warm conditions with biological substrate like sugars etc.
Meat, therefore, is an ideal environment for bacterial growth.
Bacteria occupy the meat, respiring either in the absence or presence of oxygen.
Such bacteria as, E Coli, release a concoction of gaseous and liquid toxic products.
These toxins have many effects, including breaking down the integrity of the meat, changing it’s consistency and appearance as well as odour.
This quick overview by the Food and Agriculture Organisation, provides simple insight into the separate, yet related processes of spoilage and poisoning:
In both cases above, the threshold between what is generally regarded as safe levels of bacterial detection to dangerous levels is breached very suddenly.
A bacterial tipping point like this can occur quite rapidly and often without physical detection.
This graph, produced by Aggie Horticulture below shows how sharply this switch takes place:
The graph shows that at 4.4 degrees C, the condition of meat tissue at a microbial level exponentially deteriorates at about the 1 day mark.
Depending on the present concentration of bacteria at the start, the sudden climb in toxicity can cause meat condition to enter into ‘odour and slime’ territory.
But not necessarily.
So, what good is a sell-by date for judging condition of ground beef?
It isn’t really.
Sell-by dates are general yard sticks implemented by retailers, as governed by legislation.
It’s a means of indicating to consumers that the meat available for purchase has made a timely arrival to the shelf.
This therefore should indicate (…major caveat here…) that it’s fit for consumption.
However, a sell-by date is no real means of gauging the worthiness of retail meat for consumption.
General consumer advice guidelines encourage ground beef to be consumed within 2 days of purchase from store.
Advice for buying ground beef
Inspect the packaging.
Buy only if the packaging feels cold to the touch. If it feels warm reject it and inform retail staff.
Check for leaks.
This will tell you if the integrity of the packaging has been compromised.
Broken packaging is one way in which bacteria colonies are effectively recruited into the meat.
Ensure your ground beef is one of the last items to be put into your basket.
Also, transport ground beef in a cooler on the way home.
What is best practice for storing ground beef at home?
The advice from the food safety agencies regarding storing ground beef at home is simple:
…refrigerate or freeze as soon as possible after purchase.
This inhibits the growth of bacteria, preventing inherent levels from approaching anywhere near dangerous.
The critical maximum storage temperature for ground beef is 4.4 degrees C.
Below this maximum storage temperature ground beef will typically keep well for 1-2 days.
[…remember the graph above depicting threshold levels of bacteria and time taken to reach dangerous levels].
How long will ground beef keep if frozen?
Typically, for best results, ground beef ground should be stored frozen wrapped within several layers of freezer bags.
This way ground beef can be kept indefinitely according to USDA guidelines.
Quality, however, i.e. tenderness and suppleness of meat will deteriorate over time.
It is therefore advised that you consume ground beef which is frozen within 4 months of freezing.
How to thaw ground beef for best results?
The fridge is the most controlled method of thawing out meat.
Sudden temperature increases will increase the potential for bacterial growth.
Keeping ground beef cold whilst defrosting therefore is critical to preventing bacterial growth.
Hence the use of the fridge.
Ideal fridge temperature is 1.6 degrees C.
This is comfortably below the maximum guideline storage temperature for ground beef.
These conditions are best for preventing bacterial growth.
It is possible to defrost ground beef more rapidly with the use of a microwave or submerged within cold water.
However, leaving ground beef at room temperature is not recommended for any longer than 2 hours.
After this time it is estimated that levels of harmful bacteria will reach poisonous levels.
How dangerous is partially cooked ground beef?
Never partially cook ground beef.
If you re-cook or consume partially cooked ground beef, you run the risk of it hazarding health.
Again, the recommended internal temperature for safely cooking ground beef is 71.1 degrees C.
The duration of cooking also must be sustained to effectively kill off harmful bacteria.
The danger of not achieving the target internal temperature of 71.1 degrees C, is that harmful bacteria are not fully staved off by cooking.
This allows the more resistant strains to gather strength and produce enough toxin within the meat to be harmful if consumed even after further cooking.
But what about the color of ground beef? What does that tell you?
The ‘healthy’ red colour of ground beef at the shop is due to the oxygenation of oxy-haemoglobin in the tissue.
However, freshly cut meat as seen as the abattoir or freshly butchered is more blue-y or purple in shade.
Interior of meat when freshly prepared is more grey in colour which signifies lack of oxygen to internal areas.
However, if you received meat as a consumer (further down the supply chain), which is grey in colour, this could be spoilage.
Conclusion to…’If ground beef smells like eggy sulphur, should I still cook?’
If your ground beef smell like eggs or sulphur, it has already begun to spoil.
This means that harmful bacteria have already begun to multiply within it.
Best practice would recommend replacing it, rather than consuming it.
Do you have any notable retail experience with ground beef?
Are you professionally trained, i.e. a chef or cook with expertise to add?
Feel free to comment below.