Sous vide is a slow-cooking technique that works at a precise time and temperature. However, home cooks wonder if sous vide is safe mainly because of the use of plastic, vacuum, and low temperature for cooking.
Cooking food sous-vide style is relatively new, so it’s natural for us to feel hesitant about it. The key here is to understand proper food preparation guidelines and apply them during sous vide to ensure safety.
Let’s do this by addressing some of your most common sous vide safety and health concerns with answers based on facts and scientific research.
Is It Safe to Sous Vide Food Items Sealed in Plastic?
Some are worried about sous vide because it involves cooking in a plastic bag. There had been concerns about plastic chemicals leaching into food while cooking for hours on low heat.
Researchers agree that plastics can release harmful chemicals when scratched, used, or washed multiple times. However, this reaction depends on the type of plastic.
Specifically, study shows that polycarbonate products are an unhealthy type of plastic.
These contain bisphenol A (BPA), an endocrine-disrupting chemical that can cause various health issues, like immune dysfunction in children and cardiovascular diseases in adults.
There are also concerns about BPA affecting fetal development in the womb among pregnant women.
Some everyday household sources of polycarbonate are cling wraps, plastic plates, and takeaway containers.
However, food-safe plastic bags for sous vide are not unhealthy plastics. These are polypropylene and polyethylene bags, which do not release toxic substances like BPA.
So, as long as you use the recommended BPA-free bags for sous vide cooking, your food should be fine.
For added safety, here are some best practices when using sous vide plastic bags for cooking:
- Do not reuse sous vide bags when cooking raw meat, fish, eggs, or allergy-causing foods.
- You can reuse resealable bags once for cooking fruits and vegetables.
- Do not use or reuse damaged or leaky plastic bags.
- Choose high-quality, resealable plastic bags from trustworthy brands.
- Consider resealable food-grade silicone bags for sous vide to lessen plastic use and save money.
Check out this article explaining the proper use of different sous vide bags to learn more.
Is Sous Vide Cooking at Low Temperatures Safe?
Sous vide is a slow-cooking process at low temperatures. This gradual heating method ensures your food stays moist and tender.
However, others worry that sous vide temperatures are not warm enough to cook food thoroughly. More importantly, raw or undercooked food can cause pathogenic bacteria to thrive.
Cooking at low temperatures, be it sous vide or conventional cooking method, is safe provided you follow the standards.
Specifically, the Australian Food Authority recommends keeping refrigerated foods at 5°C or below. Then, keep hot foods at 60°C or above.
The reason is that bacteria thrive between 5°C and 60°C, also known as the temperature danger zone.
So, to avoid food poisoning or growing bacteria in your food, always sous vide at food-safe temperatures or 56°C or above. Also, do not sous vide food at 54°C and below for a few hours.
If you like, purchase or use an immersion circulator that alerts you when cooking within the danger zone.
Also, while immersion circulators are precise, calibration issues can still happen. So, follow these tips to ensure your temperature settings are always correct:
- Before sous vide cooking, use another thermometer to check your water bath temperature.
- Double-check the temperature calibration of your immersion circulator every few weeks.
- Use a second thermometer when cooking your food close to the temperature danger zone.
- If possible, cook your food one or two degrees higher than the original recipe settings for thorough cooking.
Is It Safe to Sous Vide Vacuum Sealed Food?
Another common concern of sous vide sceptics is the potential risk of botulism caused by Clostridium botulinum.
There are two ways how sous vide can potentially give rise to this problem.
One is that low temperatures may result in improperly cooked food, allowing the bacteria to grow. Another is cooking food in an airless or low-oxygen plastic bag that may encourage the anaerobic C. botulinum to thrive.
Food in vacuum pouches is safe from botulism if you cook it at safe temperatures. Also, immediately keeping vacuum-sealed foods in cold storage prevents the growth of food pathogens.
Here are some reminders to keep your sous vide foods free from botulism:
- Always sous vide at food-safe temperatures, 56°C or above.
- After cooking, put your vacuum-sealed food in an ice bath to lower its temperature to 5°C. Then, refrigerate or freeze your bagged food right away.
- Make sure to consume and reheat your sealed food within its lifespan. Research shows that refrigerated sous vide foods can last up to 7 days (or 52 days, depending on food type). Frozen sous vide food can last for several months.
Final Thoughts
Concerns about the sous vide method are understandable. However, according to experts and health organisations, sous vide cooking is safe, provided you follow the basic precautions.
Know the proper cooking temperatures to ensure your food is thoroughly cooked and free from harmful bacteria. Also, using the correct vacuum bags is equally vital.
So, keep the sous vide cooking reminders in mind and enjoy cooking food with precision without worries.
Check out my list of the best sous vide machines for added food safety.
