When you’re first getting started with sous vide cooking, you might have some concerns about food safety. That’s understandable and also a good thing! You always want to put safety first. So how do you know if the meat is being cooked long enough to kill harmful bacteria? And is it safe to cook food in plastic bags? Let’s take a closer look.
Sous vide cooking is one of the safest methods out there due to its control and precision. However, it’s important to learn the correct technique and not skim over the instructions so you are getting those precise results.
It’s helpful to understand a few basic points, which I’ll be covering here. These should not only help alleviate your concerns, but they’ll help you understand why certain methods exist in sous vide. Times, temperatures, and correctly using the water displacement method are all about safety and delicious results.
- Cooking in plastic is safe. Use high quality freezer bags like Ziploc or Glad.
- Proper air and hot water circulation is key.
- It’s safe to cook chicken below 165ºF (74ºC) because it’s cooked long enough to kill any harmful bacteria.
- Rapidly chill foods if you’re planning to refrigerate them instead of enjoying them immediately.
- Don’t sous vide raw garlic 🙁
Sous Vide and Plastic Safety
A common and very understandable concern is whether it’s safe to cook food in plastic. The answer is yes, it is safe! However, to be 100% safe, use high quality name-brand freezer bags like Ziploc or Glad. They have well-documented details about ingredients and they do not use any additives.
These plastic bags are not harmful when heated. They’re made of inert polyethylene. There are no small-molecule additives like BPA and phthalates, which are causing concerns in other plastic containers about having estrogen-like effects.1
Why use freezer bags? The freezer bags are made from thicker plastic, which, to be clear, doesn’t directly impact the safety of the plastic itself. However, heating plastic bags can make them weaker and more prone to tearing, which can allow water into the bag. While that in and of itself isn’t harmful, it could impact the air circulation or potentially leak raw meat juice into the container. Again, sous vide is all about precision.
If you’re not convinced, another option is to use silicone bags for sous vide cooking. As an added bonus, these are also a more environmentally friendly option since they’re reusable.
The Food Danger Zone
The primary concern for any type of food safety method is to prevent the growth of harmful bacteria (pathogens). Sous vide is obviously no exception.
Fresh foods like meats, seafood, and vegetables are all susceptible to bacteria growth, and they shouldn’t be kept for longer than two hours in what the USDA calls the “Danger Zone” of 40ºF (4.4ºC) to 140ºF (60ºC). This is a very good general rule to follow, but there are actually some instances in sous vide cooking where that rule is made to be broken. Let’s dig into why, because I was skeptical at first.
Pathogens are killed by Both Temperature and Time
It’s all about pasteurization.
Pasteurization is heating food to a temperature for a certain amount of time until the harmful pathogens are killed off. The USDA recommends cooking chicken to an internal temperature of 165ºF (74ºC) to kill any harmful bacteria, and this is why my stomach dropped the first time I saw a recipe stating to sous vide the chicken at 150ºF (65.5ºC).
As it turns out, what we’ve been taught about cooking temperatures and food safety is oversimplified (for good reason, but still). When chicken is cooked to 165ºF (74ºC), salmonella is killed off instantly.
Now check this out: Did you know that if you cook chicken to 160ºF (71ºC), it takes 14 seconds to kill Salmonella? Or if you cook the chicken to 155ºF (68ºC), it takes 50 seconds to kill it? Neither did I. It’s fascinating stuff, at least I think so. According to the USDA, most food pathogens are killed at 130ºF (54.5ºC) if you give them the right amount of time.2
Because of this, most sous vide recipes are going to start at a minimum of 130ºF (54.5ºC).
Use an Ice Bath To Rapidly Chill Foods
Food isn’t safe indefinitely, and the Danger Zone temperatures do still apply after the sous vide process is finished. If you’re cooking in advance and don’t plan to enjoy the food immediately, you’ll want to use an ice bath. This will rapidly drop the temperatures before refrigeration, preventing bacterial growth.
All you need to do is fill a large bowl with ice and cold water. Next, add the bag and let it chill, completely submerged, for about 10-15 minutes. Then you can either transfer the food to a different storage container, or leave it in the freezer bag if you plan to reheat using the sous vide. Place in the refrigerator and you’re good to go.
Cook Your Garlic First
I’ve seen a lot of conflicting information about raw garlic in sous vide cooking, so to play it extra safe, I’m siding with the experts at Cook’s Illustrated and America’s Test Kitchen. If you want to use fresh garlic with your sous vide, cook it before placing it in the bag (sauté it, roast it, whatever you prefer).
Raw garlic is susceptible to botulism, especially when exposed to the type of warm environment created by sous vide cooking. It’s not worth taking the risk, in my opinion. If you don’t feel like taking the extra step to cook the garlic, either omit it entirely or use dried, granulated garlic.
1. “Sous Vide and Plastic Safety” facts are sourced from Sous Vide at Home by Lisa Q. Fetterman.
2. Pasteurization time and temperature facts are sourced from Sous Vide For Everybody by America’s Test Kitchen