Sous Vide Cooking for Consumers - Recognizing the Risk

Sous vide cooking is gaining in popularity among consumers.  Sous vide is essentially cooking food in a sealed bag at low cooking temperatures (140F to 180F) for a long period of time. Cooking product at low temperatures in a sealed bag has advantages for flavor retention and tenderization. Unfortunately, there are some serious food safety issues that consumers may be unaware.

Food safety issues arise when the food is not adequately cooked, when cooled incorrectly, or when product is later held at incorrect temperatures.   The first concern is that the food will not reach high enough temperature to kill pathogenic vegetative cells like Salmonella or E. coli (STEC).  In traditional cooking, product is exposed to higher temperature and the center point then rises to meet that temperature.  Our standard endpoint cooking temperatures of 165F for 15 seconds for internal chicken temperature provides sufficient kill that we don't need to worry about Salmonella or Campylobacter.  With sous vide cooking, lower temperatures for longer times are used.  So the concern is that will there be sufficient heat to eliminate vegetative pathogens such as Salmonella or Campylobacter.  For traditional consumer cooking temperatures, we have ample scientific support. But for sous vide, while there is some scientific validation for commercial processing, there is less for consumer at-home cooking.  Generally people count on the direction provided by equipment manufacturers.  How valid are those directions?  And what about when people start to vary from those directions?  Perhaps they start with frozen chicken vs thawed chicken, or they decide to process at 148 instead of 155?

The other concern is cooling.  The temperatures used will not eliminate sporeforming pathogens such as Clostridium botulinum or Clostridium perfringes and so if product is not cooled quickly enough, or if product is left at room temperature for an extended time before consumption, these organisms will grow, especially in a vacuum sealed environment.  Commercial operations that use sous vide processing are required to have tight controls on cooling and refrigerated or frozen storage.  Will consumers do the same?  Fish is a particular concern because the risk of low-temperature growing Clostridium botulinum.

Photo courtesy of Zach Lampich

Consumer Reports
https://www.consumerreports.org/kitchen-appliances/sous-vide-tools-review-anova-joule/
Sous Vide Tools That Up Your Game in the Kitchen

Consumer Reports put the Anova and Joule sous vide cookers to the test to find out if slower really is better



By Kimberly Janeway
December 02, 2017

The Instant Pot craze is all about saving time. Sous vide cooking takes the opposite approach. Plan ahead, wait a while—and you’ll be richly rewarded.

Restaurants have long used the sous vide technique, and in recent years, manufacturers have introduced sous vide tools for the home cook, promising succulent salmon, the best steak you’ve ever had, and impossible-to-screw-up eggs Benedict.

The term sous vide means “under vacuum” in French. And in sous vide cooking, food sealed in a plastic bag is placed in a water bath, after the sous vide cooker has heated the water to a point that’s below, or even well below, its boiling point.

Consumer Reports tested two sous vide tools, the Anova Precision Bluetooth model, $149 (shown above; a WiFi version is also available), and the Joule, $199. Cooking times are longer than cooking the same food in an oven or on a rangetop, but our tests found that the investment in time pays off.

Here's how sous vide works. Simply plug in the sous vide device, place it in a pot of water, set your desired temperature, and, within minutes, it heats the water to the set temperature. Unlike food that’s cooked on a rangetop or in an oven, where the outside of the food cooks to a higher temperature than the inside and timing is everything, the water stays at that precise temperature throughout the cooking process.

The water circulates so that the food is brought to (and maintains) that same temperature, and the plastic bag ensures that the food inside holds on to its juices and flavor.

Food doesn’t have to be vacuum-sealed for this technique to work, and there’s no need to hover. "Put meat or fish, whatever you're cooking, in a high-quality, resealable plastic bag and season," says Bernie Deitrick, a CR test engineer. "Force any air out of the bag, seal, and drop into the pot of water."

CR Test Results

We cooked pork tenderloin at 140° F until medium doneness, which took an hour. Afterward, you can quickly sear the meat to give it a crispy finish. We also cooked thick skinless chicken breasts in water set to 149° F for 2 hours.
Both the Anova and Joule maintain set temperatures and deliver excellent results. Staffers raved about the juicy, tender meat and poultry. That’s because the food cooks to the same even temperature throughout.

Here’s a comparison of the Anova and the Joule, either of which would be a great addition to your kitchen-equipment lineup or as a gift for any foodies you know.
For comparison of units -https://www.consumerreports.org/kitchen-appliances/sous-vide-tools-review-anova-joule/