Whether at home or at the restaurant, making large batches of food can present a special food safety challenge. The food danger zone–that place between 41 and 140 degrees where pathogens grow most quickly–can take a long time to get through when you have a large batch of chili, soups, gravies, sauces, or other liquid food product.
The water in these products holds an awful lot of heat, and getting a big batch down to refrigerated temperature can take forever. If you do not help this process along, you could sicken your family or patrons. The food must absolutely get from 140 to 70 degrees in two hours, and must be cooled from 70 to 40 degrees in no more than four. If either step takes too long, the food is unsafe and must be thrown out.
The first thing that you need is an accurate probe thermometer. You can use an inexpensive bimetal thermometer, or go with a digital. I a prefer dishwasher-proof, tip-sensitive, digital thermometer, as it tends to be fast, accurate, and won’t get ruined if I drop it into the sink. You will want to keep tabs during the cooling process, and this is the best tool for the job.
Here are some strategies for cooling bulk liquids:
Cooling Paddles: These have become one of the most common ways to cool liquids in a commercial kitchen. The convenience, ease of use, and safety of the paddles is a real selling point. The paddles need to be filled with water and placed in the freezer overnight. They have a large surface area, so they can cool soups fast. What makes these more safe than other methods is that you can cool right in the cooking vessel–there is no pouring hot soup into other containers or carrying the cooking pot around.
Shallow metal pans: Another method of cooling liquids involves increasing the surface area and reducing the mass of the soup. You can pour the hot liquid into several full-sized, 2-inch deep, metal steam-table pans and place them in an area where they are least likely to encounter cross contamination. This will help the cooling considerably, but there are problems. First, pouring all of that soup into the pans can be dangerous. Also, handling a shallow steam-table pan filled with liquid is not exactly easy, and can result in spills.
Ice Water Bath: Fill a clean sink with ice and a little water to make slush. Place the cooking vessel in the slush carefully. As long as you are OK with tying up one of your sinks, this is a good method of cooling; providing you have taken the appropriate cautions against contamination, and are very careful when moving the pot of hot liquid. If you find that this method is not working fast enough, separate the food into smaller metal pots (like vegetable insets or bain marie pots) in order to speed the process.
Of these methods, I very much prefer the cooling paddle method. Not only is there less chance of cross contamination, but it is much safer for kitchen workers. Burns from liquids can be especially brutal and anything that eliminates the transport of boiling hot liquids greatly lessens the chance of burns. But any way you do it, proper cooling of liquids will help keep your family or patrons from barfing, and that is paramount. And, if for some reason you are unable to get your liquid foods through the danger zone in time: discard them and start over!