Go with ember and chatnoir’s advice!
Here is a practical example.
I cook large batches of spagetti sauce. When ready, I turn off the stove then prepare my vacuum bags for the volume of sauce,(never less than 15 bags), the sauce ‘cools’ while I’m preping bags. When the bags are ready, I fill the sink with water, ice, & about 1 ½ cups salt, then mix. Now, I fill the bags with 2 ½ cups of the still hot (about 150-160 degrees F) sauce, vac seal the bag with the filling in the bottom hanging over the counter edge so liquid won’t get to the seal area. When sealed, I flatten the sauce bag out so that the sauce occupies the whole bag and is about 1inch thick. Now the bag goes into the sink of ice water, mix after each bag, add more ice as necessary. (Collect lots of ice cubes during the week before the cook.). When all of the bags are cold, take them out, dry off, put them into the freezer.
The whole purpose of the ‘shock’ cooling is to get your food from hot to cold as rapidly as possible. This is to pass through the temperature zone where bacteria, yeast, and moulds live & breed as fast as possible so that you get no bacterial growth in your food.
Happy cooking, (and storage)!