Slow cookers and multicookers that have multiple cooking options like the Instapot, for example, are ideal for the busy person. But, if you use the slow-cook option, and if you are leaving the house at 7 a.m. and not returning for 12 hours, using a long, slow-cook method may not be a good idea.
Most recipes call for cooking times of eight hours at the most. You might think a logical solution is to plug the crockpot into a delayed-start timer—the same type of device that can be used to make a lamp or appliance turn on and off automatically at preset times. But, a preponderance of evidence suggests that using a delayed timer with your slow cooker is considered dangerous from both a health and electrical safety point of view.
Health and Food Safety
Modern slow cookers come with a variety of high-tech programmable features, but one thing the device does not offer is a delayed start time. And, there is a reason for that. A delayed-start timer can negatively impact food safety. If you have food sitting on your countertop for hours before the cooker turns on, you have created the ideal breeding ground for bacteria that could lead to foodborne illness, particularly if you have placed raw meat in the cooker.
Most slow-cook meals require no more than eight hours of cooking time. Raw meat can sit out for a maximum of two hours before bacteria begin to multiply, so if you have a 12-hour day and want dinner ready when you walk in the door, your ingredients will be exposed to the potential for bacteria for at least four hours—possibly more than twice the safe time recommended. It is also not safe for the cooked food to sit on the counter for hours afterword, either.
You may believe that if frozen food is put into the slow cooker, it will thaw gradually and a delayed start is therefore safe. But, you can poke a hole in this logic. Allowing frozen food to thaw inside a slow cooker is the same as allowing it to thaw on the countertop, a technique the U.S. Department of Agriculture warns against.
A package of frozen meat or poultry left thawing on the counter more than 2 hours is not at a safe temperature. Even though the center of the package may still be frozen, the outer layer of the food is in the "Danger Zone" between 40 and 140 F—at a temperature where foodborne bacteria multiply rapidly.—USDA
Although it is fairly common practice to place frozen food into a slow cooker for immediate cooking, this is not recommended, either. Frozen foods come up to a safe temperature quite gradually under the slow steady heat in a slow cooker, and thus spend too much time in the dangerous zone between 40 F and 140 F. You may argue that you have done this dozens of times with no ill effects, but you may have been simply lucky. All it takes is one contaminated meal to create a critical health problem for those susceptible to bacterial infections—such as an elderly person, young child, or someone with a challenged immune system.
If it is unsafe to immediately cook frozen foods in a slow cooker, then allowing foods to sit in a slow cooker for several hours before it begins to heat is even more hazardous. Delayed-start cooking is clearly a risky proposition.
There is the risk of an electrical hazard to using delay timers with an appliance such as a slow cooker or multicooker. You can use delayed timers for certain fixtures and appliances around your house, such as lamps, but in general, electricians do not recommend using these units for anything that contains a heating element, such as slow cooker.
The electrical load placed on the delayed timer as the heating elements begin to draw current can be too much, causing the circuit breaker controlling the outlet to trip.
If the slow cooker is plugged into a ground-fault circuit interrupter outlet (a fast-acting circuit breaker designed to shut off electric power in the event of a ground-fault), it can also trip when the heating element of a slow cooker comes on.
When any circuit breaker trips, this means that any other appliances, lights, or outlets on the same circuit will shut off as well. And if you are not home, you will not be aware of this until you walk in the door from work expecting dinner to be ready, only to find the meal ruined and the kitchen dark.
Crockpots to the Rescue
Just because you cannot use a delayed timer does not mean that your slow cooker is useless. There are two simple solutions.
Make sure you get a get a slow cooker with a "keep warm" option on it. The best news is that most late-model slow cooker and multicookers have this feature. The "keep warm" setting will keep your food at a safe heat level for another hour or two until after the cook time is complete, and usually when it is time for dinner. If you have an old model or a hand-me-down from eons ago, this might be one of the best excuses you may finally need to say "out with the old and in with the new."
And, if you nostalgically want to hold on to that family heirloom of a crockpot, then there is hope for you, too. Since stews and slow-cooked meals freeze beautifully, try doing your cooking on the weekends when you are home. Cool the food completely and package it in a vacuum-seal bag or a freezer-safe container. Freeze or refrigerate the meal until you are ready to eat it, then you can quickly heat it on the stove or in the microwave when you get home.