We all know slow cookers are ideal for the busy person, but if you are leaving the house at 7:00 a.m. and not returning for 12 hours, this long, slow cooking method may not work for you, since most recipes call for cooking times of eight hours at the most. Some cooks seize upon what they think is a logical solution: plugging 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.
Any number of these timers are available at retailers, most of them now using digital mechanisms.
But using a delayed timer with your slow cooker is considered dangerous from both a health and electrical safety point of view.
Modern slow cookers come with a variety of high-tech programmable features, but one thing they don't offer is delayed start time. The reason you won't find delayed start timers built into slow cookers is a matter of 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 food-borne illness, particularly if you've placed raw meat in the cooker.
Most slow-cook meals require no more than 8 hours of cooking time. Raw meat can sit out for a maximum of two hours before bacteria begins 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.
Some cooks argue that if frozen food is put into the slow cooker, it will thaw gradually and a delayed start is therefore safe. Don't be fooled into believing this. Allowing frozen food to thaw inside a slow cooker is the same as allowing it to thaw on the countertop, a technique the USDA 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.
Although it's fairly common for cooks to place frozen food into a slow cooker for immediate cooking, this is not recommended practice, 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 degrees and 140 degrees. Cooks who argue that they have done this dozens of times with no ill effects have simply been lucky: all it takes is one contaminated meal to create a critical health problem for anyone susceptible—such as an elderly person, young child, or someone with a challenged immune system.
If it's unsafe to immediately cook frozen foods in a slow cooker, then allowing foods to sit in a slow cooker for several hours before they begin to heat is even more hazardous. Make no mistake: delayed start is a bad idea for slow cooking.
There are also electrical hazards to using delay timers with an appliance such as a crock pot or slow cooker.
You may use delayed timers for certain fixtures and appliances around your house, such as lamps, but in general, electricians don't 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 GFCI outlet, it can also trip when the heating element of a slow cooker comes on. When a circuit breaker trips, this means that any other appliances, lights, or outlets on the same circuit will shut off as well. And if you're not home, you won't 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.
Just because you can't use a delayed timer with your crockpot doesn't mean a slow cooker can't work for you. Since stewy, slow-cooked meals freeze beautifully, try doing your cooking on the weekends when you're 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're ready to eat it, then you can quickly heat it on the stove or in the microwave when you get home.
Another option that might work for you is a slow cooker that has a timer that allows the cooker to switch to a "keep warm" setting once the cooking time is reached. This will keep your food at a safe heat level for another hour or two until it's time for dinner. There are several on the market—one option to try is the Crock-Pot eLume Slow Cooker.