How to Use a Slow Cooker
Use a slow cooker safely. Choose low or high, layer vegetables under the meat, cut the liquid, keep the lid on, and follow the food safety rules for thawing, kidney beans, and leftovers.
You will end up with a slow cooker meal that is cooked through and safe to eat, plus the rules behind it: which setting to use, how to layer the pot, how much liquid to add, and when to leave the lid alone.
A slow cooker cooks food slowly at a low temperature. The U.S. Department of Agriculture's page on slow cookers and food safety says the low heat helps less expensive, leaner cuts of meat become tender and shrink less, and that the direct heat from the pot, the long cooking time, and the steam inside the covered pot combine to destroy bacteria.
Two safety rules apply before anything goes in the pot. Thaw meat and poultry first, and boil dried red kidney beans first. Step 2 covers both, and step 6 covers leftovers and power cuts.
A slow cooker (any size from 4 to 8 quarts works) A cutting board and knife for prep Measuring cups or a kitchen scale A food thermometer Ingredients suited for slow cooking (tough cuts of meat, root vegetables, beans, broths)
Choose low or high
Cook on low or high. High cooks faster than low. For all-day cooking and for less-tender cuts of meat, use low, the setting the USDA page suggests for both. Go by the time in your recipe, because makers give different ranges. Hamilton Beach tells owners to look for recipes that call for 4 to 5 hours on high or 6 to 8 hours on low, and a Crock-Pot manual says most uncooked meat and vegetable combinations need at least 8 hours on low. To move a recipe from one setting to the other, Crock-Pot's rule is that 1 hour on high equals about 2 to 2.5 hours on low. When the pot holds meat or poultry, turn the cooker to high for the first hour, then down to the setting your recipe calls for. Colorado State Extension's slow cooker safety page calls this highly recommended for meat and poultry. The danger zone, where bacteria grow rapidly, runs from 40°F to 140°F (4°C to 60°C), and an hour on high shortens the time the food spends in it. If you have to leave before the hour is up, the USDA says cooking on low the entire time is still safe. The warm setting is for holding food that is already cooked (step 6), and both Crock-Pot and Hamilton Beach say not to cook on it.
Good to know: If your cooker is programmable, set the cook time and let it switch to warm on its own. Hamilton Beach's programmable slow cooker manual describes the cooker switching to warm at the end of the set time and turning off after 14 hours in total. Check your manual to see whether yours does the same.
Thaw, pre-boil, and cut the ingredients
Thaw meat and poultry completely. The USDA says to always thaw meat or poultry before putting it into a slow cooker, because, as Colorado State Extension puts it, frozen pieces might not reach 140°F quickly enough. Thaw in the refrigerator. If you are short on time, thaw the meat in cold water in a leak-proof bag, change the water every 30 minutes, and cook it as soon as it has thawed. Crock-Pot's own manual allows frozen meat if you first add at least 1 cup of warm liquid and cook it for longer. The USDA, Colorado State Extension, and Hamilton Beach all say to thaw first, so thaw first. Keep the thawed meat and the cut vegetables in the refrigerator until you load the pot, because the USDA notes that a slow cooker can take several hours to reach a temperature that kills bacteria. Boil dried red kidney beans before they go in. They carry a natural toxin that boiling destroys, and Illinois Extension warns that heating them slowly in a slow cooker may make them more toxic rather than less. As few as four undercooked beans can cause vomiting and diarrhea. Soak dried kidney beans for at least 5 hours, pour that water away, and boil them briskly in fresh water for 30 minutes. Canned kidney beans are already cooked and safe to add straight from the can. Then cut everything to size. The USDA notes that vegetables cook more slowly than meat and poultry in a slow cooker, so cut root vegetables like carrots, potatoes, and turnips into pieces no larger than 1 inch (2.5 cm). Meat can stay in larger pieces. The USDA says large cuts of meat and poultry cook safely in a slow cooker and points you to the instruction booklet for the sizes your model takes. For faster cooking, cut meat into 2-inch cubes. Dice onions, garlic, and other aromatics small, because they break down during long cooking and become part of the liquid.
Good to know: Brown the meat in a hot pan before it goes in, 3 to 4 minutes per side. Crock-Pot's manual gives two reasons. Browning lets you drain off fat before slow cooking, and it adds depth of flavor. It is optional, so skip it when you are short on time.
Layer ingredients in the right order
Fill the pot between half and two-thirds full. That is the range Colorado State Extension gives for safe, even heating, and makers set their own limits. Crock-Pot's manual says half to three-quarters full, and Hamilton Beach's says at least half full and no closer than 1 inch to the rim, so check yours. Put the vegetables in first. The USDA and Crock-Pot both say so, because vegetables cook more slowly than meat, and Crock-Pot adds that placing them near the bottom or sides of the pot helps them cook. Put the meat on top of the vegetables. Then pour in the liquid, in the amount from step 4. Hold back the ingredients that break down over hours of cooking, which are fresh herbs, spinach and other leafy greens, pasta, dairy (milk, cream, sour cream, cheese, yogurt), and pre-cooked grains like rice. Add them near the end. The timing depends on the maker. Crock-Pot's manual says to add milk, cream, and sour cream during the last 15 to 30 minutes and to part-cook pasta on the stove before it goes in. Hamilton Beach's says to add pasta, seafood, milk, cream, and sour cream 2 hours before serving. Go by your own manual.
Get the liquid amount right
Use about half the liquid a stovetop or oven recipe calls for. That is Crock-Pot's rule for converting a recipe, with an exception for recipes that contain rice or pasta, and Hamilton Beach's manual explains why. A slow cooker allows very little evaporation. The lid traps the steam, and the juices from the meat and vegetables stay in the pot, so the level rises as the food cooks. When meat or poultry is in the pot, the level matters more than the cup count. Colorado State Extension says the water or stock should almost cover the ingredients, to create steam and carry heat through the whole pot. A vegetable dish needs less, but it still needs some. Hamilton Beach warns that a vegetable casserole needs liquid in the recipe to prevent scorching on the sides of the crock. If the finished dish is too thin, switch to high, stir in a slurry of 1 tablespoon cornstarch mixed with 1 tablespoon cold water for each cup of liquid in the pot, and cook with the lid off until it thickens. That is the ratio in our guide on how to make gravy. If the dish is too thick, add liquid. Hamilton Beach's manual notes that liquid can go in later.
Heads up: Crock-Pot and Hamilton Beach both warn against sudden temperature changes, such as adding refrigerated foods or cold liquids to a heated pot, because the stoneware cannot take the shock. If a dish needs more broth or water partway through, heat it first.
Keep the lid on
Every time you lift the lid, you release the trapped heat and steam. Colorado State Extension, the source linked in step 1, puts the cost of each peek at a 10°F to 15°F drop inside the pot and about 20 minutes to recover the lost heat, which extends the cooking time and raises the food safety risk. You do not need to stir. Hamilton Beach's manual says stirring is not necessary when slow cooking, with one exception, which is an occasional stir when cooking on high. Open the lid for three things only: to add the late ingredients from step 3, to stir in a thickener at the end, and to check for doneness at the end of the recipe's time. When you check meat or poultry, use the food thermometer. Colorado State Extension gives 165°F (74°C) as the minimum safe temperature to confirm whenever there is any doubt about doneness.
Keep the cooked food safe
Food stays safe for as long as the cooker is operating, according to the USDA. The rules below start when the heat stops. Do not leave cooked food in a slow cooker that is switched off for more than 2 hours. Move leftovers into shallow covered containers and refrigerate them within 2 hours of the end of cooking. Do not put the whole crock in the refrigerator. Hamilton Beach's manual says the contents take too long to cool that way. Do not reheat leftovers in the slow cooker. The USDA says to reheat cooked food on the stove, in a microwave, or in a conventional oven until it reaches 165°F (74°C). After that, the hot food can go into the slow cooker to stay hot for serving, at 140°F (60°C) or above.
Heads up: If the power goes out while you are away, throw the food away, even if it looks done. That is the USDA's rule. If you are home when it goes out, finish cooking right away by other means, such as a gas stove or an outdoor grill. If the food was already fully cooked when the power went out, it stays safe in the cooker for up to 2 hours.
If the food is undercooked at the end of the recipe's time, work through Hamilton Beach's troubleshooting list. Check whether the cooker was on warm instead of low or high, whether the power was interrupted, whether you used a high-setting time on low, whether the crock was filled past the maker's limit, and whether the lid sat properly on the crock. If the food is overcooked, check the fill level and the setting. Hamilton Beach says to check for doneness 1 to 2 hours earlier than the recipe states when the crock is only half filled, and its list also asks whether you used a low-setting time on high. If an older cooker keeps undercooking, test it. Colorado State Extension's test is to fill the pot half to two-thirds with tap water, heat it on low for 8 hours with the lid on, and read the water quickly with a food thermometer. It should measure 185°F to 200°F (85°C to 93°C). Below 185°F, the cooker does not heat food well enough to be safe, and the extension service says to replace it. For a big batch, our guide on how to meal prep covers cooling and storing it for the week. FAQ 1 below covers overnight cooking, FAQ 2 converting a recipe, and FAQ 4 choosing a size.
Questions we get asked about this
Answers from experience, not a textbook.
Yes. The USDA says food stays safe for as long as the cooker is operating, and that cooking on low the entire time is safe, including while you are out at work. Set the cooker on a dry, stable surface with at least 2 inches of space around it, and plug it directly into a wall outlet, not an extension cord, as Colorado State Extension advises. Check your manual for its own clearance, because Crock-Pot asks for 6 inches from the wall and on all sides. The one overnight risk is a power cut you sleep through. If you wake to find the power went out during the night, treat it the way the USDA treats a cut while you were out, and throw the food away.
Change three things: the liquid, the time, and the late ingredients. Use about half the liquid (step 4). For the time, a Crock-Pot manual gives a conversion guide. A recipe that cooks for 15 to 30 minutes on the stove or in the oven takes 4 to 6 hours on low or 1.5 to 2 hours on high. One that cooks for 35 to 45 minutes takes 6 to 10 hours on low or 3 to 4 hours on high. One that cooks for 50 minutes to 3 hours takes 8 to 18 hours on low or 4 to 6 hours on high. These ranges are for adapting an oven or stove recipe, so they run wider than the rule in step 1, which is for moving a slow cooker recipe from one setting to the other. Both come from the same Crock-Pot manual. Hold dairy and fresh herbs for the end, and part-cook pasta on the stove before it goes in (step 3). If the original recipe uses cooked rice, Crock-Pot says to stir in raw rice instead and add 1/4 cup of extra liquid for each 1/4 cup of rice.
Yes, as long as it is fully thawed (step 2). Browning it first is optional. Keep raw meat in the refrigerator until the moment you load the pot. Hamilton Beach's manual says never to let raw or undercooked meat sit at room temperature in the slow cooker, and to start cooking as soon as the meat is in the crock. If you prepare ingredients the night before, the USDA says to store the cut meat and the vegetables separately in the refrigerator.
Size it by the batch you cook, using the fill range from step 3. Filled half to two-thirds full, a 4-quart cooker holds 2 to about 2.7 quarts of food (8 to 11 cups), a 6-quart holds 3 to 4 quarts (12 to 16 cups), and an 8-quart holds 4 to about 5.3 quarts (16 to 21 cups). Pick the size whose range matches the amount you want to cook. For roasts, Crock-Pot's manual suggests boneless cuts of 2.5 to 5 pounds for a 5-quart cooker and 3 to 6 pounds for a 6-quart. Do not buy much bigger than your usual batch, because a crock that runs under half full falls outside every fill range in step 3.
Check three things. Start with the liquid. Colorado State Extension says liquid that almost covers the ingredients also minimizes scorching, and Hamilton Beach warns that a vegetable casserole needs liquid in the recipe to prevent scorching on the sides of the crock. Then check the fill level. Hamilton Beach's troubleshooting list puts a crock that was less than half full among the causes of overcooked food. Last, check that you did not use a low-setting time on high. If none of those explains it, start checking for doneness earlier the next time you make the dish.
No. A liner is a disposable bag that sits inside the crock so food does not stick to it, and it is optional. Without one, wash the crock in hot, soapy water or in the dishwasher. The Crock-Pot and Hamilton Beach manuals both list their crocks as dishwasher safe, but check your own. Let the crock cool first or use hot water, because Crock-Pot warns not to pour cold water into hot stoneware, and do not use abrasive cleaners on it.