Slow Cooker Apple-Cinnamon Steel-Cut Oatmeal

Ingredients

• Nonstick cooking spray or a small amount of neutral oil
• 1 cup steel-cut oats (not rolled or quick-cooking oats)
• 4 cups water
• 2 medium apples, peeled if desired, cored and cut into 1/2-inch pieces
• 1 1/2 teaspoons ground cinnamon
• 1/4 teaspoon fine salt
• 1 teaspoon vanilla extract
• 2 tablespoons maple syrup, optional
• Milk, chopped pecans, or additional apple for serving, optional

Preparation and cooking

1. Lightly grease the inside of a 3- to 4-quart slow cooker. Add the steel-cut oats, water, apples, cinnamon, and salt; stir once.
2. Cover and cook on Low for approximately 6–8 hours, or on High for 3–4 hours. Begin checking at the early end because slow cookers vary. The oats should be tender but still slightly chewy.
3. Stir thoroughly, scraping the sides and bottom. Stir in vanilla and maple syrup, if using. For a looser texture, add hot water or milk a few tablespoons at a time.
4. Serve promptly with optional milk, pecans, or fresh apple.

Choose the right oats and cooker

Use traditional steel-cut oats. Rolled oats and quick-cooking oats absorb water differently and can become pasty during a long cook. A 3- to 4-quart cooker keeps this batch deep enough to cook evenly; in a larger cooker, the thinner layer may finish sooner and form more of a crust around the edge.

Cook on Low or High, never Warm. Warm is intended to hold already-hot food, not cook the oats. Follow the appliance manufacturer’s fill limits and timing guidance. If your cooker runs hot, check early the first time you make the recipe.

Overnight planning

Measure and cut the ingredients using the site’s mise en place routine. Start the cooker only when the timing puts breakfast inside the 6–8 hour window. Do not use a delayed start. This water-based version avoids leaving milk at room temperature before cooking; add milk after the oatmeal is hot and finished.

Texture fixes

• Too thick: Stir in hot water or milk, a few tablespoons at a time.
• Too loose: Stir well and let the oatmeal stand uncovered for 5–10 minutes. It thickens as it cools.
• Cooked edge: Stir it into the oatmeal if it tastes pleasant. If it is scorched, leave that portion behind and reduce the time on the next batch.
• Firm oats: Add 1/4 cup hot water, cover, and continue on High in 15-minute intervals until tender.

Safe storage and reheating

Transfer leftovers to shallow containers and refrigerate within two hours. Keep the refrigerator at 40°F or below and use refrigerated oatmeal within 3–4 days. Reheat only the portion you need on the stove or in the microwave to 165°F, stirring and adding water or milk as needed. Do not use the slow cooker to reheat chilled oatmeal.

See the full slow-cooker leftovers guide for cooling, freezing, and reheating steps.

Safety sources

Guidance checked October 19, 2026: USDA slow-cooker safety and USDA leftovers guidance.