When I lift the slow cooker lid, the broth smells of thyme and sage, and the turkey is tender enough to carve into generous slices. The first time I made this, I expected a breast that needed constant attention. Instead, this slow cooker turkey breast takes a little hands-on prep, then cooks gently while the covered cooker does its work.
The part that makes the seasoning count is working softened butter under the skin as well as over the outside. It keeps the herbs close to the meat, where they can season more than just the surface. I also use onion quarters as a bed rather than letting the breast sit directly in the broth. The result is savory, moist turkey with a simple pan liquid underneath and slices that look right at home on a holiday table or a weeknight plate.
Kitchen Note
Stir the softened butter until the herbs and seasonings are spread evenly through it. A uniform mixture is easier to distribute, so you don’t end up with one patch of turkey much more heavily seasoned than another.
Save this slow cooker turkey breast for tender slices seasoned with thyme, sage, and garlic butter.
Why the Turkey Sits on Onion Quarters Instead of Swimming in Broth
It’s natural to think a larger pool of liquid will protect turkey breast from drying out, but this slow cooker isn’t meant to poach the meat. The chicken broth sits at the bottom, and the onion quarters create a bed for the breast to rest on. As the cooker heats, its covered environment holds moisture around the turkey while the broth and onion add savory aroma.
Adding extra broth changes that balance without solving the real challenge, which is cooking a lean breast only until it’s done. Keep the turkey above the liquid and skin-side up. The broth remains useful after cooking, too: it catches the drippings and softens the onion as the turkey cooks. The skin won’t turn crisp in a slow cooker, so think of this as a tender, herb-seasoned roast-style breast rather than a crisp-skinned oven roast. That difference is worth knowing before you lift the lid.
What the Butter, Herbs, and Onion Each Bring to the Pot
- Yellow onion — Quartering the onion gives it enough size to form a sturdy bed under the breast. A yellow onion’s mellow sweetness suits the thyme and sage; there’s no need to dice it finely since it’s there to flavor the cooking liquid as well as support the turkey.
- Low-sodium chicken broth — This provides the liquid at the base of the cooker without making the finished juices overly salty. A basic store-brand broth works well here. Unsalted chicken broth is a useful swap if that’s what you have; regular broth can make the finished liquid taste saltier.
- Unsalted butter — Softened butter holds the dried herbs and spices together and makes them easy to spread beneath the skin. Unsalted butter also lets the kosher salt stay in control. Use butter that’s soft enough to stir, not melted and runny.
- Thyme, sage, black pepper, and garlic powder — Dried herbs suit the long, covered cook and disperse evenly through the butter. Fresh herbs aren’t a direct one-for-one replacement here; dried herbs are the practical choice for this seasoning paste. Break up any clumps of garlic powder before rubbing the mixture onto the turkey.
- Bone-in, skin-on turkey breast — The bone helps support the breast and gives you a useful landmark when checking the thickest meat. Choose a breast in the stated size range, and thaw it completely before cooking so it heats evenly within the cooking window.
The Five Stages That Keep This Slow Cooker Turkey on Track
Build an Onion Bed
Arrange the quartered onion across the bottom of a 6-quart slow cooker, then pour in the chicken broth. Spread the onion pieces enough to support the turkey rather than leaving one high pile in the middle. They don’t need to cover every inch of the bottom. This gives the breast a bed above the broth and leaves the liquid free to collect beneath it.
Mix the Seasoned Butter
Stir the softened butter with the kosher salt, black pepper, dried thyme, dried sage, and garlic powder in a small bowl. Work the mixture until the seasoning looks evenly distributed, with no big clumps of herbs or garlic powder. If the butter is cold and firm, it’ll be hard to spread without tugging at the skin. Softened butter should smear easily while still holding together.
Season Beneath the Skin
Pat the fully thawed turkey breast dry before you start; a dry surface makes the butter easier to spread. Gently loosen the skin with your fingers, working slowly so it stays intact, then spread the butter mixture underneath and over the outside. Reach across as much of the breast as you can rather than leaving all the seasoning in one spot. Set the turkey skin-side up on the onion bed.
Cook to the Thermometer Reading
Cover the slow cooker and cook on LOW for 5 to 6 hours or HIGH for 3 to 4 hours. Insert a thermometer into the thickest part of the breast, taking care not to touch bone; the turkey is ready when it reads 165°F. Bone can give a misleading reading, so reposition the probe if it lands against the bone. Cooking time varies with the size and shape of the breast, which is why the thermometer decides when it’s done.
Rest Before Carving
Transfer the turkey to a cutting board and leave it undisturbed for 15 minutes before carving. This pause gives the juices time to settle so they’re less likely to run across the board as soon as you slice. Use a sharp carving knife and cut steady slices through the breast meat. Spoon a little of the cooking liquid over the carved turkey if you’d like the plate to stay moist.
Three Flavor Changes That Still Suit a Slow Cooker Turkey Breast
Make the Seasoning Dairy-Free
Replace the softened butter with the same amount of olive oil and stir in the salt, pepper, thyme, sage, and garlic powder. The mixture will be looser and less creamy, but it still carries the seasoning beneath the skin. Rub it on gently so it coats the meat rather than running off in one place.
Add a Little Lemon Brightness
Stir the finely grated zest of one lemon into the butter mixture before seasoning the turkey. The citrus lifts the savory thyme and sage without adding extra liquid to the rub. Keep the lemon juice out of the cooker; the zest gives a fragrant note without changing the broth underneath.
Give the Herb Butter a Smoky Kick
Add smoked paprika and a small pinch of cayenne to the butter mixture for a warmer, gently smoky seasoning. The paprika brings color and depth, while cayenne adds heat; leave the cayenne out if you want the flavor without the spice. Keep the onion and broth as they are so the seasoned turkey still cooks over the same aromatic base.
Storage and Reheating
- Refrigerator: Store carved turkey in a covered airtight container for 3 to 4 days. The meat firms up when cold, so add a little broth before reheating.
- Freezer: Freeze carved portions in airtight freezer-safe packaging for up to 3 months for best quality. Thaw them in the refrigerator before reheating.
- Reheating: Warm covered portions in the microwave or in a saucepan over low heat with a splash of broth, until hot throughout. Avoid reheating turkey in the slow cooker; it warms too gradually.
Questions That Come Up When Cooking Turkey Breast in a Slow Cooker
Slow Cooker Turkey Breast
Ingredients
Equipment
Method
- Arrange the onion in the bottom of a 6-quart slow cooker.
- Pour the chicken broth over the onion.
- Stir the butter, salt, pepper, thyme, sage, and garlic powder together in a small bowl.
- Pat the turkey breast dry.
- Gently loosen the turkey skin.
- Spread the butter mixture under the skin and over the outside.
- Set the turkey breast skin-side up on the onion.
- Cover and cook on LOW for 5 to 6 hours or HIGH for 3 to 4 hours, until a thermometer inserted into the thickest part without touching bone reads 165°F.
- Transfer the turkey to a cutting board.
- Rest for 15 minutes before carving.