This Slow Cooker Sweet & Sour Chicken creates a sweet tangy sauce, that coats tender slow cooked chicken. This takeaway style dish does not include the crispy chicken, but you don’t miss it!

Getting the sweet–sour balance right
This sauce should taste bright and rounded, not sugary. The combination of vinegar and pineapple juice gives a softer tang, instead of a sharp hit from just one.
The brown sugar is there to smooth everything out, not take over. Too much and it quickly tips into overly sweet, especially after a few hours in the slow cooker.
Once the sauce has thickened, always taste it. Slow cooking softens flavours slightly, so this is where you adjust it if needed.

How to avoid a thin, watery sauce
The biggest thing to remember is that the chicken will release liquid as it cooks. That’s why the starting sauce is measured, it’s enough once everything combines.
Adding some pineapple at the end helps here. It keeps the sauce from being diluted and gives you better texture overall.
When it comes to thickening, the cornflour needs heat to do its job properly, so adding it at the end on HIGH makes a noticeable difference.
If the sauce still feels a little loose, simply leave the lid off for a short time at the end. It thickens quickly once the steam can escape.

Chicken texture: tender, not stringy
Chicken thighs are the better choice here. They stay soft and juicy and hold up well over the full cooking time without drying out.
Keeping the pieces on the larger side helps too. Smaller pieces tend to break apart and can turn a bit stringy by the end.
LOW heat gives you the best result. It’s gentler and gives the chicken time to become tender without overcooking. High is quicker, but it’s usually not as soft.
You can check out my guide post on cooking raw chicken in the slow cooker for great tips!

When to add the vegetables
Onion goes in at the beginning and softens right into the sauce, which helps build flavour from the base.
Capsicum is more flexible. If you like it soft, add it at the start. If you prefer a bit of bite, add it later so it stays slightly firm.
Splitting the pineapple is one of those small changes that really pays off. Some cooks into the sauce, and the rest added at the end gives you those fresh, juicy pieces.

How to finish the sauce so it tastes like takeaway
The sauce should end up glossy and lightly sticky, coating the chicken rather than sitting thin in the bottom. The sauce should coat the back of a spoon when it’s ready.
This is the moment to taste and adjust. A small splash of vinegar can lift it, or a pinch of sugar if it needs rounding out.

How to Make Slow Cooker Sweet & Sour Chicken
Step 1: Place the chicken, onion, capsicum, and half the pineapple into the slow cooker.

Step 2: Mix the sauce ingredients together and pour over, then gently stir to coat.

Step 3: Cook on LOW until the chicken is tender and the sauce has developed flavour.

Step 4: Stir through the cornflour slurry and remaining pineapple, then cook on HIGH until thickened and glossy.

Step 5: Taste and adjust if needed, then let it sit briefly before serving.

If you enjoy these takeaway-style flavours, my Slow Cooker Honey Soy Chicken has a similar rich, savoury finish, and the Slow Cooker Apricot Chicken leans a little sweeter but just as easy.
You might also like:
- Slow Cooker Whole Chicken
- Slow Cooker Butter Chicken
- Slow Cooker Chicken Noodle Soup
- Slow Cooker Creamy Lemon Chicken
Helpful Tips Before You Start
Can I use chicken breast instead?
Yes, just reduce the cooking time and keep the pieces larger so it stays tender.
Why is my sauce bland?
It usually just needs a lift at the end, a little vinegar or a pinch of salt can make a big difference.
Can I make this ahead of time?
Yes, and it often tastes even better the next day once everything has settled.
Can I skip thickening the sauce?
You can, but it won’t have that classic glossy finish.

Slow Cooker Sweet & Sour Chicken
A classic takeaway-style sweet and sour chicken made easy in the slow cooker, with a glossy, balanced sauce and tender chicken.
Ingredients
- 1 kilogram boneless skinless chicken thighs , (about 800 grams once trimmed), cut into large chunks
- 1 onion , diced
- 1 red capsicum, cut into chunks
- 1 green capsicum, cut into chunks
- 1 cup pineapple chunks, divided (drained, reserve ¼ cup juice)
Sauce
- ½ cup tomato sauce (ketchup)
- ⅓ cup brown sugar
- ¼ cup rice vinegar (or apple cider vinegar)
- 3 tablespoons soy sauce
- 2 cloves garlic, crushed
- ¼ cup reserved pineapple juice
- ¼ cup chicken stock
To finish
- 1½ tablespoons cornflour
- 2 tablespoons water
Instructions
- Place the chicken into the slow cooker.
- Add the onion and capsicum.
- Scatter over half a cup of the pineapple chunks.
- In a jug or bowl, combine the tomato sauce, brown sugar, vinegar, soy sauce, garlic, pineapple juice and chicken stock. Stir well to combine.
- Pour the sauce over the chicken and vegetables and gently mix to coat.
- Cover and cook on LOW for 4–5 hours or HIGH for 2–3 hours, until the chicken is tender.
- In a small bowl, mix the cornflour with the water to form a smooth paste.
- Turn the slow cooker to HIGH. Stir the cornflour mixture and the remaining pineapple chunks through the sauce.
- Cook for a further 15–20 minutes, uncovered if possible, until the sauce has thickened and become glossy and coats the chicken.
- Taste and adjust if needed, a little extra vinegar for tang or a pinch more sugar for sweetness.
- Serve over rice, spooning plenty of sauce over the top.
- Leftovers keep well in the fridge for up to 3 days in an airtight container. The sauce will thicken further as it sits.
- To freeze, allow to cool completely, then store in freezer-safe containers for up to 3 months. Thaw overnight in the fridge before reheating.
- Reheat gently on the stovetop or in the microwave until piping hot. Add a splash of water or chicken stock if the sauce has thickened too much, and stir well to bring it back to a glossy consistency.
Notes
- This should be glossy and lightly sticky, not watery. If needed, leave the lid off a little longer at the end to thicken further.
- Adding the vegetables later will keep them a little firmer if you prefer more texture.
- For a slightly richer, more savoury flavour, you can add 1 teaspoon extra soy sauce.
- For a sweeter, more BBQ-style variation, you can swap 1 tablespoon of the tomato sauce for hoisin.
- Taste the sauce once thickened. It should be balanced and punchy. Adjust with a splash of vinegar for tang or a pinch of sugar for sweetness if needed.
Nutrition Information:
Yield: 4 Serving Size: 1Amount Per Serving: Calories: 305Total Fat: 3gSaturated Fat: 1gUnsaturated Fat: 2gCholesterol: 34mgSodium: 873mgCarbohydrates: 56gFiber: 3gSugar: 15gProtein: 15g
This nutrition calculation for Just Slow Cooker Recipes has been automated, please use your discretion with the calculation and use your own if unsure.
Thank you so much for visiting and taking the time to try this recipe. I hope you find plenty of slow cooker inspiration here on my blog.
If you’d like to see more of my latest recipes and kitchen adventures, be sure to follow along on Pinterest.
Happy cooking!
Anna



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