Sweet and Sour Red Cabbage!

Going to try this recipe in my new 2 qt slow cooker my DIL got me for Christmas mainly because it looked easy.
4 cups red cabbage (just a small one, shredded)
1 onion, chopped
1 Apple, peeled and chopped (Granny Smith)
1/2 cup cider vinegar
1/2 cup brown sugar
1 tsp salt (Or sub)

Throw in the veggies. Mix the vinegar, sugar and salt and pour over. Stir to mix and plug it in. Low for 6 - 8 hours.

Wow! This thing went south on me. I thought the cabbage might have a smell the wife wouldn't like so I plugged in the little 2 Qt slow cooker in the carport. About noon I went into the carport and thought there was something dead out there. It took a minute to realize it was the cabbage. Nothing in it should have smelled like that but I quess the combination was a bit too much. Threw the whole thing in the garbage. Live and learn.