If the cabbage rolls turn out sour, then the problem is most likely not in the cabbage.
The only time the ingredients are to blame is if they have gone bad. Otherwise, neither the mince nor the cabbage should be sour.
If the cabbage rolls are sour, the problem is in the sauce. It is usually made from tomato paste or sour cream, or the two ingredients are mixed.
The ingredients make the dish more sour. If the cabbage rolls make you wince every time, it's time to change the filling recipe a little.
It is enough to add a tablespoon of sugar during cooking. The ingredient will balance the filling, will become a kind of flavor enhancer and will allow you to enjoy the cabbage rolls.
In addition to sugar, you can add toasted flour to the sauce. Then the sauce will be thicker, great for stewing over low heat.
You can fix a sour dish with sugar. To fix the taste, you need to add this ingredient to the sauce after cooking.