I made pancakes a couple times recently, and they had a strange reaction to some frozen raspberries we had. When we put the raspberries onto the pancakes, they had a strange fizzy and sour taste. We could still taste the sweetness of the pancake and toppings as well, but this fizz kept coming back. It was erratic, but probably due to not being evenly mixed.
The raspberries ingredient list just say that they're 100% raspberries. There were also blueberries from the same brand that didn't at all have this effect.
The pancakes contained:
- Baking soda
- Vanilla sugar
- Soy milk
We used two different recipes but it happened both times. The second time we purposefully chose a recipe with less baking soda in case that mattered but it didn't seem to make a difference.
Also I live in Ireland if the locality affects how the frozen berries might be stored.