Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Spoils the food and leaves a bad taste for a long time

This product tastes very bitter (which is a good thing) but the taste doesn't go away for hours. The first time my daughter sucked on her thumb (after I applied Mavala) she was crying and spitting the whole night. I tried it too and I had a bad taste the whole night. And if my daughter dips her thumb in milk or water or any other food the whole thing gets bitter and can't be eaten. Not very happy with the product.