This can happen when the silicone takes on the residue from a meal or a dish soap that contains essential oils, antibacterial agents or moisturisers. These oils can sometimes stick to the silicone material and cause an unpleasant soapy smell of taste. Silicone itself cannot absorb flavours or give out a chemical taste. To remove the oil you can try a bi-carb or white vinegar soak overnight, even wiping your bowl out with some lemon juice. You can also boil your silicone bowl to clean it.