The taste which we can detect already at very small concentrations is salty taste.
The reason why we have a special affinity for tasting bitter things. The reason why we can taste bitter things at extremely low concentrations is because potentially dangerous compounds can be bitter and it made evolutionary sense for organisms to adapt to taste bitter things.
People have very strong negative reactions when it comes to a bitter taste. Most of the substances like toxins have bitter taste. The ability of the taste buds to taste the bitter substances shows evolutionary history. The taste has evolved because most of the substances that are harmful to the human beings are bitter in taste. The substances such as alkaloids, drugs, medicines, quinine, caffeine and nicotine have bitter taste. These tastes are not very common to the taste buds so they are detected at very low concentrations.
