Rich in colour, with good acidity and rarely an excess of alcohol, Trincadeira (as it's known in the Alentejo) or Tinta Amarela (if you are speaking to a Douro producer) makes wines of serious quality when ripe, but it does not always achieve ripeness.
Properly ripened, it has vibrant raspberry fruit tempered by herby, peppery, spicy, floral complexity, and it can age well. Under-ripe, it tastes herbaceous. It is a difficult vine to grow, producing exuberant amounts of foliage and needing constant trimming to prevent those vegetal flavours. Yields are generally high, but unreliable. It is very sensitive to rot and other vineyard diseases. For this reason it does better in hot, dry places, and is therefore particularly at home in the Alentejo and Ribatejo/Tejo areas: these are the regions where it really shines. But it is grown througout Portugal.