It's JANE MacQUITTY's turn to sing the praises of Portugal's native grape varieties and its wines this week. Many bear a hefty price tag, but among the more affordable wines, she recommends: Sainsbury's 2005 Taste the Difference Douro red (6.99), produced by Quinta do Crasto; 2001 Jos de Sousa red (6.29; Waitrose); and 2004 Portal da Aguia Trincadeiro (5.69; Oddbins).