Bodegas Toro Albalá is arguably the best producer of Pedro Ximenez in the world today. Founded in 1844, though the modern incarnation is better dated at 1922, it's a remarkable operation. Their wine library located in their tasting room comprises more than 100,000 reference books!
They have a barrel room that's the envy of many, with consecutive vintages dating back to the time of WW2 and even earlier that, patiently ageing in predominantly old American oak barrels until their release, years decade or even half a century later. The winery has in recent years by having made the only dessert wine to have achieved a 100/100 score by Parker in Wine Advocate for their 1946 Don PX Convento and has seen a spark in interest for their very limited produce.
During the slow barrel maturation which allows controlled exposure to oxygen, the wines undertake a delicious, savoury, rancio transformation which brings on a nutty, iodine character that takes complexity to the next level, whilst maintaining a certain freshness. With more and more time in barrel the wines concentrate in both flavour and texture and the colour develops in to a viscous, dark almost motor-oil thickness - a wonderful mouthfeel indeed.