Topaz is a modern disease-resistant apple variety from the Czech Republic, distantly related to James Grieve. It always does well in taste tests, especially if you like a sharper-tasting apple.
Topaz is a medium or medium-large apple, although the size can vary. The skin colour is yellow, almost completely overlaid with red and crimson flush. The flesh is crisp and cream-coloured.
Like many disease-resistant varieties, Topaz has an interesting parentage. It is a cross between Vanda and Rubin, both developed in the Czech Republic in the latter part of the 20th century. Rubin is in turn a cross between Lord Lambourne and Golden Delicious, whilst one of the parents of Vanda is also Lord Lambourne. Not surprisingly therefore Topaz is reminiscent of Lord Lambourne, and its grandfather James Grieve, although it is much more crunchy and crisp than James Grieve.
Also like Lord Lambourne and James Grieve, Topaz is a good apple for the garden, being fairly easy and reliable to grow. The main horticultural problem is that the fruit size can be on the small side, so a good session thinning the fruitlets at the end of May is usually called for.
If you like the juicy sharpness of James Grieve or Lord Lambourne, but want something more crisp then Topaz is a great choice. Fans of Granny Smith may also like it.