It's been a challenging week with Tuesday and Wednesday devoted to tasting red blends for Wine magazine, in between my tannin-battered palate was relieved by a most enjoyable nine-vintage vertical of Iona's well-respected sauvignon blanc.

As I anticipated, the red blends proved a difficult task, not only because of numbers - around 150 all told, including a re-taste of the top scorers to ensure we hadn't under-scored in the first round - but also, and which complicated the exercise, through lack of distinction. The wines were divided into three categories; those with a minimum of 30% shiraz, Rhône style and a miscellaneous group that don’t fit into either of the above two, Bordeaux-style or blends with pinotage. You will understand the first and especially the last proved real hotch-potch selections, even if they did include some high-profile bottlings. In both it was incredibly difficult to pick out the pearls from the pack.

High and unbalanced alcohol remains one of the major problems, as - sadly still - does over-generous oak. Apart from the tiring and unpleasant effect these have on drinking one wine let alone tasting a whole line up, they diminish any nuance of flavour there might be. Not surprisingly, several were already on their last legs, even though the oldest wine was a 2004.

In welcome contrast, not one of the Iona sauvignons (2009 to 2001) shows any sign of tiredness, even the 2001 still has evident fruit richness. (In the photo, Rozi Gunn, co-owner with husband, Andrew discusses the wine.)

Analyses are all excellent with low pH levels, high natural acids, moderate alcohols and all are bone dry. Despite a new Elgin site now providing fruit from a variety of clones, which has taken production from the initial 1200 to the present 11 500 cases, there is a clear house style: purity with restraint. It was interesting to note the nine wines were closed with a mix of cork and screwcap but such was their consistency, it would have been very difficult to say which wine was closed with which closure.

The following morning it was back to red blends, finishing with the Rhône style. The difference between these and the other two categories was marked; more diversity of flavour, texture and interest, even with generous alcohol. Whereas we struggled to find four star wines in the other categories, we just fell short of a five star in the Rhône style, with two achieving four and a half stars.

Various thoughts occurred to me after this experience: above all, don't underestimate the benefit of matching variety to site; that said, Rhône style blends, which include later ripening varieties, show much promise; adding acid might achieve better balance, but doesn't restore flavour that has dissipated from grapes harvested when the tannins are ripe but acids have dropped and sugars have soared.

One red where the vines are clearly well-matched to site allowing the grapes to achieve optimum ripeness with flavour and freshness is Rust en Vrede Cabernet Sauvignon 2007, which topped all the entries at this year's Diners Club Winemaker of the Year Award, winning winemaker, Coenie Snyman a generous cheque and ticket to any wine producing area of the world he chooses. Diners Club CEO Linda Mazini is seen in the photo presenting Snyman with his grandly framed certificate.

The wine is in modern classic style with pure, fresh fruit and crunchy tannins from a really good vintage. At around R135, it's not over-priced. It's good to see this Helderberg property once again taking major awards after the dip it went through a few years ago.