In the 39 years I've been tasting and writing about Australian wine, the quality has soared while the prices of the cheapest drops have hardly moved. Why is it so, as a famous TV science professor once asked?

Most of the best value, inexpensive wines are made by big companies that enjoy economies of scale not available to the boutiques that make up more than 85 per cent of Australia's wineries.

Leo Buring is part of the giant Treasury Wine Estates, and riesling is Australia's best value-for-money white varietal. McWilliam's is a big company that was sold to Calabria Family Wines this year, bringing together two Riverina-based companies that already made excellent-value wines. And Killibinbin is the budget brand of the Adams family of Brothers In Arms fame, whose grapes come from their large Langhorne Creek property, Metala.

All three offer wines that deliver plenty of bang for buck.

Killibinbin Secrets Cabernet Shiraz Petit Verdot 2019, Langhorne Creek, $15

Score 92

The colour is a promising deep red-purple and there are inviting blackberry cabernet aromas with a lilt of spice and a curious but subtle patina of oyster shell, while the palate is medium- to full-bodied and intense, with bright cassis flavour, sweet and fleshy, lively and appealing throughout. The tannins are suitably firm and in harmony with the rest of the wine. Amazing value for money. Screw-cap; 14.5 per cent alcohol.

Ageing Drink now to 12 years

Stockists Doc's Liquor, Ringwood North (Vic); brothersinarms.com.au

Leo Buring Dry Riesling 2021, Clare Valley, $20

Score 95

Riesling is the go-to grape variety for anyone seeking value-for-money white wine. In outstanding vintages like 2021, even wines of modest rank can be exceptional. The discreet aroma is talcy and gently floral, with traces of lemon and lime that come through more strongly on the palate. The acidity is bracing, leaving a lemon sherbet aftertaste. A gorgeous young riesling, loaded with energy, not too dry but beautifully balanced. And great value. Screw-cap; 11.5 per cent alcohol.

Ageing Drink now to 12 years

Stockists Dan Murphy's stores

McWilliam's MCW 660 Reserve Syrah 2019, Canberra District, $25

Score 94

The colour is deep and youthful red-purple while the alluring bouquet features black fruits and subtle spices, with oak taking a back seat, allowing the fruit free expression. There's a lovely combination of intensity and elegance, a definitive shiraz with perhaps more weight and grip than expected from this region. There's a subtle sweetness at its heart, surrounded by fine savoury tannins. Outstanding value. Screw-cap; 14 per cent alcohol.

Ageing Drink now to 10 years

Stockists Liquorland & First Choice Stores, Melbourne and Sydney