'I'm always being asked the question about how well wines age under screw cap," says Matt Patterson-Green, winemaker for Jackson Estate in Marlborough.
"I'll tell you that I reckon it's more of a 'linear' effect under screw cap, as opposed to the humps and hollows of ageing under cork."
Humps and hollows, peaks and troughs - that's how the different stages of ageing and quality for a wine are often described. Phrases like "Aw, she's in a bit of a dip right now," or "This wine is on the upward stretch of the bell curve", are not unusual in this business.
Popular opinion is pretty much unanimous that screw caps have, since their surge in popularity in the early 2000s, singlehandedly saved New Zealand's sauvignon blanc industry. There's no question they protect and preserve those lipsmacking lime, passionfruit and herbaceous characters we love - but for how long? I've always been in the "unless it's been barrel fermented don't keep sauvignon blanc for longer than two years, drink it while it's young and crunchy" camp.
So my taste buds began doing backflips when, at the Jackson Estate 25th birthday celebrations earlier this month, Matt brought out two bottles of their sauvignon blanc, both from the same 2002 vintage, one with a cork seal and one a screw cap. "Back then we were hugely curious about screw caps and all the benefits they had to offer - so we bottled half a tank of sav under cork, the other under screw cap - and here are our oldest results. Tell us what you think please."