If you were considering placing a bid on a bottle of Penfolds Grange estimated to be worth more than $50,000, senior winemaker Stephanie Dutton is the person you might want to speak with first.

As an integral member of the winemaking team that produced the wine, Dutton has tasted the 2016 vintage of Grange – Penfolds’ most recent release – on many occasions, and says it a particularly good year that taps into Penfolds’ house style.

“It was full of mid-palate sweetness, structurally firm and age-worthy tannins, which means when it comes to making and crafting an age-worthy wine, a lot of things lined up in 2016,” says Dutton.

With a price guide of $50,000 to $60,000, the six-litre imperial of Penfolds Bin 95 Grange 2016 will be auctioned through the biennial Barossa Wine Auction on Friday, April 16.

“We are very keen to see who the lucky recipient will be and what the fate will be for this bottle in the years to come,” says Dutton.

“You are guaranteed that there will always be ceremony and an occasion that is marked when it does finally get opened.

“There’s a true collectability, scarcity and rarity that’s wrapped up in a piece like a six-litre imperial of Grange. It’s something that is hard to find anywhere else apart from in our museum at Penfolds.”

Each year, Penfolds produces a small number of Imperial bottles of Grange, which are kept in the Penfolds museum at Magill Estate.

Of the 2016 vintage, only 11 imperial bottles exist.

The Grange imperial has been the flagship lot of the biennial Barossa Wine Auction for the past two decades.

A record for auction was set in 2003, when the 1998 Grange vintage sold for $64,000.

This year is Penfolds’ 70th unbroken line of Grange vintages since it was first produced in 1951.

Although a standard-sized 750mL bottle of 2016 Grange sells for a relative fraction of the cost at $950, the imperial bottle is highly sought after by collectors because of its superior longevity.

“Anything that you capture in a bottle like this, there’s a very high chance that will last beyond your lifetime,” says Dutton.

“So, you always want to make sure that what you’re capturing is something that’s going to do the next generation of winemakers proud. It’s a big responsibility.

“In terms of the quality and whether that will appreciate over time, the answer is yes, absolutely.”

The bottle’s exponentially greater lifetime is due to its large wine volume compared to a relatively small surface area exposed to oxygen beneath the cork.

Dutton says the true life span of such a bottle is yet to be determined accurately, given that it may very well last beyond 70 years – longer than Penfolds has been producing Grange.

A normal-sized bottle of Grange is conservatively estimated to have a 30-year lifespan but exceptional vintages can age more than 50 years.

Every time you double a bottle size, longevity is increased.

“Once you start to do the math, although the science is hard to pin down with exact authority, all of a sudden you’re looking at something that has a life expectancy that’s still to be determined,” Dutton says.

“It’s beyond a lifetime of age-worthiness that’s very hard to quantify.

“Given the first vintage was in 51, I don’t think we’ve really tapped into exactly how far it can go. It’s beyond a lifetime of age-worthiness.

“These are bottles that can quite literally outlive you.”

This year’s Barossa Wine Auction has expanded to include an additional live auction in Sydney, as well as a separate online auction.

The bidding will be carried out by Langton’s Fine Wine Auction House, which has been involved since 2015 when Langton’s expanded the event to wine collectors around the world.

The event sees wine collectors bid for rare and distinguished lots sourced directly from the wineries and winemakers’ own collections.

The auction coincides with the Barossa Vintage Festival, being held from April 14 to 18, and a share of the net proceeds will be donated to the Barossa Grape & Wine Association’s well-being fund and the festival.

Other highly-collectible items to be auctioned include an 18-Litre bottle of 2018 Ron Thorn Single Vineyard Shiraz at $4000 to $5000 and a six-litre imperial bottle of Torbreck RunRig Shiraz Viognier 2017 at $3000 to $4000.

“It is always exciting to see the results of the auction, not just from a Penfolds’ perspective, but from a Barossa point of view,” Dutton says.

“There are so many beautiful rare lots that appear for this auction, it’s hard not to be proud of the entire region as a collective.”