Old Forester 1910 Old Fine Whisky is a historical first and a historical last: the final bottle of the Whiskey Row series, and a totally new kind of bourbon for the brand.

This newest (and apparently final) Whiskey Row bottle “1910 Old Fine Whisky” pays homage to a happy distilling accident back in, well, the year 1910.

Faced with a fire that October, the distillery’s bottling line was shut down and they had vatted whiskey that needed to go somewhere. That vat ended up in new, charred oak barrels for a second time, and stayed there until the bottling line could be repaired. Brown-Forman claims the resulting “Old Forester Very Old Fine Whisky” is the first documented double barreled whiskey.

Old Forester didn’t just throw this new whiskey into regular charred barrels for a quick finish though: they created a whole new barrel type.

“This is really cool because this is the first time we’ve actually ever released an Old Forester that has a finishing on it,” said Master Taster Jackie Zykan. She explained that Old Forester 1910 is quite different from Woodford Double Oaked. “[With Double Oaked] They take Woodford, put it in a second barrel that’s been heavy, heavy toasted. So Woodford Double Oaked is butterscotchy, creamy vanilla–like super sweet. This one’s a little bit different. We put it in a barrel that’s been charred to the point where it’s going to fall apart,” she explains, “So there’s so many more undertones of that smoky charry flavor.”

And it’ll have a different profile from typical double barreled whiskeys because of the extra charring. “Because you’re putting a double oak influence on it,” says Zykan, “it’s definitely got a heavy vanilla punch on it, but because of the heavy char it’s so chocolatey, like chocolate syrup in a bottle.”

So exactly how much char is too much? It has to do with char time at the Brown-Forman Cooperage. “The standard Old Forester barrel gets about a 22 second char on it,” says Zykan, but this second 1910 barrel gets more than double that. She says it actually exceeds the 50 second mark. “So it is like cooked,” she explains. “The barrel is charred, charred, charred. We took it up as high as we could before it wasn’t going to be viable to hold liquid anymore.”

Once regular, 4-year-old Old Forester bourbon is put into one of these finishing barrels (at 100 proof), it stays there for between six and nine months for finishing before it becomes 1910.

At 93 proof, Old Forester 1910 is definitely in at the right weight to challenge another Whiskey Row Series bottle for supremacy. Popular opinion says that it’s currently Prohibition 1920 that is the favorite from the series–and maybe the entire Old Forester portfolio.

Zykan thinks that’s about to change.

“I know 1920 was everybody’s little darling for the last year or so,” she acknowledges. “Every single lineup I’ve had where I’ve tasted people on the 1910… It’s like the 1920-II. [They’re saying] this is incredible this is hands down one of the best Old Forester products I’ve ever tasted.”

Old Forester 1910 Old Fine Whisky is available later this month at a suggested MSRP of $55.