[charles1968]

^^^^
Reports I've read give the following schedule for Duvel:  6 days primary warm fermentation in split batch with 2 different strains followed by blending and 3 days secondary at cold temperature; 4 weeks cold conditioning;   filter, dose with one of the 2 strains and prime, held two weeks to carbonate before release.

Is that direct from Duvel or a secondary source? Their website says 90 days.

http://www.duvel.com/en/the-beer/duvel

"Thanks to the addition of extra sugars and yeast, the beer ferments again in the bottle. This occurs in warm cellars (24°C) and takes two weeks. Then the beer is moved to cold cellars, where it continues to mature and stabilise for a further six weeks. This extra long maturation period is unique and contributes to the refined flavour and pure taste of Duvel."

[Robert]

^^^^

That was secondary sources, but more than one, and what's interesting is the website info  is consistent with that, except that they say they hold it an extra 6 weeks after the 2 week bottle fermentation.  Other sources say it's released right away.  Maybe there are different practices in use for different markets?  Or somebody's just trying to throw us off the scent of trade secrets?

[majorvices]

Duvel is a great beer, I really like it. I could make a clone of that beer that would be pretty great too and wouldn't need 90 days. They may have other reasons for aging that long (if it is true, it may just be marketing) but I'm sure it isn't because they are having to age out off flavors from fermentation.

[Robert]

My money's on they don't age it, it's just marketing.  Like "We know of no other beer that costs so much to brew and age" or however that goes.  Mystique.

[charles1968]

Speaking as someone who always bottle conditions and never kegs, I can see the benefit of 6 weeks cold cellaring. The beer will be crystal clear and smooth after storage. Not necessary if you fine, cold cash and keg. I don't think it's marketing hype.

A lot of Belgian beers sold in the UK and Europe are bottle conditioned. To my mind, "fresh" is when these beers have finished secondary fermentation & lagering in the bottle, not at the point of packaging. After that, I agree they deteriorate over time.

[Robert]

But Duvel is lagered at -2°C for 4 weeks and then filtered before dosage, so 6 weeks in bottle are not required for clarification or flavor maturation.

[charles1968]

Bottle conditioned Duvel isn't filtered, I think you're confusing draft Duvel with bottled. As for flavor maturation, I would say the jury's out on that one. As long as the yeast are alive and metabolizing, they might well be altering the flavor. However, I've yet to see a brulosophy-style experiment testing the effect of conditioning beer on live yeast vs taking beer off the yeast and kegging, so I'm loath to form a rigid opinion. In my anecdotal experience, maturing certain beers improves them significantly, though a lot of that is about carbonation, clarity and attenuation.

[majorvices]

Speaking as someone who always bottle conditions and never kegs, I can see the benefit of 6 weeks cold cellaring. The beer will be crystal clear and smooth after storage. Not necessary if you fine, cold cash and keg. I don't think it's marketing hype.

A lot of Belgian beers sold in the UK and Europe are bottle conditioned. To my mind, "fresh" is when these beers have finished secondary fermentation & lagering in the bottle, not at the point of packaging. After that, I agree they deteriorate over time.

But that's not the same thing as aging out off flavors ... as was mentioned.

[Robert]

Most all bottle conditioned beers are filtered and dosed with a preferred yeast for bottle fermentation.  For that matter, the usual practice is to have the beer carbonated to within 0.2v/v of target so that there is minimal fermentation in bottle, just to finish carbonation and provide some live yeast in the bottle to allow, but not require, ageing. Information I have seen indicates that this is the case with Duvel, but maybe not.  At any rate, the goal in modern bottle conditioning practice is to minimize impact of the bottle fermentation on beer character.

[charles1968]

Speaking as someone who always bottle conditions and never kegs, I can see the benefit of 6 weeks cold cellaring. The beer will be crystal clear and smooth after storage. Not necessary if you fine, cold cash and keg. I don't think it's marketing hype.

A lot of Belgian beers sold in the UK and Europe are bottle conditioned. To my mind, "fresh" is when these beers have finished secondary fermentation & lagering in the bottle, not at the point of packaging. After that, I agree they deteriorate over time.

But that's not the same thing as aging out off flavors ... as was mentioned.

Yes the question is whether Matty can rescue his beer with ageing and I think it's worth a go. But as I haven't tastes it, I can only guess what the issue is. If it's infected, it's a hopeless case. If it's just green, there's no harm in waiting.

[charles1968]

Most all bottle conditioned beers are filtered and dosed with a preferred yeast for bottle fermentation.  For that matter, the usual practice is to have the beer carbonated to within 0.2v/v of target so that there is minimal fermentation in bottle, just to finish carbonation and provide some live yeast in the bottle to allow, but not require, ageing. Information I have seen indicates that this is the case with Duvel, but maybe not.  At any rate, the goal in modern bottle conditioning practice is to mobile the impact of the bottle fermentation on beer character.

Bottled Duvel is definitely unfiltered. Their website is very clear on that. Whether you believe their claims about the second fermentation & maturation altering flavour is another matter...

[majorvices]

Speaking as someone who always bottle conditions and never kegs, I can see the benefit of 6 weeks cold cellaring. The beer will be crystal clear and smooth after storage. Not necessary if you fine, cold cash and keg. I don't think it's marketing hype.

A lot of Belgian beers sold in the UK and Europe are bottle conditioned. To my mind, "fresh" is when these beers have finished secondary fermentation & lagering in the bottle, not at the point of packaging. After that, I agree they deteriorate over time.

But that's not the same thing as aging out off flavors ... as was mentioned.

Yes the question is whether Matty can rescue his beer with ageing and I think it's worth a go. But as I haven't tastes it, I can only guess what the issue is. If it's infected, it's a hopeless case. If it's just green, there's no harm in waiting.

Agree, I did advise him to try aging it out as well. It's always worth a shot.

[Robert]

Most all bottle conditioned beers are filtered and dosed with a preferred yeast for bottle fermentation.  For that matter, the usual practice is to have the beer carbonated to within 0.2v/v of target so that there is minimal fermentation in bottle, just to finish carbonation and provide some live yeast in the bottle to allow, but not require, ageing. Information I have seen indicates that this is the case with Duvel, but maybe not.  At any rate, the goal in modern bottle conditioning practice is to mobile the impact of the bottle fermentation on beer character.

Bottled Duvel is definitely unfiltered. Their website is very clear on that. Whether you believe their claims about the second fermentation & maturation altering flavour is another matter...

I can't find any statement on the website that it is unfiltered.  They do state that it is dosed, which requires removal of the original yeast.  You can find many textbooks and articles that detail bottle conditioning practices; you can start with DeClerck if you like, the very man who isolated the yeast and developed the recipe for Duvel.  Marketing is not meant to be a technical guide.

Note that what homebrewers call bottle conditioning, and can work well for us, is a very different thing from what is necessarily practiced in commercial brewing.  Matty, let it age and bottle it!

[klickitat jim]

Have I posted to this debate yet?

[Robert]

Have I posted to this debate yet?

Well I guess you have now.