Belgian beer turning sweet

[DonRikkles]

My last two belgian beers - a dubbel and a tripel - have turned sweet after a few months in the bottle. Almost too sweet. It's a malty sweetness, almost fruity. It doesn't resemble any noticeable off-flavor, though my palette is not as developed as others who may disagree with me.

I'm wondering why this sweetness occurs 3-4 months after bottling. The sweetness has been noticed by BJCP judges and me. The tripel turned so sweet that I had to dump the bottles after about a year and I fear my dubble (brewed in September, bottled in November of 14) is on its way to candyland. It's a shame too, because my dubbel was really fantastic around mid-January. If I had to diagnose myself, I fear that the bitterness is wearing off. My OG/FG and IBUs are below, but I don't think it's under attenuation as I'm usually under the target FG. Could it be an infection? Could it be an off-flavor? If it's the bitterness wearing off, is the solution as upping the IBUs? Please help!

Tripel:

1.085 OG
1.008 FG
24 IBU

Mostly pils with 2.5% each of Carapils and Aromatic

Dubbel:

1.071 OG
1.009 FG
23 IBU

Pils - 77%
Rye - 7%
Aromatic - 3.5%
Caramunich II - 3.5%
Speical B - 1.8%

 

[orangehero]

What's the yeast?

You could definitely bump the IBU's on the tripel to help with aging. You're on the high end of OG and low end of IBU's.

 

[DonRikkles]

Wyeast 3787 for the Tripel

WLP500 for the Dubbel

 

[DonRikkles]

Bump

 

[beerkench]

Could be infection or it's possible that oxidization is causing the hop flavour to diminish.


Sent from hell
using Home Brew

 

[beerkench]

Also If you're storing your beer at room temp, they're going to age faster.


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[GrainCounter]

Did you have late addition flavor/aroma hops? If so, it is possible that the decay of the potency of these hops over time is decreasing your perception of bitterness.

I don't see mention of simple sugar. A Tripel can easily take 20% of fermentables from simple sugar, which may help a lot.

When are you tasting the sweetness? Is it up front or does it finish sweet? A dubbel can be sweet up front as long as it finishes dry.

 

[mbbransc]

Could be infection or it's possible that oxidization is causing the hop flavour to diminish.


Sent from hell
using Home Brew

That was my guess

 

[beerkench]

Read this about oxidization from http://www.professorbeer.com/articles/oxidative_staling_beer.html
'Dark beers tend to be affected differently. As they age, rich malt aromas are replaced by sweet, sherry-like tones. Many people find this aroma enticing, although it is much different from the original malty character of the fresh beer. Most concerning, the malt flavor of the beer disappears, leaving an emptiness in the palate that can be quite disappointing.

These sherry characteristics are the result of the oxidation of malty-tasting chemicals called melanoidins. Their oxidation products have a wide range of flavors, one of which is the almond-like benzaldehyde. Together, the different compounds are responsible for the flavor of sherry.

A degree of sherry-like flavor adds complexity to certain strong beer styles, like barley wine and dark Belgian ales. It is usually not considered appropriate in lower alcohol beers, and too much oxidation will even render strong, dark beers monotonous.'

 

[DonRikkles]

I really think it could be the oxidation. A number of beers that I thought were once very good have received notes such as "slight oxidation" in a few BJCP competitions. This problem seemed to occur when I stopped using idophor and started using star san when bottling. I know I know...star san does not give any off flavors, but I can't seem to shake that correlation.

I'll have to try to isolate the weak leak in my bottling setup that allows the oxidation to occur. I can't think of a place it would happen during fermentation. The only exposure the beer has is at bottling. I've started kegging since, so it should become less of a problem (thank god for the BMBF) but I do still plan to bottle some belgians and weizens that benefit from higher carb levels and bottle conditioning.

Thanks for the help, everyone.

 

[DonRikkles]

Did you have late addition flavor/aroma hops? If so, it is possible that the decay of the potency of these hops over time is decreasing your perception of bitterness.

No, no significant aroma or flavor additions to either.

I don't see mention of simple sugar. A Tripel can easily take 20% of fermentables from simple sugar, which may help a lot.

Used candi sugar and d-90 in both beers. A pound in each, I believe.

When are you tasting the sweetness? Is it up front or does it finish sweet? A dubbel can be sweet up front as long as it finishes dry.

The tripel becomes sweet after the initial taste and gets to be cloying as the taste progresses. The double is sweet in the middle but finishes dry. Glad to know that such a progression is acceptable to the style.