Some Gravity Numbers and Questions on a Dubbel

[jalgayer]

Hi All,

I brewed a Belgian Dubbel on March 6th with an OG at 1.082.

Using the yeasts attenuation % listed on the wyeast website, I calculated that the FG should be between 1.020 and 1.025. (I know that those numbers are guidelines)

After a VIGOROUS and fast starting primary at between 69-71F (3 days or so of churning like I had thrown the carboy is a washing machine) it settled for a slower fermentation for a few days. The fermentation was likely strong due to a good yeast starter, yeast nutrients and the recipe I brewed had ~1.5# of honey at flameout.

So I take the gravity today and I am at 1.011 which is WELL under the 1.020-1.025 I was shooting for.

I am rather sure that it is done and wont go lower.

I guess I am just looking for comments, advice on this post. I am thinking that since honey is so fermentable it may have helped the attenuation... Maybe the yeast fuel helped a bit... and a nice starter and STRONG fermentation.

Thanks for any insight or comments on this.

 

[Suthrncomfrt1884]

You're correct on most of it. The honey and yeast nutrient probably helped. I try to avoid yeast nutrient if I'm making a starter because I feel it's a waste.

On a side note, your fermentation temps were a bit high for a belgian yeast and that's probably why it took off so crazily.

 

[jalgayer]

Hmmm.... The Northern Brewer web site said that optimum temps for the 1214 belgian abbey yeast was 68-78F. And I just check wyeasts website and they have the same listed temp ranges. I was probably at 71 for the most of the time. There was definitely a period of 74 or so when the fermentation really took off.

If those temps are not the right ones to ferment at... How do I know what to do if the kit and the website are both wrong?

Thanks for pointing me towards what to do... I have a few batches coming up and dont want to go at the wrong temps

Thanks All!

 

[sonetlumiere85]

Nothing at all wrong with those fermentation temps. Most Belgian yeasts prefer warmer temperatures, though they'll work at lower ones as well. However, you won't get as much ester and phenol production with lower temperatures. Sounds like you made a great dubbel!

The thing with attenuation is that there's apparent attenuation, and actual attenuation. Alcohol production influences gravity readings and makes it tricky to get the actual attenutation. In this case, your apparent attenuation would be 85.8%, and actual 70.3%

 

[jmansfield]

So this is going to be quite dry compared to your target. You were expecting 7.7 BRIX (%sugar, sweetness) and 7.9 % ABV but you ended up getting 5.6 BRIX and 9.2 %ABV.

For Belgian yeast I try to start out around 70 F but then walk down to 67-68 an monitor to make sure it doesn't fade, makes for cleaner taste and likely would have tempered your attenuation some. Let us know how it tastes,

 

[jalgayer]

When you are talking about temps... You are talking about the actual temps of the wort, correct? Not the ambient temp?

 

[fenixwb]

When you are talking about temps... You are talking about the actual temps of the wort, correct? Not the ambient temp?

Yes. Jmansfield is correct if you're looking for a cleaner profile. Me, personally, I prefer a more funky Belgian flavor. I usually start my Belgians at around 68 and keep them there for the first three days, and then let them slowly rise up to 72-75 depending on what I'm going for and the strain I'm using. This minimizes the hot phenol alcohols that develop at the beginning of fermentation if temp is too high, but still allows the fruity esters to develop in the mid to late fermentation.

I do want to reiterate that there's nothing wrong with the temps you fermented at. In fact temperature is one of the best way to really mess around with the flavor profile of a Belgian because the yeast have such a large range and their output can change dramatically with just a few degrees difference.

The book "Brew Like A Monk" has a great chart detailing the various flavors made by all the major Belgian strains at different temperatures. That book in general makes a great resource if you're planning on doing a lot of Belgians.

 

[Suthrncomfrt1884]

Just to be clear...your temps weren't too high for belgians, but belgians are fermented a bit differently. As a few people above have mentioned, they don't stay at the same temps. Personally, I don't like as many esters, so I start around 65F for the first few days and then slowly raise the temp by 1-2 degrees a day until I hit about 74F. I don't like letting my belgians go higher than that.

 

[permo]

your beer is PERFECT....higher fermentation temps for belgians give them their flavor and encourage major attenuation. Good job! You have a great beer. I crank my belgians, using the Chimay strain, up near 80 at the end of fermentation. You are brewing a belgian beer and the highlight of said style is the flavor from the yeast...start it low and ramp it up over time to encourage attenuation and flavor...you did it right, although the honey may give a few out of style aromatic qualities...but it fermented out for sure

One of the sneaky secrets as to why the monks brew such pallatable and potent, "sneaky" brews is there high attenuation......ramping up temps and feeding sugar to the fermenter....light bodied, highly attenuated beers....good stuff.

Pesonally I would be way more concerned if my dubbel ended up over 1.020>!

 

[pompeiisneaks]

Odd, I did a dubbel a while back trying to be as close to chimay as possible, and it was too dry. The sweetness comes from less attenuation, i.e. around 1.020... The more attenuation you get the more "dry" the beer is, which equates to less sugar in the final beer. maybe I'm smoking something, but that's what I always understood. Basically, though, the attenuation also depends on mash temps. I.e. did you mash at 149 or 159? higher mash temps give less fermentable sugars adn therefore lowers attenuation, and gives a more malty/sweet beer.

 

[permo]

Odd, I did a dubbel a while back trying to be as close to chimay as possible, and it was too dry. The sweetness comes from less attenuation, i.e. around 1.020... The more attenuation you get the more "dry" the beer is, which equates to less sugar in the final beer. maybe I'm smoking something, but that's what I always understood. Basically, though, the attenuation also depends on mash temps. I.e. did you mash at 149 or 159? higher mash temps give less fermentable sugars adn therefore lowers attenuation, and gives a more malty/sweet beer.

You are correct about the higher the FG the more sugars left in the beer, 1.020 is a little high for a chimay red/white clone to finish, maybe on point for a blue though. IMO. I haven't had a chimay in a while, but there is a nice sweetness to them, but they are light bodied too...I would bet it is a lack of hop bitterness that helps the percieved sweetness as well...not just unfermentables.