Belgian Imperial Stout - not tasting great, hoping for helpful feedback

So I brewed this pretty big "Belgian" Imperial Stout several months ago. Close to 6 months now.

Here's the recipe:

http://hopville.com/recipe/1059534/russian-imperial-stout-recipes/belgian-imperial-stout

The body is thinner than I'd prefer, not as viscous as I was hoping. I mashed at 156 (if i recall correctly...my detailed notes are at home. But it was either 156 or 158). Boil for 90 minutes. Chilled to and fermented at 65F.

After almost 6 months, it's not tasting any better. The aroma is predominantly banana bread, and doughy bananas - best way of describing it. The taste is harsh and hot. I'm not getting any mellow roast/chocolate or any of that nice prune/raisin/plum dark fruit flavor or aroma.

This is a pretty big let down, but in order not repeat the same mistake I'm looking for some feedback on what I might have done wrong, and how I can make this better next time around.

Thoughts?

Thanks guys,
Julian

edit: I will say that the unfermented wort tasted AMAZING. Best wort I've ever tasted. It was sweet, chocolately, and luscious. None of that is present in the final product.

Sounds like it was fermented too hot.

Let the yeast get too warm and banana is what you get.

Well I kept it at 65F the whole time, although it was a VIOLENT fermentation with an incredible amount of blow off. I tape my probe to the side of the carboy. Clearly, this isn't actually reporting the right temp if this is what happened. Do you have a better way to get more of an accurate temp during fermentation? Is a thermowell more accurate at reading actual fermentation temps? Any other suggestions?

65 F ambient (room) temp doesn't guarantee inside of the fermenter is 65. It can be 15 degrees higher, especially in a violent fermentation.

You have to cool the fermenter further, especially in the summer, with a swamp cooler or a cool basement floor.

All my carboys are in my fermentation chamber (chest freezer with dual stage temp controller. ceramic space heater on the inside). If the probe reads above 65F it clicks on and cools it down by turning on the chest freezer.

But...from what you're saying, I might benefit from a thermowell to measure the internal temp, as opposed to the outside of the fermentor. Is this what you're saying?

I think I'm going to agree with you that it got too hot internally, which has been an issue for a few big brews of mine. I'm just not quite sure how to measure the internal temp, and have my chest freezer kick on in time if it gets past the set point of the controller. How do you do it? thermowell, or do you just see fermentation beginning and crank the temp down by 10-15 degrees in anticipation?

does indeed sound like you might have let things get too hot in there - fusels & esters. belgians stouts are tricky, you want some contribution of the belgian yeast but not so much as to take over. certainly don't want that train to run away on you.

julian81 said:

Is a thermowell more accurate at reading actual fermentation temps?

Click to expand...

yup, get thee a thermowell.

sweetcell said:

does indeed sound like you might have let things get too hot in there - fusels & esters. belgians stouts are tricky, you want some contribution of the belgian yeast but not so much as to take over. certainly don't want that train to run away on you.


yup, get thee a thermowell.

Click to expand...

OK thanks for the feedback. Yeah it does sound like fusels and esters for sure. This is the THIRD big beer I've done even with temperature control and I'm just shocked that others (local homebrewers) don't have these issues but I do...

I'm very curious how these recipes would turn out if I was using a thermowell.

Do you think the probe from a Ranco dual stage controller will fit down the thermowell?

I would just get it colder to begin with. Get it down to 60 and maybe set the system to 60F. You sure have a nicer chamber than I do, you should be able to make it work.

Better to be too cool and then let it warm up a little.

Once a fermentation becomes "vigorous" it makes its own heat and is difficult to cool it down. you have to start cool and keep it there.

I have found that after a year stored warm, bananna goes away.

cheezydemon3 said:

I would just get it colder to begin with. Get it down to 60 and maybe set the system to 60F. You sure have a nicer chamber than I do, you should be able to make it work.

Better to be too cool and then let it warm up a little.

Once a fermentation becomes "vigorous" it makes its own heat and is difficult to cool it down. you have to start cool and keep it there.

I have found that after a year stored warm, bananna goes away.

Click to expand...

Hrm, well I believe I started at 65 for these. If I went down 5 degrees to begin with, you're saying that would make all the difference? Hrm...I'm going to get a thermowell and check the temp from inside and see how that goes...or maybe do a combo of both.

As for the banana - that's not even that bad, it's definitely weird in a stout, but it's not *terrible*. The bad part is the fusels, and harshness. It's just not very palatable. I've tried aging that out for 6 months in the past and it just does not go away.

I'm thinking this stout is going to be an incredibly expensive stew base

Curious: I tape the probe to my glass fermentor as well and insulate it with about 6-10 layers worth of folded dish towel. What kind of insulation do you have over your probe?

bigbeergeek said:

Curious: I tape the probe to my glass fermentor as well and insulate it with about 6-10 layers worth of folded dish towel. What kind of insulation do you have over your probe?

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I usually do a couple layers of small bubble, bubble wrap or a paper towel folded over several times, taped over the probe. I'm not sure my problem is an insulation problem to be honest...

julian81 said:

I usually do a couple layers of small bubble, bubble wrap or a paper towel folded over several times, taped over the probe. I'm not sure my problem is an insulation problem to be honest...

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It very well could be. A few layers of paper towel aren't going to insulate very well -- you might be regulating ambient temperature and not beer temperature. A lot of people have success with beers big and small using the probe-on-the-carboy wall technique, myself included. I've made imperial stouts and belgian dark strongs (among many other beers) using this technique without fusels.

bigbeergeek said:

It very well could be. A few layers of paper towel aren't going to insulate very well -- you might be regulating ambient temperature and not beer temperature. A lot of people have success with beers big and small using the probe-on-the-carboy wall technique, myself included. I've made imperial stouts and belgian dark strongs (among many other beers) using this technique without fusels.

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Hrm...ok, I'll see about modifying my "tape the probe to carboy" technique. Although if that doesn't work, I'm out another expensive batch of beer

I'm just thinking that in commercial breweries the probe is in the fermentor and being monitored electronically, which kicks on the glycol...but that probe is IN the wort...so by that logic, I'd get a much more accurate read if I was using a thermowell...

I've seen other threads talk about using this:

http://www.brewershardware.com/16-Stainless-Steel-Thermowell.html

Cheaper than wasting a $50+ batch of big beer...

Another way to pull out esters and fusels is an underpitch... What was the OG , batch size and starter size? Do you hit with O2?

ne0t0ky0 said:

Another way to pull out esters and fusels is an underpitch... What was the OG , batch size and starter size? Do you hit with O2?

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The OG was 1.096
5.5 gallon batch
Starter size was 2.5L
Hit it with O2 for about 2 mins before pitching

julian81 said:

The OG was 1.096
5.5 gallon batch
Starter size was 2.5L
Hit it with O2 for about 2 mins before pitching

Click to expand...

I actually overpitched my last strong beer (6G of 1.100); I did a 2 packs into a 2L and stepped that again with a second 2L; threw about 600B yeast at it to keep the esters at bay..

mrmalty says you need about 356B yeast, which you can get with pitching two packs into 1.3L of starter... or (via yeastcalc.com which is easier to use IMO) if you pitched only 1 pack (100B) you'd need about 2.75/3L to break the 356B yeast.

All the above numbers assuming stir-plate method for starters.

From what I've read hefe and belgians yeast actually produces more esters when under-pitched. Sounds like it fermented out way to fast though like the guys have been saying. It's hard because belgian yeast is so fricken strong but you might think about adding some malto-dextrin to it if it isn't carbonated yet, or just letting it age for a while and see what flavors blend out. *shruggs* you live you learn

+1 on the thermowell Julian, it's all I run nowadays, and it's much more accurate.

I'm still waiting on that Chamomile Wit recipe by the way.

Looking at the recipe it might be a little light on bitterness...but it will definitely be a desert beer and maybe one of your best ones to date...but I am's drunk.