Angry Dark Beers

[dicko]

Hi all,

Since I have been brewing AG and more to the point, since I have reasonably mastered reproducing the same beer with AG at least twice
I find that consistently a dark beer, eg: Porters etc get a much larger Krausen in the primary fermenter than the lighter coloured beers.

I tend to brew an AG brew of 48 to 50 litres into the fermenter and all the dark beers touch the top of the lid or sometimes climb out through the fermentation lock and try to take over the fermentation fridge.

With a similar SG and quantity, and a lighter coloured grain bill then I never seem to get the same vigourous result.
I do the same procedures with lights and darks!

So, lets hear from anyone who may be able to offer an explanation as to the respective causes for this phenomenon in the dicko brewery!!

Cheers

 

[Doc]

I can't offer an explaination, but I can concur with your observations.
My dark belgians, porters, imperial porters, dunkelweizens, stouts are all prone to wanting to escape from the fermenter and frequently do.

Doc

 

[razz]

Sorry Dicko, no explanation from me. I use to agree with your theory until I made a kolsch in May this year. Climbed right out of the fermenter for about 2 days. :blink:

 

[apd]

Are you using the same yeasts in both types?

 

[timmy]

At a guess I'd say the ph of the darker wort is lower which in turn gives a more favourable evironment for the yeast.

At least its a possibilty.

 

[Kai]

Dicko, have you ever tried using acidulated malt in your lighter beers and if so do they ferment more vigorously?

 

[Hopsta]

I'd say its because the bubbles in the krausen dont pop as easy due to the viscosity of the roasted wort. Whereas a lighter wort wouldnt be as sticky so the bubbles would pop easier.

 

[MHB]

Dicko
Dark malts tend to have more of the high molecular weight protein degradation products (head building agents), than do lighter coloured malts.

As was pointed out in the wheat thread earlier today, hopping plays a major role in head building to, as darker beers tend to be more heavily hoped

Some yeast strains are right buggers, remember the Coopers yeast 10-15 years ago, I think every home brew kit came with a big stick.

MHB

 

[warrenlw63]

Can't say I've noticed Dicko.

Do notice a dirtier krausen on darker beers. Other than that I think it's like someone mentioned, maybe more yeast strain dependant. Some strains are real top-croppers and more inclined to want to climb out of the fermenter than others. :blink:

BTW This situation has always been more apparent to me when pitching larger amounts of yeast (read slurry from a previous batch) when the wort has maybe been a little on the warmer side of ideal.

If that's the case I usually pitch the wort on the slurry at 2-3 degrees lower than the actual ferment temp.

Warren -

 

[dicko]

hi Guys,

7 replies and all a feasable observation.

I tend to adjust the PH in lighter malt beers by changing the PH of the strike water.

I have never made a Kolsch but i have used a kolsch yeast in an Altbeir without the same result ( big foam).
I like to use lager yeasts in altbeirs - just a tastier beer IMO and there is no real guidlines for an Alt.
I got a good placing for an Alt last year using a 1056 yeast. (I didn't expect this)

I have not tried acidulated malt in my beers - but I will.

I tend to use Nottingham yeast or SO 4 in light and dark coloured ales from UK and Aus origin.
I like to use Kolsch or a variety of lager yeasts (wlp 800 and 830) in other varieties of dark lagers from EU,
although I use wy 2112 for US dark lagers but I have only done a couple of these.

Thanks for the replies you guys, i think I will keep more accurate notes with the yeasts and the procedures from now on.

Cheers

 

[dicko]

hi Warren,
Our posts overlapped.
I rarely pitch onto an old yeast. I generally make another starter or if it is a dry yeast I pitch to manufacturers specs.
I note your input, as I do with all the others ,and your comments are appreciated.
I have a Robust Porter that I pitched a dried Nottingham yeast onto yesterday.
Instead of pitching the recommended 46 gramms onto a 46 litre wort I only pitched 40 gramms and this time, instead of the whole lot climbing out of the fermenter and consuming my family :lol: it has at least managed to contain itself within the fermenter. so I see two conclusions.

1. I have a very happy fermentation condition with the dried yeast (rehydrated) and it is performing to its required result.
2. All my efforts at pitching liquid yeasts are in the end result, underpitched, despite my efforts to build two to three litres of a healthy starter for my beers. I really dont believe this. (or at least i dont want to)

I tend to sway towards MHB 's theory, as in hindsight, I seem to get a bigger Krausen on these darker beers and a smaller krausen on beers with lighter coloured malts.

This is an interesting observation but I will keep an open mind!!

Cheers