Big beer, aeration, and yeast pitch questions

[BoitAHL]

Hello,

I am making a 3rd attempt this weekend at brewing an Imprint Beer Co. Black Forest Cake Stout Clone. Here is a link to my previous post.

High ABV Stout Clone

My 2 previous attempts had a couple issues. Although the beer turned out very tasty, it got nowhere near the expected FG and was a bit sweet. Also, even though I was using a blowoff tube both fermentations blew (see same post link). I have a couple ideas to run by you.

1. For the FG issue I have purchased an O2 Aeration Kit. Have not used one previously. Hoping better oxidation will help the yeast. Also, I am planning to aerate and pitch half the yeast on brew day then aerate and pitch the 2nd half 24 hours later. Concerning O2 aeration, I have read many opinions on how long to aerate and need advice.

2. For the blowout issue I am planning to ferment in two separate 6-gallon fermenters at 2.5 gallons of wort each. I cannot control room temperature much but with the heat off it will be in the low to mid 60's. Hoping this will prevent the blowout.

Any advice or alternate ideas you could give will be greatly appreciated.

Thanks.

Steve

 

[VikeMan]

My 2 previous attempts had a couple issues. Although the beer turned out very tasty, it got nowhere near the expected FG and was a bit sweet.

Are you sure your expected FG was reasonable for your recipe and yeast strain? Where did you get the FG expectation from?

1. For the FG issue I have purchased an O2 Aeration Kit. Have not used one previously. Hoping better oxidation will help the yeast.

With pure O2, and assuming a flow of about 1 liter per minute through a 0.5 micron stone, I'd give 5 gallons of this recipe's wort about two minutes.

Also, I am planning to aerate and pitch half the yeast on brew day then aerate and pitch the 2nd half 24 hours later.

Why? I can't think of any reason to do that.

2. For the blowout issue I am planning to ferment in two separate 6-gallon fermenters at 2.5 gallons of wort each. I cannot control room temperature much but with the heat off it will be in the low to mid 60's. Hoping this will prevent the blowout.

That would do it, but that's really a lot of headspace. Can you put a wet T-shirt around the fermenter? Evaporative cooling. Or put the fermenter in a tub of cold water, adding ice as needed. Or add Fermcap the fermenter.

 

[hotbeer]

As for your previous FG issue, I didn't see where you mentioned in the other thread if you had any mash temp issues? If you didn't have too good a temp control and homogenous throughout the grain then you might have made too many unfermentable sugars.

And not withstanding that I just tend to find most stouts on the sweet side. However I do like them for the other flavors they bring.

For you issue of mess when it krausens, I can only add that I haven't had a mess with any since I switched from small diameter blow off tubes to a blow off tube that fits the hole without a stopper. And to my knowledge the krausens are just as active. I'm sort of thinking maybe with the pressure inside staying more normal, the bubbles get bigger quicker and break their surface tension. So not as much foaming to the top of the fermenter and beyond.

 

[GrowleyMonster]

A high mash temp could cause your FG to be high. Or cold ferment temp near the end. I doubt that oxygenation is an issue. I just pour the wort into the fermenter from high enough up and that seems to be plenty of aeration, and right before pitching, so exactly the right time.

 

[VikeMan]

A high mash temp could cause your FG to be high.

It could, but @BoitAHL didn't do a mash.

 

[BoitAHL]

All,

Thanks for the advice so far. Just an FYI for those who mentioned mash temp this is an extract recipe with specialty grains so would mash temp = steeping temp?

VikeMan- The recipe came from BYO. For the FG I am assuming the creator knows more about building and calculating a beer recipe than I do (which is none). Also, FYI I am using 4 packs of rehydrated Mangrove Jack's M42 yeast. As for the yeast and oxidation staging I have seen several articles/forum posts that recommend this including advice from someone at Midwest Supplies. I agree that using 2 fermenters there would be a lot of head space but I do not plan to open them after the second pitch until I know fermentation is done. Again, I have seen articles/posts where brewers do not have any issues. Lastly, would using a tub with water/ice be hard to control the temp and create the possibility of the wort temp being too low? I have never used Fermcap but may try it.

hotbeer- Large diameter blowoff tube without stopper sounds like a great idea. However, I use the following Chapman 7-gallon Stainless Steel fermenters so that may not work.

I suppose if I am going to split the wort into two fermenters I can use carboys which would make a larger diameter blowoff tube easy.

Thank you all.

Steve

 

[VikeMan]

The recipe came from BYO. For the FG I am assuming the creator knows more about building and calculating a beer recipe than I do (which is none).

One would hope so. But I've seen recipes (even in BYO) where the author apparently assumes whatever attenuation his software is telling him. And when you use software that doesn't differentiate between various fermantables (from an attenuation standpoint), that usually means trouble for beers with a lot of crystal and/or roasted malts. "Why didn't my stout reach its expected FG?" is a pretty common theme on the forums because of that.

As for the yeast and oxidation staging I have seen several articles/forum posts that recommend this including advice from someone at Midwest Supplies.

Did they give any logic for adding yeast in stages?

Lastly, would using a tub with water/ice be hard to control the temp and create the possibility of the wort temp being too low?

You'd have to keep an eye on it. But I wouldn't really call it hard. A lot of people do it, at least until they acquire more automated means.

 

[BoitAHL]

VikeMan- most of the advice I see for adding yeast/oxidizing in stages for high gravity beer recommends doing this to help the yeast along and prevent stuck fermentations. Here is a link to an HBT article I found about Brewing Big Beers. Although it doesn't talk about adding yeast in stages it does mention under the Oxygenate heading a second addition of oxygen.

https://www.homebrewtalk.com/threads/tips-for-brewing-big-beers.678729/
My assumption (whether correct or not) has been since I was not hitting the FG in the recipe my yeast stopped due to lack of oxygen.

Thanks.

 

[VikeMan]

VikeMan- most of the advice I see for adding yeast/oxidizing in stages for high gravity beer recommends doing this to help the yeast along and prevent stuck fermentations. Here is a link to an HBT article I found about Brewing Big Beers. Although it doesn't talk about adding yeast in stages it does mention under the Oxygenate heading a second addition of oxygen.

https://www.homebrewtalk.com/threads/tips-for-brewing-big-beers.678729/

Yeah, the second round of aeration thing has been around for a while. I'm not convinced that it's helpful, but many are. The adding yeast in stages thing though... I don't know and can't think of any theoretical reason to do it. "help the yeast along and prevent stuck fermentations..." ok, but how does it do that?

It just occurred to me... you're using dry yeast. I wouldn't recommend aerating at all. The reason yeast need O2 is to build sterols for cell wall material. Dry yeast already has maximum sterol reserves. Adding oxygen to the wort risks (assures, IMO) oxidation, because the yeast have no use for most of the added O2.

 

[hotbeer]

Large diameter blowoff tube without stopper sounds like a great idea. However, I use the following Chapman 7-gallon Stainless Steel fermenters so that may not work.

Isn't that a stopper in the center that the airlock is in? Remove the stopper and measure the opening. Get some tubing that has an OD slightly bigger. Though I'll agree with any that think that overkill. But overkill is better than insufficient.

On the slightly more effort side of things, you can make the hole in the stopper bigger or make a bigger hole in another stopper. Just find some thin wall metal tubing and sharpen the edge. Make a T-handle on the other end of the metal tube with a piece of wood or other material. Then twist it through the rubber stopper. Don't hold it with you hand covering the other side or you'll put a hole in it too. Any kind of oil, cooking oil or mineral oil will help keep the cutter moving through the rubber.

I've made these with thin wall steel, brass or even softer copper tubing. Copper is harder to get a sharp edge on.

I'd recommend something 5/8th's ID or bigger for the blow off tube. Mine is 7/8ths for just a 5 litre fermenter. Again, overkill, but that's all they had when I went to purchase some.

 

[BoitAHL]

hotbeer-

I was thinking the thin wall steel of the cover and the size was something that would make the tubing difficult. Was also thinking it would be easy to enlarge the existing hole in the stopper. Thanks.

 

[BoitAHL]

VikeMan-

It just occurred to me... you're using dry yeast. I wouldn't recommend aerating at all. ??????

I've been brewing extract for a few years and of course am no "expert" (which is why the questions) but have never heard "do not aerate if using dry yeast". All kits and recipes I have tried, whether using dry or liquid yeast, always include aeration before yeast pitch. Am I misunderstanding and do you mean don't aerate a second time?

Thanks.

 

[VikeMan]

Am I misunderstanding and do you mean don't aerate a second time?

I mean don't aerate at all with dry yeast, for the reason I stated. There are lots of threads discussing this if you want to see what others (including some of the yeast manufacturers) have to say about it.

https://www.homebrewtalk.com/search/4111329/?q=dry+yeast+aerate&o=relevance

 

[McMullan]

As already noted, as you’re using dry yeast, oxygenation here is superfluous and more harmful, potentially. The logic backing the ‘double oxygenation‘ practice for imperial gravity worts is flawed biologically, from the yeast’s ‘perspective’. It’s actually toxic. That’s why a healthy yeast population mops it up so quickly after being pitched. To biochemically neutralize it, that is. Blasting them with pure O2 12-24 hours post pitch is just a form of biological abuse.

 

[BoitAHL]

I will check the threads out. Thanks VikeMan.

 

[BrewnWKopperKat]

it [previous batch] got nowhere near the expected FG

Are you planning to brew this with Lallemand London dry yeast?

If so, this may be of interest:

LalBrew London™ does not utilize the sugar maltotriose (a molecule composed of 3 glucose units).
Maltotriose is present in wort in an average 10-15% of all malt worts. The result will be fuller body and residual sweetness in beer. Be advised to adjust gravities and mash temperatures according to desired result.

--- LalBrew London™ – English-Style Ale Yeast | Lallemand Brewing

Given the strain of yeast being used and the fermentability of DME, you may want to double-check the 75% attenuation estimate in the recipe. The couple of times that I brewed normal strength extract-based recipes with London ESB or Windsor, I assumed 70% attenuation. The estimate was a little high, but "close enough".

 

[BoitAHL]

Kat- I am using Mangrove Jack's M42 yeast.

 

[BrewnWKopperKat]

I am using Mangrove Jack's M42 yeast.

Thanks - the recipe in the link in your OP mentioned London ESB.

I've used M42 a couple of times (APAs/IPAs) - so no insights into how it behaves in a big beer.

 

[PCABrewing]

Isn't that a stopper in the center that the airlock is in? Remove the stopper and measure the opening. Get some tubing that has an OD slightly bigger. Though I'll agree with any that think that overkill. But overkill is better than insufficient.

I used that approach too and it worked well.
I was able to find a food grade PVC at Ace hardware in the appropriate size that fit snugly into the mouth of the carboy.
The only downside was that the PVC is shipped rolled on a spool and it really wanted to maintain the curl and somewhat flattened profile. A little hot water training pretty-much cured that.

 

[BoitAHL]

Kat- Sorry about that. I did change the original recipe that was posted slightly by following some recommended tweaks.

 

[BrewnWKopperKat]

@BoitAHL : no worries. I missed (reply #6) where you mentioned using M42 this time.

 

[BoitAHL]

Thanks for all your replies. I am curious as to what Mangrove Jack's would say. Sent them a question about dry yeast aeration. Waiting to hear back.

 

[VikeMan]

Thanks for all your replies. I am curious as to what Mangrove Jack's would say. Sent them a question about dry yeast aeration. Waiting to hear back.

It wouldn't hurt to ask them, I guess, but I don't think Mangrove Jack's actually makes yeast. I think they repackage it, which would make their opinion roughly as qualified as the opinion of any homebrew store.

 

[davidabcd]

I looked over the recipe in the hyperlink. It says something like 4.9 gallons to start with, steep the grains (how long one should is discussed above) and then add the 11 pounds (or whatever) of extract. boil for an hour. That amount of extract would put a recipe way over five gallons. Is that how you proceeded, just like the recipe said? If you did it that way, it might account for why you even need a blow off tube for 5 gallons in an 8 gallon container.
I didn't check the tolerance of your yeast but you don't need anymore than 2 packs for the recipe listed.
Also, that recipe wouldn't produce a 14% ABV beer, more like around mid-11% to 12%. I use around that much extract and ABV can go even lower if I don't add sugar.
Did you mention your pitching temp above? If not, I'd like to know.
the recipe, overall, looks like a good one to make.

 

[BoitAHL]

davidabcd- Yes, I believe I proceeded exactly as the recipe is written but used all DME. Don't specifically remember the exact pitching temp but I'm pretty sure it was around 65 degrees. I always cool my wort to the temp suggested in the recipe. Yeast was re-hydrated. Used 4 packs of M42 as suggested by an HBT member.

A couple of things.
First, you are correct on the ABV. When using a calculator and I input the recipe OG and FG it comes out to 12%. Never noticed that before.
Second, I was able to find the notes I used for this brew. The OG on brew day was 1.130. The FG before kegging was 1.040. Comes out to about 11.5%.

Also, I have no recollection of the wort being over 5 gallons when poured into the fermenter. No idea if I had to remove wort or add water to get 5 gallons.

So in conclusion I'm thinking the recipe statement of 14.6% threw me into thinking my yeast was not doing it's job. The beer was pretty sweet which also led me to believe that. But since I ended up at 11.5% ABV probably the wrong assumption.

Now I just need to figure out how to prevent the super aggressive fermentation from blowing out a gallon of my beer.

Thank you.

 

[davidabcd]

Now I just need to figure out how to prevent the super aggressive fermentation from blowing out a gallon of my beer.

If you did use 4.9 gallons for starters, the 11 pounds of DME would push the volume well past 5 gallons. Is your ss fermenter graduated? If not, maybe it just looked normal in the fermenter. But, lacking further info, it's something to take notice of next time. My theory is still that the space was reduced because of initial water volume. I use two packs for some high ABV beers and it doesn't come anywhere close to needing a blow-off tube. I can't say that the four packs wasn't the culprit either (which is a lot of yeast).
Thanks for the rest of the info and your brewing process looks pretty solid.
As I said earlier, nice recipe.
Edit: Just so you don't miss out on receiving replies, either type "@" with the person's screen name or just highlight some of the poster's text and then you'll see a reply option. That'll let the person know you posted something.

 

[BoitAHL]

Edit: Just so you don't miss out on receiving replies, either type "@" with the person's screen name or just highlight some of the poster's text and then you'll see a reply option

Thanks for the advice on this. Was wondering how it was done.

Is your ss fermenter graduated?

Yes it is graduated so I'm certain the wort volume was no more than 5.25 gallons.

 

[davidabcd]

Yes it is graduated so I'm certain the wort volume was no more than 5.25 gallons.

Good to rule that out.
Being that's the case, it could narrow the reason for the explosive nature of your fermentation to using four packs of MJ 42. More isn't necessarily better and no matter how much yeast is used, it will only ferment to the level for which it is designed. Using enough not to stress the yeast is good though.
I have never tried four packs in a five gallon batch for the ABVs I attain (12%-14%), so I could only imagine what may happen. If one works out the yeast necessary for such a batch, it comes to less than two packs. I use two anyway, though that might be as necessary as tossing salt over my shoulder.
This might just be me, but the thought of losing any beer to blow-off, if it can be avoided, is not a pleasant one. It seems like an unnecessary waste.
Using the 7.9 gallon (basically 8 gal) with 5 gallons of beer to ferment has never resulted in a krausen so large that it blows through the airlock. 5/8 filled leaves a huge amount of wiggle room.
I'm a bit of a "late to the party" type so what I'm about to say isn't new news. I noticed recently that some of the Kveik yeasts can ferment up to 15%. It would be great in a stout I think. Something to look into.

 

[Snowmanii]

I read somewhere to use yeast nutrient at the end of boil and one or two more times in the next two days with a high ABV beer. Look at wine or Mead makers, they always use it (or at least should). And I just brewed an 11% calculated Stout with 2 sessions of nutrient and kveik from my kveikstock and hit 11.16% (og was slightly low and fg made up for it and more). 1, this was my first Stout with kveik yeast. 2, the first time I have hit or surpassed my calculated numbers. 3, I also always oxygenate my wort coming out of my chiller.

 

[BoitAHL]

All,

So I brewed this beer on Sunday using all the steps as before with one difference. I did split the wort into two fermenters with enlarged blow off tubes. This morning I do have fairly aggressive fermentation but nothing close to the overflow from my two previous attempts (one fermenter) which wasted 1-1.5 gallons.

FYI- OG was a whopping 1.160

Thanks for all your advice. Very much appreciated.

 

[hotbeer]

Something you might want to try next time. Figure out how to run the tubes straight up vertically from the fermenter for a 6 to 12 inches or more. That might let the liquid brought as bubbles run back down into the fermenter instead of down to your bubbler vessels.

The 7/8" ID tube I use is so thick, that it will support itself for that little distance.

I did wake up today and found the current batch in the fermenter maxed out it's krausen last knight and actually got into the blow off tube. However it wasn't able to make if far enough up to get past or near the bend which for my 5 liter fermenter is about 6 inches higher than the top of the fermenter and about 9 inches higher than the surface level of the beer inside.

 

[BoitAHL]

Figure out how to run the tubes straight up vertically from the fermenter for a 6 to 12 inches or more.

That is an excellent idea.

 

[BoitAHL]

Update.

Primary fermentation went very well. Added the Cherry Puree at the designated time. About 2 weeks of decent activity then let it sit another week. The splitting of the wort into two fermenters worked perfectly. Did not lose any volume this time. Before racking onto the Cholaca and Vodka-soaked vanilla beans took a gravity reading. Came out at 1.060 from 1.160 OG so I'm looking at a bit over 13%. I am very very happy. Taste was damn good right out of primary with just the Cherry Puree added and was not super sweet like last time. Racking onto that chocolate was making my mouth water. I keep telling myself be patient, but I want to crack open the secondary and start drinking right from the carboy!!!! Unfortunately, the instructions now say, "age to desired taste". I really hate opening up the secondary, or primary for that matter, to take samples so I have not decided how long in secondary yet. I think I will repost the recipe with the couple of tweaks I did when the beer is ready (and of course tastes fantastic)! Also, I think I figured out why the OG was a whopping1.160. Was supposed to put in 1lb of Munich DME but could only get a 3lb bag and of course I put in all 3lbs.