Breakfast Stout with US-05 Stalled

[Brewshna]

Hi Guys,

our next try at a bigger stout has once again failed.
We watched the whole process carefully, especially the mashing temp.
We had no problems or mistakes that i can think of.
Pitched 4 packs of 05 at about 22°C. Aeration by vigorous overhead shaking of the fermenter before pitching the rehydrated yeast.
OG Was 20.4P (1.084) and FG should be 4.6P (1.019), after 3 weeks and two following same measurements of 7.2P (1.029) its as far as it will go.
I'm wondering if Aeration is lacking for that Gravity but im just not sure where the problem lies.
Any ideas?

The Recipe: Brewfather

Thanks
Matt

 

[VikeMan]

I don't know where the expectation of an FG of 1.019 came from, but IMO it's probably not realistic. I put your grain bill, mash paramenters, and yeast strain into BrewCipher, and for an OG of 1.084, it predicts an FG of 1.027, which is very close to the 1.029 you're at. The main drivers are your relatively high mash temperaure and relatively unfermentable grain bill.

 

[Brewshna]

That does sound right...
I followed this clone recipe, and used the OG/FG given by Brewfather

 

[Miraculix]

You mashed at 68c, this results in lots of unfermentable sugars. Next time, mash at 62 and possibly also half an hour longer and you will have a lower fg.

Your current stout is probably still nice, just a bit more body and flavour.

 

[Brewshna]

The recipe called for a 68C mash, I think most stouts do. Our mill is rubbish, that probably caused our OG to be a bit low.

 

[Miraculix]

The recipe called for a 68C mash, I think most stouts do. Our mill is rubbish, that probably caused our OG to be a bit low.

Depends. If you want a high fg, you got to mash high, as you did. But don't complain about a high fg afterwards. The fg listed in the recipe is unrealistic with the given mashing schedule. Bad recipe imo.

If you want a strong stout with a lower fg, use 90% pale, 8% roast and rest crystal (you can skip the crystal if you like). Mash @ 62 c for 90 minutes and enjoy the higher fermentability!

 

[Brewshna]

Ok, still learning the trade. Thanks for the answers.
Just one more, would aerating the wort with pure oxygen have helped with the FG at all? (Probably not if the sugar isn't fermentable)

 

[Miraculix]

Ok, still learning the trade. Thanks for the answers.
Just one more, would aerating the wort with pure oxygen have helped with the FG at all? (Probably not if the sugar isn't fermentable)

Maybe a little bit, but the effect would be probably minuscule.

 

[Brewshna]

Weird about the recipe, its a bought BYO Magazine clone Recipe

 

[Miraculix]

Weird about the recipe, its a bought BYO Magazine clone Recipe

Looks much too complicated for me. Keeping things simple results in better beer. There's no need for three different roasted malts for example. Looks a bit like someone tried to get fancy.

 

[VikeMan]

Weird about the recipe, its a bought BYO Magazine clone Recipe

A problem is that most recipe build software doesn't care about the makeup of the grain bill when predicting attenuation, and many of them don't care about mash parameters, but people tend to trust the answers anyway. I've seen plenty of unrealistic FGs in magazine print. "My stout didn't reach its expected FG" is a common enough forum thread that it practically deserves a sticky.

 

[jerrylotto]

One thing that helps with big beers is to ease the yeast into action. Make a starter, even with four packs, to make sure it's all hydrated and active by diluting some of your wort with water before pitching.

 

[Brewshna]

The software is a problem, especially for beginners. I know that most specialty malts lack the enzymes for convertion, but thought the enzymes in base malt make up for it. Also that higher mashing temp produces thicker, less fermentable Wort, which brewfather takes into account. Difficult

 

[VikeMan]

The software is a problem, especially for beginners.

Well, it's not as much of a problem if using software that addresses the problem! BrewCipher considers grist makeup when prediction attenuation. At least one other tool has added it too, but I don't remember which one. (It's not BeerSmith.)

I know that most specialty malts lack the enzymes for convertion, but thought the enzymes in base malt make up for it.

It isn't (mostly) an enzyme issue. It's the fact that specialty malts, to various degrees, have already had some of their starches converted into unfermentable compounds (like caramelized sugars, etc.).

Here's a slide from an attenuation presentation I did a couple years ago. The data is derived from trials that Greg Doss (Wyeast) did a while back. There are obviously also (not shown here) factors other than grain bill (i.e. mash parameters, yeast strain), but the chart is useful to understand the relative fermentability of various grain types.

 

[Brewshna]

Great replay, thanks a lot.

 

[Dgallo]

As @VikeMan said, this is an extremely common occurrence on HBT. Recipe kits/posted recipes tend to go on potentials for grains/attenuation and don’t take mash temperature into account. I brew stouts with similar % as this recipe and og, if I mash 68 (154.5*f) I would finish 1.026-1.031 range. I def would not repitch or aerate at this point. Your most likely done and all that will do is add Dissolved oxygen to your beer

 

[Miraculix]

As @VikeMan said, this is an extremely common occurrence on HBT. Recipe kits/posted recipes tend to go on potentials for grains/attenuation and don’t take mash temperature into account. I brew stouts with similar % as this recipe and og, if I mash 68 (154.5*f) I would finish 1.026-1.031 range. I def would repitch or aerate at this point. Your most likely done and all that will do is add Dissolved oxygen to your beer

You forgot a "not"!

 

[Dgallo]

You forgot a "not"!

Fixed. Thanks brother

 

[couchsending]

You don’t need too add O2 with dry yeast. And making a starter sign dry yeast can actually decrease the viable cell count.

Next time make a little beer first and use the slurry.

Your milk might be no bueno but your efficiency also goes way down with larger grain bills. Happens to everyone. Also in my opinion most calculators overestimate the sugar contribution of oats.

That being said a FG that high is not necessarily a bad thing. The highest regarded Robust Porter in the worldis 7.5% and finishes at 1.030. Most higher ABV roasted beers these days finish much higher than that. Some even finish as high as 1.080...

 

[VikeMan]

^ Just to hopefully avoid confusing @Brewshna, the issue he was concerned about was a higher than expected FG, i.e. not an efficiency problem (due to grain bill size) or an issue with expecting a higher yield from the oats.

That being said a FG that high is not necessarily a bad thing. The highest regarded Robust Porter in the worldis 7.5% and finishes at 1.030. Most higher ABV roasted beers these days finish much higher than that. Some even finish as high as 1.080...

I do variations on a "Pastry" Stout where the base beer's FG is right at 1.050+-.001. They tend to be popular with the kids at brewfests.

 

[superiorsat]

I personally don't take much delight in drinking overly sweet beers. I would taste it and if it is too sweet I would feed it a little honey to get it going and through in fresh pack of US-05 to get some fresh soldiers on the job. I think you could probably shave a few points off of where you are now ( done it enough times to know it works and basically always plan on feeding big beers to get them across the finish line, not that I would consider this beer particularly big). You aren't even at the abv yet for the recipe so you might just as well feed it and get it going again to see what happens. Luckily this has coffee in it and if your end product is still to sweet add more coffee to offset the sweetness. Sometimes just 2 to 3 gravity points makes all the difference.

 

[Brewshna]

Tasted the measurements and yes a bit sweet, but not too bad. 2 months in a secondary, just getting there before bottling should help mellow everything a bit

 

[Brewshna]

So I love big stouts and would love to brew a 12% chocolate stout in a vault city style. massive chocolate without too much sweetness. how do I brew a big beer like that on my 30l system? usually do the 4gallon batches and guess I'd have to reduce output for much bigger beers with a lot of body.

 

[Brewshna]

or reiterated mashing, which I still have questions about

 

[davidabcd]

As mentioned, that's about where it should end up. The only difference in my experience is my OG is above 1.100 for those types. I was put off the first time I did a Dragon's Milk clone (1.030 FG) but my OG was 1.110.

 

[superiorsat]

On big beers like 12%-er's with your 30L equipment you could do 2 mashes and just take first running's maybe save second running's for a parti-gyle beer if you did a back to back brew. You could also up the gravity with extract in the boil. You could feed the yeast during fermentation to get to 12% that is how I use to do it back in the cooler mash tun days. IME stouts that big have plenty of body ( for me but I don't want to cut a beer with a knife either ) even without mashing at high temp. I mash those at 150F which helps on getting the FG down to not cloying sweet area and again I always plan on ( factor in to my SG ) feeding the yeast to make sure they get the job done.

 

[Brewshna]

what do you mean by, "feeding the yeast"?

 

[VikeMan]

what do you mean by, "feeding the yeast"?

He means starting with a wort that would normally finish at something less than 12% and then give it fermentable sugars incrementally after most of the initial fermentation is finished.

That said, I have made 12%+ ABV stouts and have never incrementally fed any of them. Pitch an adequate amount of healthy yeast, oxygenate the wort thoroughly (if using liquid yeast), use a yeast nutrient (maybe not absolutely needed, but I do it), and use a yeast strain that has a typical ABV tolerance higher than your target, and shouldn't need to feed incrementally.

 

[superiorsat]

I don't think it is required either but I don't necessarily feed to try to get to 12+.just saying with his limited capacity it is one way to go. Feeding close to the end is just a habit I've got at the moment on big beers because I think it helps finish quicker. 3 weeks max for any beers I make and anything under 10% usually gets kegged on day 13. Lots of ways to go about this process, part of the reason it is so fun. Lots of good info for Brewshna on this thread.

 

[VikeMan]

Feeding close to the end is just a habit I've got at the moment on big beers because I think it helps finish quicker.

I have some doubts that adding simple sugars actually encourages the yeast to finish the remaining (complex) sugars, which are pretty much all maltodextrin at/toward the end. It's a significantly different chain of events (metabolically) for the yeast. But if you think it helps, I won't say that you shouldn't do it.

Just be aware that adding (say) a pound of table sugar to a 5 gallon batch will result in an FG a little more than 2 points lower, just from the fermentation of the added sugar (i.e. not the residual sugars), because of ethanol being less dense than water.

 

[Davedrinksbeer]

Ok, still learning the trade. Thanks for the answers.
Just one more, would aerating the wort with pure oxygen have helped with the FG at all? (Probably not if the sugar isn't fermentable)

i bought a wine degasser wand for $20 that’s hooks into a power drill. Works great

 

[VikeMan]

i bought a wine degasser wand for $20 that’s hooks into a power drill. Works great

Perhaps you already know this, but there's a limitation with oxygenating with a wine degasser. It's the same as with shaking, about 8 ppm O2 (or maybe a little higher). The reason is that once you reach equilibrium, any more O2 you gain by further agitation is offset by O2 lost due to the same agitation.

 

[Davedrinksbeer]

Perhaps you already know this, but there's a limitation with oxygenating with a wine degasser. It's the same as with shaking, about 8 ppm O2 (or maybe a little higher). The reason is that once you reach equilibrium, any more O2 you gain by further agitation is offset by O2 lost due to the same agitation.

agree, a wine degasser wand though works better than shaking the $hit out of a bucket or carboy.

 

[superiorsat]

Years ago my neighbor decided he wanted to get set up for 4 kegs in his fridge so I helped him and he contributes to ingredients and keg cleaning days and such. I have had years of split batch side by side comparisons to check this line of thinking. The strong beers being the best example for this case I would do side by side everything identical with 1 exception one way or another. Like adding pure oxygen to one and not the other when using dry yeast even though you don't need to and some suggest you might even be doing harm by doing this . The only thing that I ever got out of that was The O2 added one was a quicker take off but in the end same FG and flavor. Brewing big beers when I first started seemed like I was waiting for ever to get those last few points so you look to the forums and get stuff like try to gently rouse the yeast and maybe raise the temp a little which are both good pieces of advice but too slow for my liking. I was under the impression early on in this hobby that all simple sugar additions should try to be held off until fermentation was basically done so the yeast didn't go after the easy sugars and give up on the more complex sugars. I've done enough kettle additions, brown sugar, honey, treacle, etc.. and I didn't see any stuck/stalled fermentations so I kind of threw that out the window. I see late feeding as a way not just to rouse some tired not energized yeast to try to eat the last more complex sugars but to get the health guys eating and hungry and when that little sugar rush runs out they take what ever they can get because they are energized and have some gas left in the tank and aren't ready to go back dormant just yet. Kind of like my dog will lay in the garage with a bowl full of food and not touch it but once I give him something off my plate he will then tear into his food as I got his hunger going. Obviously not apples to apples but it is a nature thing. Anyway I would hit my stout with a pound of honey ( did this on 3 occasions )and not his. The first time I didn't check for final gravity until we kegged it. Mine was good at 1.022 his was too sweet at 1.026. Warmed his back up added a pack of yeast and it took a week/week and a 1/2 to where his got to 1.024 and bottomed out but like I said earlier a couple points can make a difference taste wise. Did this same thing a couple more times but checked everything before kegging and both times his beers took about a week and a half longer. The other advantage of all this split batching is you can go multiple directions different yeast, fruits , dry hops etc.. I know it isn't an exact scientific experiment but it has convinced me enough that I'm now in the habit of doing it.

Just be aware that adding (say) a pound of table sugar to a 5 gallon batch will result in an FG a little more than 2 points lower, just from the fermentation of the added sugar (i.e. not the residual sugars), because of ethanol being less dense than water.

I get that but even though I may or may not be getting anymore of the complex sugars ( usually get about a 5-6 point drop from where fermentation starts inching along with the honey addition ) being diluted a little more with ethanol is diluted more none the less reducing sweetness a smidge . Less sugar per drink lets say. Keep in mind I think the points I am talking about would come off with time I just don't want to wait and I plan for this so I'm not overshooting the expected ABV. These are just my experiences and just throw it out there for others to do what they will.

 

[VikeMan]

I get that but even though I may or may not be getting anymore of the complex sugars ( usually get about a 5-6 point drop from where fermentation starts inching along with the honey addition ) being diluted a little more with ethanol is diluted more none the less reducing sweetness a smidge . Less sugar per drink lets say.

It's not really much less sugar per drink, assuming we're just talking about the impact of the fermentation of the added sugar. The added ethanol from that pound of sugar will result in roughly 1/2 pound of alcohol, or less than 10 fluid ounces. That would be less than a 2% change in the concentration of sugars/dextrins. If you can taste a difference in sweetness for less than a 2% concentration reduction in complex sugars/dextrins, I'm impressed!

 

[superiorsat]

I'm pretty sensitive to sugar like that. Lets say a stout at 1.026 is too sweet for me, but maybe something just a point or two different like 1.025 or 1.024 I can get on board with. All depends on the beer. I've done plenty of dumb stuff fighting this compulsion. Beano to try to convert more complex sugars so they can be fermented. Adding coffee or hops or oak tea to offset sweetness. etc.. I had a stretch years back when my neighbor got involved where I went from 10 gallon coolers to 20 gallon stainless mash tun and HLT ( always had 20 gallon BK ) and stupidly didn't calibrate my new thermometers. They were off to say the least so I was more than splitting the difference thinking my analog was 3/4 the way down in the MT and if the analog was at 153 lets say the temp probe from my herms recir would have to be at 159ish from my controller to have the analog that was out of whack where I thought it should be. This generated a couple months of beers that had a FG too high for me (probably mashing 158+) and on with the fixes and methods to combat this. Then the light bulb of stupidity went on and I realized what was going on. That was the stage where I learned my palate to sugar is very sensitive.

 

[dmtaylor]

Sorry I’m late.

Did you perform a refractometer conversion calculation to account for presence of alcohol in the FG sample? Looks like probably not? You NEED to.

https://www.brewersfriend.com/refractometer-calculator/
https://www.homebrewersassociation.org/forum/index.php?topic=28544.15

 

[Brewshna]

used a hydrometer to test.

 

[Brewshna]

Here's the last reading

 

[dmtaylor]

Oh, well that's good. Nevermind.