Under cooked a Stout

[Shaft]

Did a 20 litre batch of an Irish Guinness style stout. Hit my marks and started at 1.044 OG. I was using a rather old sachet of Kviek Voss dried yeast I've not tried before. It's supposed to love high temps, and finishes in a about 3 days. Kept it in my hotbox at about 35c and all things were going fine, but flatlined at 1.016, and hasn't moved for 2 days, when I was aiming to reach 1.010. I've ended up with a 3.6% instead of a 4.5%.

Not great, but not sure what I should do with it now. Try a secondary ferment? It tastes ok, but if anything, I was planning to split it into 2 batches and add coffee to one, which would only dilute it further. I'm guessing the old yeast is the problem.

 

[Pennine]

Not much you can do at this point but to drink it.

You can also add coffee beans directly to it rather than brewed coffee if you don't want to dilute it anymore.

 

[Jan.]

1.044 to 1.016 is an attenuation of 62.8%, I have checked the stats for this yeast and the attenuation range is meant to be 76-82% so it definitely didn't hit its full potential. Maybe because, as you mention, as it wasn't as fresh as it could have been.

I would not try a second ferment as when you pitch more yeast you are pitching into very sub-optimal conditions (no oxygen, low sugar, low PH etc.) and the results won't be great.

Shaft's idea is the best, add the beans rather than the coffee, the end result will have about the same final alcohol. Or if you really want a bit more of a kick you could add some coffee liqueur along with the beans.

 

[Sadfield]

1.044 to 1.016 is an attenuation of 62.8%, I have checked the stats for this yeast and the attenuation range is meant to be 76-82% so it definitely didn't hit its full potential. Maybe because, as you mention, as it wasn't as fresh as it could have been.

Kveik yeasts really don't like low gravity, unfermentables worts. It's not what they evolved to brew, they require more nutrients than standard brewing yeast at lower gravity. Freshness shouldn't be the issue as they usually perform well when underpitched.
https://www.garshol.priv.no/blog/393.html

 

[Shaft]

1.044 to 1.016 is an attenuation of 62.8%, I have checked the stats for this yeast and the attenuation range is meant to be 76-82% so it definitely didn't hit its full potential. Maybe because, as you mention, as it wasn't as fresh as it could have been.

I would not try a second ferment as when you pitch more yeast you are pitching into very sub-optimal conditions (no oxygen, low sugar, low PH etc.) and the results won't be great.

Shaft's idea is the best, add the beans rather than the coffee, the end result will have about the same final alcohol. Or if you really want a bit more of a kick you could add some coffee liqueur along with the beans.

Funnily enough I was considering the coffee liqueur option, so good to hear a second opinion in that direction. I've a couple of free kegs, so could split the batch and try both options. Will report back which works better. Thanks for taking the time to check the stats on the yeast!

 

[Jan.]

No probs. Good luck with them and let us know how they turn out.

 

[Shaft]

No probs. Good luck with them and let us know how they turn out.

Great link too, may get some more Kviek yeast. Although it didn't get the attenuation, it was done in about 36hrs as this article suggests is possible. Nuts. Perhaps it was a nutrient deficiency. Easy to harvest too and keep for 20yrs in the freezer with the right strain.

 

[Jan.]

Great link too, may get some more Kviek yeast. Although it didn't get the attenuation, it was done in about 36hrs as this article suggests is possible. Nuts. Perhaps it was a nutrient deficiency. Easy to harvest too and keep for 20yrs in the freezer with the right strain.

I haven't tried a Kviek yeast before, not sure why, normally I jump on anything new or different. I'll have to bite the bullet at some stage. 36 hours is insane, though! The F1 of yeast!

 

[BobShandy]

1.044 to 1.016 is an attenuation of 62.8%, I have checked the stats for this yeast and the attenuation range is meant to be 76-82% so it definitely didn't hit its full potential. Maybe because, as you mention, as it wasn't as fresh as it could have been.

I would not try a second ferment as when you pitch more yeast you are pitching into very sub-optimal conditions (no oxygen, low sugar, low PH etc.) and the results won't be great.

Shaft's idea is the best, add the beans rather than the coffee, the end result will have about the same final alcohol. Or if you really want a bit more of a kick you could add some coffee liqueur along with the beans.

Is there a sanitary way to add oxygen to this beer? If you sanitized a whisk, or the detachable whisks from an electric whisker, is there a big risk for contamination?

I wonder if anyone tried using an "oxygeniser" like a device for pumping air into a fish tank?

How about adding some dry/liquid malt extract for sugars and then pitching the fresh yeast?

 

[LeeH]

Adding 02 now would be beer suicide.

 

[BobShandy]

Adding 02 now would be beer suicide.

Because of contamination or some other reason?

Should I be worried about opening a fermenter to take a sample to check it with a hydrometer?

 

[Jan.]

Is there a sanitary way to add oxygen to this beer? If you sanitized a whisk, or the detachable whisks from an electric whisker, is there a big risk for contamination?

I wonder if anyone tried using an "oxygeniser" like a device for pumping air into a fish tank?

How about adding some dry/liquid malt extract for sugars and then pitching the fresh yeast?

You could theoretically add oxygen if you had an oxygen tank with perfectly pure oxygen and a sanitary way to administer it. Sanitizing a whisk wouldn't work as it is not just the utensil that has bacteria/yeast it is also the air itself that you would be whisking into the beer. However, it is irrelevant as oxygen itself would seriously degrade the beer and cause oxidation (papery, cardboardy flavours) and perhaps some strong esters if further fermentation happens, so I would not advise even trying.

Adding some more sugars, then more yeast is not a good idea either. The yeast need oxygen to multiply (which would degrade the already present beer) and pitching yeast into a substance with very little oxygen, a lower than perfect PH, and in the presence of alcohol will mean that the fermentation will be awful and possibly create unwanted phenols, esters and higher alcohols (it may not, but it is a big risk). I would try to enjoy what you have made and then make a better one next time (you never know, this one might be great even with a lower alcohol content).

 

[Jan.]

Because of contamination or some other reason?

Should I be worried about opening a fermenter to take a sample to check it with a hydrometer?

Any air contact, or touching the beer will have a slight risk of contamination, it is very difficult to avoid bacteria, yeast and oxidation completely. If you are able to take a sample from the fermenter's tap, it is ideal. If it hasn't got one though, don't worry too much. If you are taking a sample when it is close to or at its final gravity then the beer itself is more sturdy and less susceptible to contamination.

As long as you are not taking a sample every hour and you sterilize the equipment that touches the beer and close the fermenter when you are done, you have nothing much to worry about.

 

[BobShandy]

Any air contact, or touching the beer will have a slight risk of contamination, it is very difficult to avoid bacteria, yeast and oxidation completely. If you are able to take a sample from the fermenter's tap, it is ideal. If it hasn't got one though, don't worry too much. If you are taking a sample when it is close to or at its final gravity then the beer itself is more sturdy and less susceptible to contamination.

As long as you are not taking a sample every hour and you sterilize the equipment that touches the beer and close the fermenter when you are done, you have nothing much to worry about.

Thanks. I was concerned because my beer stopped bubbling after the first 24 hours of bubbling and I thought I would have to open it up to do some wort surgery. That is why I asked.

Luckily it turned out the airlock was slightly twisted and letting CO2 escape. I set it right and it is back to bubbling noisily once every 3 seconds.

 

[Jan.]

I hate airlocks, they always provoke people to make mistakes. They stop bubbling and people mess with their beer to get it bubbling again. Or they don't start bubbling so they tempt you into doing something you shouldn't. Destroy the airlock, it is evil, blow it up!

Seriously though, you did the right thing and it sounds like it's going perfectly. Good luck and let us know how it goes

 

[Shaft]

Update

I split the beer into a couple of 10L batches:

Batch 1: Just added 2.5ml of Lactic Acid 80%

Batch 2: Added 150ml of fresh espresso and 550ml of Kahlua

Put both kegs into 30/70 Mix gas on the 20th at 35psi.

Just sampled each. Both had a nice head and a fairly creamy taste but the head did dissipate fairly quickly after a few sips. May need a few more days. I'm new to using a nitro mix and stout tap, so not sure.

In terms of flavour the Batch 1 isn't far off a Guinness all be it noticeably a little light. Pretty good and the lactic seems to have done a pretty good job of getting that slightly sour taste

Batch 2 is really good, nice coffee flavour although not over the top. Good level of strength too. Very happy given the fudging.

I'm just hoping a few more days on gas (8 so far) will cream it up a bit more. Any experienced thoughts on this would be appreciated. I don't want to risk turning the gas up further and over carbonating it.

 

[Bzee]

Did the sugars in the Kahlua ferment out or has it added a sweetness.

 

[YeastFace]

What temp are the kegs at?

The fats/oils in Kahlua may well impact on head retention.

 

[Shaft]

Did the sugars in the Kahlua ferment out or has it added a sweetness.

Added some sweetness, but not much as offset by the bitterness of the coffee. I tried a few variations of ratios before settling on the amounts.

 

[Shaft]

What temp are the kegs at?

The fats/oils in Kahlua may well impact on head retention.

Haven't cold crashed them. Prob about 10C.