General Attenuation Question: Lutra Kviek

[Sun_Lizard]

This may be a newbie question, but I'll go ahead and ask it:

I've been using kvieks a lot in recent months due to the premium on fridge space for other projects. I've used Lutra Kviek about 4 times other than the beers below and I seemed to have hit my other FG numbers accurately.

The last three batches I've made using using Lutra Kviek (dry) and a similar grain bill (Crisp Maris Otter as the principal) have all fermented out typically .005 above what was calculated by my brewing software. (I know that's not a huge amount but its consistently above what I'm trying to achieve which means I've got something wrong with my method. What factor most affects FG? And is there anything I might correct or add to my process in achieving those last few points?

Here's the relevant details.
All batches were temp controlled at around 27C, all done under pressure of 12 psi. All were 5.5 gallon batches.
All readings were done by hydrometer.
All of my batches were BIAB.
All fermentations behaved normally, and hit FG numbers with 48-36 hours but were left at least 1 week longer to see if anything else happened.
Water profiles were slightly different, as expected. I do have to change alkalinity of my water to get it into 5.2-5.4 range (usually with 4-8ml of lactic acid before mashing.)

Batch 1 (IPA)
80% Crisp Maris Otter:
Mashed 60 Min @65, no Mashout
Boiled 30 min
OG: 1.056
FG: 1.015
FG: (calculated/expected) 1.010

Batch 2 (Pseudo Helles)
88% Crisp Maris Otter
Mashed 60 Min @ 65, with Mashout at 75 for 10.

Boiled 30 min
OG: 1.065 (way over my target)
FG: 1.015
FG: (calculated/expected)1.011

Batch 3 (Pale Ale)
Mashed 90 Min @ 62, with Mashout at 75 for 10
Boiled 30 min
95% Crisp Maris Otter.
OG: 1.052
FG: 1.015
FG: (calculated/expected) 1.009

My initial guess is that its Crisp Maris Otter not attenuating like its profile suggests. Aside from changing the base malt, is there anything I can do to 'dry' out the beers?

Granted, all of the beers have been 'good' but I really want to understand what I'm doing to be not getting all the way down and if there's anything I can do to go from good to great.... Thanks in advance.

 

[Toxxyc]

You can invest in a bottle of glucoamalyse added to the fermenter with pitch. It's a fermentation-phase enzyme that'll break down longer sugars and make the wort more fermentable, so the Lutra should eat more of it. It's typically used by guys making highly fermentable worts for yeast.

Personally, if you want to do dry, go for a lager yeast and handle it the way it should be. You can ferment under pressure so cold temps aren't even required. It's clean and dry, and "crisps up" a beer like no other.

 

[DBhomebrew]

which means I've got something wrong with my method.

Or perhaps the software prediction is off?

 

[Sun_Lizard]

invest in a bottle of glucoamalyse

Thanks. I think I have some powder Gluco-Amalayze I got for another fermenting project but never used... I'll read up on on it and let you know if it works out. Just quickly: Do you need to add it at pitch time, or could I add it late stage in the fermentation?

 

[Sun_Lizard]

Or perhaps the software prediction is off?

Maybe. Using BrewFather (although I do have BeerSmith and haven't entered the recipe into that to see if it gets different results.) I also thought it might be actual batch of malt, but the last batch was done with a fresh sack....

Cheers!

 

[Toxxyc]

Thanks. I think I have some powder Gluco-Amalayze I got for another fermenting project but never used... I'll read up on on it and let you know if it works out. Just quickly: Do you need to add it at pitch time, or could I add it late stage in the fermentation?

I believe when pitching. You want it to work as long as possible to break down as much long-chained sugars as possible.

 

[Miraculix]

Enzymes will bring it down to 1.0 or below, wouldn't go that route tbh. If you want to mash for fermentability, do a hochkurz mash. 30 minutes @62c followed by 30 minutes @72 followed by 15 minutes mashout @77c.

But to be honest, I do not understand your obsession with hitting a number that a software gave you, especially if the beer tastes fine to you. Just accept that software is not a perfect representation of the real world and enjoy your beer.

 

[Toxxyc]

^ I agree. The xBMT tests have shown that people can't really taste between 5 gravity points at all anyway.

 

[DBhomebrew]

Maybe. Using BrewFather (although I do have BeerSmith and haven't entered the recipe into that to see if it gets different results.) I also thought it might be actual batch of malt, but the last batch was done with a fresh sack....

Cheers!

My understanding is that FG is one of the more difficult things for a software/spreadsheet to predict. Most don't even make the attempt to account for grist makeup such as sucrose vs crystal malt.

 

[madscientist451]

Aside from changing the base malt, is there anything I can do to 'dry' out the beers?

Try an overnight BIAB mash. Right before you go to bed, get your mash going. Wrap up the pot in an old coat or sleeping bag and call it a night. I use a solid top electric range for BIAB so the stove holds heat somewhat, your setup may be different, but it will likely work about the same. In the morning pull the bag and get the boil going. I've used the technique when brewing "brut IPA" and other beers where I want a low final gravity and it works for me.

 

[DonT]

Attenuation for lutra is 75-82%. It looks like you're right in that range... Try bumping fermentation temp up to 30C and see what that does. Or... bump the temp after a few days at 27C.
Do you oxygenate? Or use yeast nutrient?
Try switching to liquid Lutra and make a starter....

 

[balrog]

Slightly different dry Lutra batch affecting apparent attenuation? You don't show examples of other batches the worked "fine", but the 3 you specify have apparent attenuation of 71-77%, not obviously affected by mash temp (65 vs 62), or OG(1.052 to 1.065). Notably, all 3 ended at exactly 1.015, which I find curious. I agree with @Miraculix that enzymes are kinda nuclear option and may dry out, thin out, the final beer significantly, and you should try mashing lower/longer first.

 

[Toxxyc]

I personally think working with att % is the wrong way of going about this if you're brewing beers in succession. If you really want to test attenuation, you have to ensure you have the exact same wort between the batches of your test, and most homebrewers simply can't control the mash temp well enough to ensure the same wort with the same fermentable sugars end up in each test. So if you really want to test it, make a batch of wort, freeze it in bits and use each for a test. Even a 1°C change in mash temp will affect the fermentability of the wort, the time it takes to get to boil affects the fermentability of the wort, the time it spends in the kettle affects it, etc. etc. and all that will affect the apparent attenuation.

So tl;dr stop worrying about it and if you want a drier beer consistently, get a better attenuating yeast.

 

[Albany brew guy]

generic response but appropriate for any time measured results are curious - check accuracy of equipment.

Did you calibrate your hydrometer? These can be off a point or two easily. Additionally, were your test parameters correct? (Temp)

To that end, I have used Lutra a handful of times and have a friend that has used it extensively. Most batches I have observed made with Lutra don't have attenuation at the higher end for the strain so far...