FG too high!

[DominicRL]

Hello folks!

I recently brewed David heath’s milkshake IPA, and the short of it is on the day I ended up with an OG of 1.072 instead of the expected 1.060 (but with the target volume - not quite sure how I managed this, perhaps a very slow sparge!) I added 500ml of sterile water to the 14.5l of wort just before moving to primary, which I later realized was a litre and not gallon correction so my OG will still have been 1.070.

After the recommended time in primary, and additions of fruit/dry hops etc the gravity seems to have settled on 1.020. So it’s the correct ABV but 10 points higher gravity than the target of 1.010. I’m going to leave in secondary for at least another week to be safe (it’s tasting good!) but my question is, would you guys expect this given the OG was so high, or should I be trying to rouse the yeast somehow for those final 10 points?

All thoughts gratefully received!

Best,
Dominic

 

[obscure]

If I am bottling then honestly I probably would as I would be a tad nervous about the yeast slowly eating away at the sugars and ending up with bottle bombs.

If I was kegging and it tastes good I would probably just go ahead and keg, especially a beer like thos where I assume you plan to drink it in a fairly short time frame?

 

[Sandimas]

What yeast did you use?

Yeasts all have a typical performance (attenuation), so if your orginal spec was 1060->1010 but your OG was too high 1070, 10 points higher, chances are it's going to finish 10 points higher i.e. 1020. Knowing what yeast you used would allow us to calculate this and confirm if it's done.

 

[DominicRL]

What yeast did you use?

Yeasts all have a typical performance (attenuation), so if your orginal spec was 1060->1010 but your OG was too high 1070, 10 points higher, chances are it's going to finish 10 points higher i.e. 1020. Knowing what yeast you used would allow us to calculate this and confirm if it's done.

Ah now that is something I did not know! I used Mangrove Jack’s M66 yeast - to try and pull out as much of the fruit flavour as possible. Very grateful for your help on this!

 

[Chippy_Tea]

As you know I don't brew so wondered how a slightly high FG effects beer in wine making a slightly high FG would mean it was a little sweet so still drinkable.

 

[Sandimas]

MJ66 attentuation Medium (74-82 %). Yeast attentuation formula is (OG-FG) / OG x 100

So for OG 1070 finishing at 1020 = 70 - 20 / 70 x 100 = 71%....outside yeast tolerance, so your brew probably has a bit more to drop.

And OG 1070 finishing at 1010 = 70 - 10 / 70 x 100 = 86% .... outside yeast tolerance, so it's not going to go down to 1010.

If we pick the middle figure for this yeast attenuation, an FG of 1016 seems to be the expected result: 70 - 16 / 70 x 100 = 77% attenuation. So maybe leave it a bit longer?

 

[DominicRL]

That is extremely helpful thank you, I was wondering if 800g blended fruit addition may also have added a few gravity points. My plan was to leave for another week so hopefully we can get down to the 1.016 you’ve flagged above - really useful to know those calculations as well, will make a note in my brewing notebook! I’ll let you know how I get on (and apologies if this has posted twice I’m having some issues posting), cheers, Dominic!

 

[DominicRL]

As you know I don't brew so wondered how a slightly high FG effects beer in wine making a slightly high FG would mean it was a little sweet so still drinkable.

It will yes, though I’m not too worried with a milkshake ipa, a little on the sweet side should hopefully be ok!

 

[dmtaylor]

Did you use any lactose in this recipe? Lactose is very likely in any milkshake style beer, and lactose is not fermentable. If you used more than a few hundred grams of lactose, the fermentation is almost certainly complete, it will never get much lower than 1.020.

 

[DominicRL]

I did yes, 480g! I’ve never heard this before, though the recipe which came from David Heath suggested I should get an FG of 1.010, I’ve never gone wrong with his recipes so far, do you think he’s made a mistake here, or maybe fermentation is just going to be slower because of the lactose? Best, Dominic

 

[DominicRL]

Apologies minor error, he had an OH of 1.062 and an FG of 1.012 - given my higher start of 1.070 I think I should be aiming (as suggested by others above) for around 1.016? D

 

[dmtaylor]

Apologies minor error, he had an OH of 1.062 and an FG of 1.012

Those numbers are full of ****. Sounds like a poor recipe. I know you all love David Heath but I don't know him from Adam. He's made a mistake here.

 

[DominicRL]

Those numbers are full of ****. Sounds like a poor recipe. I know you all love David Heath but I don't know him from Adam. He's made a mistake here.

Ok that’s good to know - I guess the expected FG is probably a result of different brewing softwares not picking up lactose? I use the Grainfather app and couldn’t find a way to add in other than essentially as ‘misc’! Thanks again for your help, Dominic

 

[prog99]

This one?
https://www.brewersfriend.com/homebrew/recipe/view/451695/milk-shake-ipa-brew-grainfather

 

[Sadfield]

Those numbers are full of ****. Sounds like a poor recipe. I know you all love David Heath but I don't know him from Adam. He's made a mistake here.

Agree. There's also a lot of fruit in it, which would thin it out, though. This recipe looks wrong on many levels.

 

[DominicRL]

This one?
https://www.brewersfriend.com/homebrew/recipe/view/451695/milk-shake-ipa-brew-grainfather

No a different one, it’s at this link:

 

[Sadfield]

It appears that the FG and abv would be correct if the Lactose was substituted with fermentable sugar.

I think you got ~90% efficiency and the FG to be expected with that much Lactose.

 

[DominicRL]

Ah very interesting, so the recipe is likely incorrect because the software DH used could have classed lactose as fermentable sugar (or didn’t consider it at all)? I must admit my first go brewing with lactose has baffled me - you would’ve have thought five years in an ice cream factory would’ve helped. I’ll keep in mind in future to expect higher OG/FG when it’s included (though my ABV seems to be correct so that’s something, unless the higher gravity is a false positive of course), many thanks!