Proper Job high FG

[Sutty]

I brewed a "Proper Job" clone 3 weeks+ ago, started at 1064, all seems finished but its at 1020. All my brews have ended higher than expected (only 6 brews so far, all with a grainfather), so this is not entirely unexpected. The others had a lower OG but finished 1014-1016.
Mash was at 66C - though I brewed today and dropped to 64C to see any difference.
Yeast was WLP007 "dry english ale yeast" so should attenuate enough.
My guess is that 66C is too high, maybe my grainfather under-reads the temperature, though it seemed to agree with a thermometer.
Any ideas or suggestions?

 

[GHW]

Mashing at 66 should give you a high amount of fermentable sugars so you should in theory get a lower Fg. it's unlikely the grainfather is measuring lower than actual, so that's probably not the issue.

Also, that's about 68% attenuation, seems low, but not unreasonably. Haven't checked what that yeast should give you, but might be the issue.

Also what is its alcohol tolerance? A 1064 of will give you a high abv, maybe that yeast doesn't like it?

Final thought, was the sort oxygenated enough? If all your brews are finishing high it suggests some systematic problem, and not enough oxygen could the problem...

Hope that helps

 

[JapanBrew]

That's backwards... Higher temp produces more sweet, unfermentables. Lower temps make dry beer. Producing Beta amylase. Beta enzymes just randomly munch at the starch breaking it down randomly. Now with that, you'd think that the alpha enzyme, produced at 68 degrees would ferment better. But thats not the case. When you mash out, a whole other process happens. Those enzymes get smashed.
There's a lot of wiki sites that get real detailed. For me, it's a fun read but bores the hell out of people. At least give it a read to understand what is happening in your mash tun.

 

[Sutty]

Mashing at 66 should give you a high amount of fermentable sugars so you should in theory get a lower Fg. it's unlikely the grainfather is measuring lower than actual, so that's probably not the issue.

Also, that's about 68% attenuation, seems low, but not unreasonably. Haven't checked what that yeast should give you, but might be the issue.

Also what is its alcohol tolerance? A 1064 of will give you a high abv, maybe that yeast doesn't like it?

Final thought, was the sort oxygenated enough? If all your brews are finishing high it suggests some systematic problem, and not enough oxygen could the problem...

Hope that helps

Thanks, but the yeast doesn't really explain it - copied from white labs website:-

WLP007 Dry English Ale Yeast

Clean, highly flocculent, and highly attenuative yeast. This yeast is similar to WLP002 in flavor profile, but is 10% more attenuative. This eliminates the residual sweetness, and makes the yeast well suited for high gravity ales. It is also reaches terminal gravity quickly. 80% attenuation will be reached even with 10% ABV beers.


Aeration was by running the wort down the sides of the corny I fermented in, constantly moving the jet of wort around the sides, then giving it a very thorough shake too. I have wondered about pressurising the corny with pure oxygen then shaking.

 

[HebridesRob]

may we see the recipe?

 

[Sutty]

[FONT=&quot]It was supplied as a kit of grain and hops by BrewUK
[/FONT]
[FONT=&quot]
[/FONT]
[FONT=&quot]
[/FONT]
[FONT=&quot]1 x 3kg Maris Otter Malt
1 x 2.5kg Maris otter
1 x 59g Cascade Hops[/FONT]
[FONT=&quot]1 x 35g Chinook Hops[/FONT]
[FONT=&quot]1 x 66g Willamette [/FONT]
[FONT=&quot]
To make 23 Litres
[/FONT]
[FONT=&quot]Recipe Stats:[/FONT]
[FONT=&quot]O.G. 1056
F.G. 1014
ABV 5.5%

[/FONT]
[FONT=&quot]Mash Schedule:[/FONT]

[FONT=&quot]Standard:[/FONT]
[FONT=&quot]Mash 90mins 66c with 2.5L of water/kg of malt. [/FONT]
[FONT=&quot]Sparge with 77c water to collect 26L of Wort. Bring to boil then follow hop schedule.[/FONT]


[FONT=&quot]Hop Schedule:[/FONT]
[FONT=&quot]Total Boil time:90 mins
Start of boil: 10g Chinook and 10g Willamette[/FONT]
[FONT=&quot]30 Mins from end: 13g Cascade, 10g Chinook, 10g Willamette[/FONT]
[FONT=&quot]15 Mins from end: 20g Cascade, 7g Chinook, 20g Willamette[/FONT]
[FONT=&quot]End of boil add balance of hops then cool[/FONT]




[FONT=&quot]With the grainfather I had 18l of strike water, and sparged to 26l, ended with 23l. As with my other brews the OG was higher than predicted - the grainfather seems to have very high efficiency.

[FONT=&quot]It tastes OK[FONT=&quot], maybe a bit sweeter than it should, but its not carbonated at the moment so may taste better once it is.[/FONT][/FONT]
[/FONT]

 

[MyQul]

Did you make a starter for the WLP007

 

[GHW]

What temp did you ferment at? That might slow things down too

 

[HebridesRob]

There's nothing in the recipe that would make one expect the FG to be 1.020. If anything, I'd expect lower than 1.014. The yeast shouldn't be experiencing any issues from the alcohol and should certainly be attenuating more than that. Fact sheet for the yeast...
https://www.whitelabs.com/yeast/wlp007-dry-english-ale-yeast

Is the hydrometer accurate?