WAY OFF with Brewer's Friend OG reading...Twice!

[phildo79]

Hi guys

Wondering if any of you have any theories on this one. I use Brewer's Friend as my online recipe builder/calculator and I normally hit my target OG or at least get to within 3 points. But I have just brewed the same recipe in succession (8.3% stout) and have missed the OG by a massive amount. I was 15 points under on Sunday and something similar when I brewed the same beer a month ago. Target OG was 1.079 and I hit 1.064. I waited until the wort had cooled to below 30C and used a refractometer. Same way the first time. I popped in an iSpindel but because I ferment in a keg, the signal doesn't always get out and I have no reading from before it started fermenting. However, I did get a reading a month ago and it told me the OG was 1.069 which was 10 points out. However, I need to recalibrate my iSpindel so I wouldn't put too much faith in that reading. It isn't massively out but it is out. I really only bought the thing to determine stuck ferments etc.

Going by the iSpindel last time, it fermented well below the target FG of 1.020 and produced a beer in the region of 8.3% so I wasn't concerned. But the exact same thing is happening again. I don't foresee this beer stopping at 1.020 and I really hope is doesn't. But why is Brewer's Friend so far out with this equation when it has always been very close in the past?

Confused!
Cheers

 

[jayk34]

What was the recipe ? Did you have oats in this one ? I have had this on several occasions when using oats in a recipe

 

[Sadfield]

What has been your experience with brewing other beers of this strengh? Did you hit the target OG?

I always knock my Brewhouse efficiency back when doing anything above 7%*. It's hard to extract sugar from grain with highly sugary water. Like adding more and more sugar to water, at some point it stops dissolving.

*Except for Trappiste style beers when adding sugar to the kettle.

 

[RoomWithABrew]

These issues are always minefields, what kit are you using?
What ingredients, How much water, did you treat the water, did you check the mash temperature, did you stir the mash, did you check the mash pH, did you sparge, how much, how warm, what was the gravity pre boil. What were the volumes at each stage, was your final volume on target. Was it the same crush of grain each time.
I got into these worries and when I asked for help found I didn't have a king clue about what to collect, record etc. found out I wasn't collecting data enough to give myself or anyone else a chance to guide me.

Can you throw us a few more crumbs please. Ideally your mash efficiency and pre boil gravity and volumes would be good things for us to look at.

 

[phildo79]

What was the recipe ? Did you have oats in this one ? I have had this on several occasions when using oats in a recipe

Yeah, it had oats.

 

[phildo79]

What has been your experience with brewing other beers of this strengh? Did you hit the target OG?

I always knock my Brewhouse efficiency back when doing anything above 7%*. It's hard to extract sugar from grain with highly sugary water. Like adding more and more sugar to water, at some point it stops dissolving.

*Except for Trappiste style beers when adding sugar to the kettle.

I would say yes but this is my strongest AG beer so it's new ground.

 

[phildo79]

https://www.brewersfriend.com/homebrew/recipe/view/704573/founders-breakfast-stout#

 

[phildo79]

That should have most of the info asked for.
NB: there was no sparge and my equipment is a 35L digiboil

 

[Sadfield]

I would say yes but this is my strongest AG beer so it's new ground.

Higher than normal grain bill and no sparge will hit efficiency. High gravity wort getting thrown out with a bigger bulk of used grain.

https://beerandwinejournal.com/efficiency-gravity/

 

[phildo79]

Great read. I deliberately didn't sparge for fear of diluting the wort. Which was only amplified when I checked the pre boil gravity a month ago.

 

[Sadfield]

Yes, it does a good explanation of where/how the loss occurs, although I wouldn't relish 4 hour boil to get 11 gallons down to 5, not that it'd fit in my kettle anyway. Take the efficiency hit and chuck more grain at it.

 

[Eskdale]

Hi guys

Wondering if any of you have any theories on this one. I use Brewer's Friend as my online recipe builder/calculator and I normally hit my target OG or at least get to within 3 points. But I have just brewed the same recipe in succession (8.3% stout) and have missed the OG by a massive amount. I was 15 points under on Sunday and something similar when I brewed the same beer a month ago. Target OG was 1.079 and I hit 1.064. I waited until the wort had cooled to below 30C and used a refractometer. Same way the first time. I popped in an iSpindel but because I ferment in a keg, the signal doesn't always get out and I have no reading from before it started fermenting. However, I did get a reading a month ago and it told me the OG was 1.069 which was 10 points out. However, I need to recalibrate my iSpindel so I wouldn't put too much faith in that reading. It isn't massively out but it is out. I really only bought the thing to determine stuck ferments etc.

Going by the iSpindel last time, it fermented well below the target FG of 1.020 and produced a beer in the region of 8.3% so I wasn't concerned. But the exact same thing is happening again. I don't foresee this beer stopping at 1.020 and I really hope is doesn't. But why is Brewer's Friend so far out with this equation when it has always been very close in the past?

Confused!
Cheers

I would be interested to know what efficiency you dialled into Brewers Friend? If you have a 75% efficiency on a regular ABV brew and you then programme a brew with a higher grain bill and no sparge, as Sadfield says your efficiency will fall. Try dialling 55 or 60% and you will see to reach the same OG the grain bill will be higher.

Emma

 

[RoomWithABrew]

Some info, thank you, but I can't see the grain bill or liquid volumes. I use brewfather so can't login.

Can you post the information please?

 

[foxy]

I do full volume mash with no sparge. You have to play around with your efficiency numbers to match the Brewers Friend a finer grain crush will lift the efficiency somewhat. It will be somewhere between 55 to 65 % efficiency, that is after adding the extra grain to hit the numbers. I can't see flaked oats making a difference unless you aren't using pre-gelatinised oats.

 

[phildo79]

 

[Sadfield]

Too late now for @phildo79, however a stock of DME is handy thing to have when attempting high abv AG brews for the first time.

 

[Eskdale]

I see you had 72% BHF in your program, if you bring that percentage down until it corresponds with the OG you got then next time you will know you aren't going to be far off.

Emma

 

[The-Engineer-That-Brews]

The other thing that will change with a lot more grain than usual is that the pH will drop more - so if you’re already adding acid then I guess you might find that the mash pH was a bit too low for the amylase enzymes to work well

 

[phildo79]

Didn't add acid to this one. I actually scaled this recipe down by 20% in order for my equipment to handle it. And it still maxed it out. Ultimately the beer fermented down enough to hit the target FG almost bang on, so I am probably not going to tinker with the process that much. Especially since the beer turned out so well.

But I have come to the realisation that I need a bigger boiler. Not by much but perhaps scale up from 35L to 50L. Might look at getting an all in one system.