Advice on missed OG targets

Get advice on making beer from raw ingredients (malt, hops, water and yeast)
User avatar
FutureBrewer
Piss Artist
Posts: 203
Joined: Thu Aug 12, 2010 11:04 am
Location: Kings Heath, Birmingham

Advice on missed OG targets

Post by FutureBrewer » Wed Oct 04, 2017 11:26 am

Hi all,

I’m back to brewing after a few years. I’ve made three brews in quick succession and each time I’ve totally missed my OG target by a large margin.

#1 Target: 1.044 – Actual: 1.030*
#2 Target: 1.040 – Actual: 1.031
#3 Target: 1.054 – Actual: 1.045

In the third brew, I even upped the grain bill by 5% but I still missed by a mile.

I’m keeping it simple – no water treatment besides a campden tablet. The water comes
through an inline water filter. There’s nothing added to the mash (besides grain and water).

I’m batch sparging and hitting my strike temp (*besides a cock-up on the first one when I added the mash and top-up water at the start of the mash! We can probably discount this one…) Also, the mash tun is holding temperature within a degree or so after 90 mins.

I’m not knowingly doing anything different to how I used to brew and, back then, I was
generally within a few points. Also, I’m using the same kit.

Any advice for this weekend’s brewday?

Cheers,
FB.


Sent from my iPhone using Tapatalk
Me Man. Me Make Beer.

User avatar
keith1664
Lost in an Alcoholic Haze
Posts: 611
Joined: Mon Oct 04, 2010 8:54 pm
Location: Norwich

Re: Advice on missed OG targets

Post by keith1664 » Wed Oct 04, 2017 11:44 am

Have you worked out your actual efficiency, 75-80 is usual.
In or near Norwich? Interested in meeting up monthly to talk and drink beer? PM me for details.

User avatar
FutureBrewer
Piss Artist
Posts: 203
Joined: Thu Aug 12, 2010 11:04 am
Location: Kings Heath, Birmingham

Re: Advice on missed OG targets

Post by FutureBrewer » Wed Oct 04, 2017 11:56 am

keith1664 wrote:Have you worked out your actual efficiency, 75-80 is usual.
It was a while ago, but I’d calculated it to around 70 - 75...

I’m on same kit and brewing recipes from Wheeler’s BYO - ones that I’ve already done previously with no adjustments. Usually hitting within a point or so, sometimes slightly higher, sometimes slightly lower.

Cheers,
FB.


Sent from my iPhone using Tapatalk
Me Man. Me Make Beer.

Rhodesy
Lost in an Alcoholic Haze
Posts: 678
Joined: Wed Dec 10, 2014 2:09 pm
Location: Glasgow

Re: Advice on missed OG targets

Post by Rhodesy » Wed Oct 04, 2017 12:20 pm

What software are you using to calculate your OG? Also is it possible that your water volumes are out?

If you can post a recipe and volumes that may help?

User avatar
FutureBrewer
Piss Artist
Posts: 203
Joined: Thu Aug 12, 2010 11:04 am
Location: Kings Heath, Birmingham

Re: Advice on missed OG targets

Post by FutureBrewer » Wed Oct 04, 2017 12:29 pm

Rhodesy wrote:What software are you using to calculate your OG? Also is it possible that your water volumes are out?

If you can post a recipe and volumes that may help?
No software - just looking at the expected OG in the recipe book and using a hydrometer at the end of cooling to pitching temp...

The collected batch volumes are correct and also evaporation during boil calculated correctly to leave 19L in fermenter.

I’m using same recipes and methods I’ve previously used, but just way out on targets.

Not able to post recipe at the mo ‘cos I’m at work - the last one was Fullers ESB from
BYO, and I used the batch sparge calculator from this site (as I’ve always done..)

When I’m back home I’ll post the results of calculator.

Thanks for the help so far! :)


Sent from my iPhone using Tapatalk
Me Man. Me Make Beer.

Rhodesy
Lost in an Alcoholic Haze
Posts: 678
Joined: Wed Dec 10, 2014 2:09 pm
Location: Glasgow

Re: Advice on missed OG targets

Post by Rhodesy » Wed Oct 04, 2017 12:51 pm

Have you checked your hyrdometer at 20c with water to see if it still reads 1.000?

User avatar
FutureBrewer
Piss Artist
Posts: 203
Joined: Thu Aug 12, 2010 11:04 am
Location: Kings Heath, Birmingham

Re: Advice on missed OG targets

Post by FutureBrewer » Wed Oct 04, 2017 12:52 pm

Rhodesy wrote:Have you checked your hyrdometer at 20c with water to see if it still reads 1.000?
Yes, and it does.


Sent from my iPhone using Tapatalk
Me Man. Me Make Beer.

super_simian
Piss Artist
Posts: 281
Joined: Thu Sep 22, 2011 10:11 am

Re: Advice on missed OG targets

Post by super_simian » Wed Oct 04, 2017 1:23 pm

Sorry if these questions seem daft but;
  • Are you using fresh grain?
  • Are you crushing it yourself?
  • Is your scale accurate?
  • Is your thermometer accurate?

MTW
Drunk as a Skunk
Posts: 905
Joined: Thu Feb 13, 2014 9:04 pm
Location: Just outside Scarbados

Re: Advice on missed OG targets

Post by MTW » Wed Oct 04, 2017 1:40 pm

Filtered water. Low calcium?
Busy in the Summer House Brewery

User avatar
FutureBrewer
Piss Artist
Posts: 203
Joined: Thu Aug 12, 2010 11:04 am
Location: Kings Heath, Birmingham

Re: Advice on missed OG targets

Post by FutureBrewer » Wed Oct 04, 2017 2:05 pm

super_simian wrote:Sorry if these questions seem daft but;
  • Are you using fresh grain?
  • Are you crushing it yourself?
  • Is your scale accurate?
  • Is your thermometer accurate?
Not daft at all :)

Grain is fresh - 25kg sack of Crisps Maris Otter bought end of August.

Not crushing myself (see above).

Scales are accurate as far as I know - Salter digital scales. New batteries, but same ones I used to use when brewing a few years back.

Thermometer accurate as far as I know Thermapen with fold out probe - new batteries and same as used previously.

Cheers,
FB.




Sent from my iPhone using Tapatalk
Me Man. Me Make Beer.

User avatar
FutureBrewer
Piss Artist
Posts: 203
Joined: Thu Aug 12, 2010 11:04 am
Location: Kings Heath, Birmingham

Re: Advice on missed OG targets

Post by FutureBrewer » Wed Oct 04, 2017 2:06 pm

MTW wrote:Filtered water. Low calcium?
Hmmm - should I just give it a go with water straight from the tap instead of the filtered..?


Sent from my iPhone using Tapatalk
Me Man. Me Make Beer.

chefgage
Hollow Legs
Posts: 499
Joined: Mon Mar 16, 2015 10:37 am

Re: Advice on missed OG targets

Post by chefgage » Wed Oct 04, 2017 2:27 pm

Does it give an expected pre boil gravity reading in the recipe book or have you taken any pre boil gravity readings

Bigbud78
Piss Artist
Posts: 107
Joined: Fri Nov 25, 2016 2:32 pm
Location: Manchester

Re: Advice on missed OG targets

Post by Bigbud78 » Wed Oct 04, 2017 2:33 pm

I'd look at your volumes as well, I've found an extra litre of water pre boil is a drop of about 2 gravity points.

User avatar
vacant
Even further under the Table
Posts: 2018
Joined: Mon Aug 20, 2007 5:39 pm
Location: downstairs
Contact:

Re: Advice on missed OG targets

Post by vacant » Wed Oct 04, 2017 2:34 pm

Is the recipe in US gallons?
I brew therefore I ... I .... forget

User avatar
FutureBrewer
Piss Artist
Posts: 203
Joined: Thu Aug 12, 2010 11:04 am
Location: Kings Heath, Birmingham

Re: Advice on missed OG targets

Post by FutureBrewer » Wed Oct 04, 2017 2:49 pm

chefgage wrote:Does it give an expected pre boil gravity reading in the recipe book or have you taken any pre boil gravity readings
No - recipe book is Graham Wheeler’s Brew Your Own British Real Ale. It lists OG, mash schedule, boil time, final gravity, alcohol content, bitterness units and colour.

I’ve never taken a pre boil gravity reading... I batch sparge and (back in the day) would generally hit my target...

Is this something I should be doing as a matter of course..?


Sent from my iPhone using Tapatalk
Me Man. Me Make Beer.

Post Reply