Advice on missed OG targets

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FutureBrewer
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Re: Advice on missed OG targets

Post by FutureBrewer » Wed Oct 04, 2017 2:50 pm

Bigbud78 wrote: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.
Collected volumes are correct according to the batch sparge calculator...


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Re: Advice on missed OG targets

Post by FutureBrewer » Wed Oct 04, 2017 2:51 pm

vacant wrote:Is the recipe in US gallons?
No. 19 Litres - Graham Wheeler’s Brew Your Own British Ale.


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Re: Advice on missed OG targets

Post by chefgage » Wed Oct 04, 2017 3:10 pm

FutureBrewer wrote:
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..?


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It might help, although if it does not show it in the recipe i suppose you have nothing to compare it to. It was just i had a few problems with hitting the correct OG to start with and someone sugested taking lots of readings along the way including volume and temperature to see at what point the problem occured.

In my case it was not stirring after batch sparging before taking a pre-boil gravity reading (it was the pre-boil figure i was concerned with). And then a combination of incorrect volume calculations based on the beersmith software i was using.

Are you relying on the markings on the side of your vessel such as what is stamped on plastic fermenters. I have found these to be off by quite a bit.

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Re: Advice on missed OG targets

Post by FutureBrewer » Wed Oct 04, 2017 3:19 pm

chefgage wrote:
FutureBrewer wrote:
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..?


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It might help, although if it does not show it in the recipe i suppose you have nothing to compare it to. It was just i had a few problems with hitting the correct OG to start with and someone sugested taking lots of readings along the way including volume and temperature to see at what point the problem occured.

In my case it was not stirring after batch sparging before taking a pre-boil gravity reading (it was the pre-boil figure i was concerned with). And then a combination of incorrect volume calculations based on the beersmith software i was using.

Are you relying on the markings on the side of your vessel such as what is stamped on plastic fermenters. I have found these to be off by quite a bit.
Ah, I get ya. I’ll record these readings on my next brewday for reference.

As mentioned, I’m using my original kit - I generally used to hit target with it. This includes collecting batches in self-calibrated plastic fermenter buckets - weighing out liquid in litre intervals and marking on the bucket. Same goes for adding sparge and top up, using a notched (in litre intervals), long plastic spoon.

Cheers,
FB.


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Re: Advice on missed OG targets

Post by chefgage » Wed Oct 04, 2017 3:24 pm

Another point. You mention top up water. Is this topping up the fermenter after transfering from the boil kettle. If so are you making sure you stir in the topped up water before taking a gravity reading.

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Re: Advice on missed OG targets

Post by FutureBrewer » Wed Oct 04, 2017 3:39 pm

chefgage wrote:Another point. You mention top up water. Is this topping up the fermenter after transfering from the boil kettle. If so are you making sure you stir in the topped up water before taking a gravity reading.
Nope - topping up is just the batch water... mash, top up, drain, 2nd batch, drain.

I never add to the fermenter except for the post boil wort... I’d rather have a strong beer mistake than a weak ‘un ;)


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Re: Advice on missed OG targets

Post by Jambo » Wed Oct 04, 2017 3:47 pm

Long shot but have you moved house since you were last brewing (different water)?

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Re: Advice on missed OG targets

Post by MTW » Wed Oct 04, 2017 3:54 pm

FutureBrewer wrote:
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..?


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It's definitely a base I'd want to cover. That and the suggestion you take a pre-boil gravity and check all your calibrations, volumes, mash thermometer, etc etc.
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Re: Advice on missed OG targets

Post by FutureBrewer » Wed Oct 04, 2017 3:56 pm

Jambo wrote:Long shot but have you moved house since you were last brewing (different water)?
Yes, I have :)

I reckoned on using the water from the inline filter for a neutral base...

I wanted to keep it simple for first brews (simple recipes I’ve done before and no water treatment) but maybe I should’ve checked mash pH..? Added calcium..?



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Re: Advice on missed OG targets

Post by FutureBrewer » Wed Oct 04, 2017 3:58 pm

MTW wrote:
FutureBrewer wrote:
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..?


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It's definitely a base I'd want to cover. That and the suggestion you take a pre-boil gravity and check all your calibrations, volumes, mash thermometer, etc etc.
Righto. Keeping it simple just got complicated ;)

Cheers,
FB.


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Re: Advice on missed OG targets

Post by chefgage » Wed Oct 04, 2017 7:08 pm

If you suspect the water try tescos ashbeck water. Lots of us use that with no problems.

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Re: Advice on missed OG targets

Post by guypettigrew » Wed Oct 04, 2017 8:22 pm

It's not going to be anything complicated like your water profile. Why? Well, because it won't be! Not to be that far off your intended OG anyway.

This really sounds like a sparge problem, assuming your mash regime is as good as you say.

You always used to batch sparge and you got better extraction. Think hard, really hard, about how you used to do it. Did you stir the mash? How long did you leave it before running off the second and third worts? How much did you drain the mash before adding the new sparge liquor? And, perhaps crucially, how fast was your run off?

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Re: Advice on missed OG targets

Post by FutureBrewer » Thu Oct 05, 2017 9:39 am

guypettigrew wrote:It's not going to be anything complicated like your water profile. Why? Well, because it won't be! Not to be that far off your intended OG anyway.

This really sounds like a sparge problem, assuming your mash regime is as good as you say.

You always used to batch sparge and you got better extraction. Think hard, really hard, about how you used to do it. Did you stir the mash? How long did you leave it before running off the second and third worts? How much did you drain the mash before adding the new sparge liquor? And, perhaps crucially, how fast was your run off?

Guy
Aye - my reckoning would be it’s something I’m doing wrong. I’ll dig out all of my notes from past brews and see if I’m deluding myself..! It won’t be the first time :)

Meanwhile, I’ll read up on batch sparging methods again.

Thanks to all for your help - gotta love JBK!


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Re: Advice on missed OG targets

Post by jonnymorris » Sat Oct 07, 2017 8:52 am

guypettigrew wrote:It's not going to be anything complicated like your water profile. Why? Well, because it won't be!
This strikes me as somewhat dismissive of what could be a potentially significant change to the biggest ingredient, water. I get your point but still think it's worth investigating further.

How far have you moved, across town or to another part of the country?

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Re: Advice on missed OG targets

Post by guypettigrew » Sat Oct 07, 2017 11:07 am

jonnymorris wrote:
Sat Oct 07, 2017 8:52 am
guypettigrew wrote:It's not going to be anything complicated like your water profile. Why? Well, because it won't be!
This strikes me as somewhat dismissive of what could be a potentially significant change to the biggest ingredient, water. I get your point but still think it's worth investigating further.

How far have you moved, across town or to another part of the country?
Agreed, jonnymorris, my comment was rather an over generalisation. But, as the OP is losing 10 gravity points each brew, the reason is much more likely to be a flaw in the process somewhere. The water may contribute, but not much.

The mash and sparge still seem to be the most likely candidates.

Guy

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