Og Off The Mark

[BakeryHill]

I'm currently perfecting an American Pale Ale recipe put together by Craft Brewer as an introduction to BIAB. I'm onto my 3rd brew (1st and 2nd were a hit with friends!) but I'm now paying more attention to detail to perfect it and one thing I've done is finally measure OG. The BeerSmith2 recipe says it should be 1.051 but when measured yesterday it was only 1.042.

Whilst numbers are numbers and generally only used as a guide, I'm interested to know what could be the cause of a lower than expected OG and how I can hit the target?

Don't ask me why I didn't measure the other two brews - the answer is quite embarrassing...

 

[manticle]

Could be a bundle of things.

Firstly what was the temp of the brew when you measured it? Heat will give a lower reading which needs to be corrected using charts etc.

 

[BakeryHill]

Could be a bundle of things.

Firstly what was the temp of the brew when you measured it? Heat will give a lower reading which needs to be corrected using charts etc.

Just under 30 on it's way to 20 for yeast pitching. I read that most hydrometers are calibrated for around 25c so I didn't think I was far off it.

 

[stux]

Most that I've seen are calibrated at 20C

1.042 at 30C = 1.045 at 20C according to BeerSmith 2.

That gets you some of your missing extract

20L at 1.052 diluted to 23L is 1.045... so if you added water that would account for some missing OG

Alternatively, it could just be as simple as you didn't get the efficiency from the grain your were expecting, or you left a lot more wort behind in your pot, etc.

When you doing your BIAB measure your gravity at pre-boil and post-boil. Measure volume then to.

Just as your wort starts to boil scoop out 250ml or so with a glass jar or something, and take the volume measure. (I use a ruler and some math ). Put aside the 250ml to cool to about 40C, then do your gravity reading, and return the wort to the boil.

You can repeat the same process at flameout, but don't return the wort, just take a taste of your cooled sample, or perhaps add it to your kettle dregs for starter purposes

That will allow you to calculate your mash efficiency and double check it given the original weight in grain (which was?)

The efficiencies from both measurements (corrected to 20C) should be approximately equal.

Then if you know how much trub you left behind in your kettle... you can work out exactly what you have in your fermenter.

If you're OG is higher than you were expecting you can add more water to the fermenter, if it was lower, then you get weaker beer

Next time you can compensate in your recipe for your actual mash efficiency / trub percentages. Its better to underestimate efficiency, than to over-estimate, as you can always dilute, but its hard to concentrate the wort in the fermenter

 

[BakeryHill]

Most that I've seen are calibrated at 20C

1.042 at 30C = 1.045 at 20C according to BeerSmith 2.

That gets you some of your missing extract

20L at 1.052 diluted to 23L is 1.045... so if you added water that would account for some missing OG

Alternatively, it could just be as simple as you didn't get the efficiency from the grain your were expecting, or you left a lot more wort behind in your pot, etc.

When you doing your BIAB measure your gravity at pre-boil and post-boil. Measure volume then to.

That will allow you to calculate your mash efficiency and double check it given the original weight in grain (which was?)

The efficiencies from both measurements (corrected to 20C) should be approximately equal.

Then if you know how much trub you left behind in your kettle... you can work out exactly what you have in your fermenter.

If you're OG is higher than you were expecting you can add more water to the fermenter, if it was lower, then you get weaker beer

I think you're right there about adding water - had to add a little at the end to make up the full amount.

Add in a few of the other factors and that's probably where my missing OG is.

This brew didn't go as smoothly as the 2nd as I was trying a few new things. From my calcs it'll be a 4.5% ABV rather than the 4.8% originally specified. I can live with that.

 

[stux]

Every boil over you lose a pint

 

[BakeryHill]

Every boil over you lose a pint

More like every spill from trying to strain the wort, you lose a pint...

 

[RdeVjun]

More like every spill from trying to strain the wort, you lose a pint...

Pelletised hops or plugs/ whole flowers?

 

[BakeryHill]

Pelletised hops or plugs/ whole flowers?

Pellets

 

[RdeVjun]

Yeah, I thought so. Use at least some plugs or whole flowers in the boil is my advice, it will strain far better when using a sieve or colander and pouring the lot through. At least I guess that's what you're doing?

 

[thedragon]

RdeVjun

It is necessary to strain, or is it OK to tip the chilled wort (including the residue from the hop pellets) straight in to the fermenter? If it makes any difference to the answer, I don't rack to secondary, but bottle directly from the fermenter.

Daniel

Yeah, I thought so. Use at least some plugs or whole flowers in the boil is my advice, it will strain far better when using a sieve or colander and pouring the lot through. At least I guess that's what you're doing?

 

[RdeVjun]

Good question thedragon. Today's wisdom is roughly that hot break = bad, cold break = benign, while hops debris is largely moot considering the dry hopping that goes on these days, albeit that it usually isn't boiled beforehand. However, I do strain all of the wort through a colander, but I do use at least some whole or plug hops in the boil and you'd be surprised how effective that is at straining as opposed to just blocking up completely. Not all of it by a long shot, but certainly a good deal of it.
But, to answer your question directly, while the cold break and hops debris might perhaps be considered 'permissible', all of the hot break would concern me. However, I'm a pragmatist- so tell me, if you've done that and have tried the beer (nb. it is not at all unheard of), the most important thing is how are you finding it? :icon_cheers:

Edit: Apologies to OP for subverting the thread.

 

[BakeryHill]

Good question thedragon. Today's wisdom is roughly that hot break = bad, cold break = benign, while hops debris is largely moot considering the dry hopping that goes on these days, albeit that it usually isn't boiled beforehand. However, I do strain all of the wort through a colander, but I do use at least some whole or plug hops in the boil and you'd be surprised how effective that is at straining as opposed to just blocking up completely. Not all of it by a long shot, but certainly a good deal of it.
But, to answer your question directly, while the cold break and hops debris might perhaps be considered 'permissible', all of the hot break would concern me. However, I'm a pragmatist- so tell me, if you've done that and have tried the beer (nb. it is not at all unheard of), the most important thing is how are you finding it? :icon_cheers:

Edit: Apologies to OP for subverting the thread.

No problems with hijacking the thread. It was a question I had as I was straining the wort into the fermenter. I didn't for my first batch and is was cloudy (think Coopers Pale Ale) and for my second I did and it was much clearer. I was just trying to replicate through a stocking and it spilt.

 

[kelbygreen]

well hot break is your most consern. But cold break it best not in your fermenter to! If you want to make better beer, Then you have to heat to wort enough to make hot break and must cool fast enought to make cold break (they say try to cool to pitching temp within 30 mins). I have done this once and sure I have only done it once in my first double batch but I got 5lts of trub and usually get 1.5lts max out of single but leaving it to cool in the pot by itself. The wort into the fermenters where alot clearer then they where without chilling fast. I have always had chill has (but never added anything) so will see when I get home and keg if quick chilling helps

 

[RdeVjun]

No sweat BakeryHill, its a bummer the stocking split!
Pouring all of the wort through a strainer of some sort has been considered questionable, that's fair enough as break material (certainly hot break but also cold to perhaps a lesser extent) has also been on the nose, while straining does let a proportion of break through into the fermenter. However, using some whole hops and pouring the lot through a sieve or colander does capture quite a lot of it (I've some photos on a camera, just waiting to get it back) and in my view, there's enough break trapped for it to be effective, but also a simple means to empty small kettles (i.e. <20L).
If there's any doubt, perhaps recent comp results would be useful as an indicator. Recently I entered six beers strained this way in BABBs Annual, that's the maximum permitted, however every beer scored a medal (two silver, four bronze), plus a first and two third places. Pretty sure that either BABBs is a crap comp to enter , or the consistency of the results indicate the method is sound. QABC wasn't quite as fertile territory, just the one silver, three bronze out of eight entered, however one beer is en route to the Nats- still can't complain about those results! B)
So to wrap up, I'd certainly recommend straining break out of your wort. Whole/ plug hops can be very helpful in achieving this, however, as many brewers have found, pelletised hops can make this an order of magnitude more difficult and just not as effective.
Pardon the digression and self- promotion, but I hope this helps! :icon_cheers:

Edit: And good wort recovery will help keep your efficiency up through less loss to trub too.

 

[BakeryHill]

No sweat BakeryHill, its a bummer the stocking split!
Pouring all of the wort through a strainer of some sort has been considered questionable, that's fair enough as break material (certainly hot break but also cold to perhaps a lesser extent) has also been on the nose, while straining does let a proportion of break through into the fermenter. However, using some whole hops and pouring the lot through a sieve or colander does capture quite a lot of it (I've some photos on a camera, just waiting to get it back) and in my view, there's enough break trapped for it to be effective, but also a simple means to empty small kettles (i.e. <20L).
If there's any doubt, perhaps recent comp results would be useful as an indicator. Recently I entered six beers strained this way in BABBs Annual, that's the maximum permitted, however every beer scored a medal (two silver, four bronze), plus a first and two third places. Pretty sure that either BABBs is a crap comp to enter , or the consistency of the results indicate the method is sound. QABC wasn't quite as fertile territory, just the one silver, three bronze out of eight entered, however one beer is en route to the Nats- still can't complain about those results! B)
So to wrap up, I'd certainly recommend straining break out of your wort. Whole/ plug hops can be very helpful in achieving this, however, as many brewers have found, pelletised hops can make this an order of magnitude more difficult and just not as effective.
Pardon the digression and self- promotion, but I hope this helps! :icon_cheers:

Edit: And good wort recovery will help keep your efficiency up through less loss to trub too.

The batch in the fermenter now is the 2nd I've strained (though the result this time was less than satisfactory than the 1st as has already become apparent!). On my 2nd batch (1st time straining) the amount of "crap" (is that the right word?) in the bottom of the fermenter at bottling time was considerably less and my resultant beer was much clearer. I'm not sure if these two observations are related but one would think it's plausible.

The reason I spilt some this time was because I used a different method (stocking in a strainer as opposed to just through a stocking - unworn by my wife of course!) to the first time and in hindsight, I shouldn't have stuffed around with what worked.

Your comp results are interesting - my next step is to enter a comp to get some feedback. Relying on friend's comments while they are drinking my beer freely is probably not a reliable gauge, though I must say I'm happy with my 2nd batch which is the 2nd time I've ever brewed. Another step is to join a club, preferably to the north of Brisbane, but having time to attend meetings and weekends is difficult for me. I'm sure I'd learn a lot more watching others and their methods.

 

[RdeVjun]

I know what you mean about reliable feedback, it is all nice and fuzzy for someone to comment that they like your beer, but when you get interested in technical aspects of brewing, albeit that those sorts of comments are quite rewarding, its probably not really what you are after at this point. However, local brewers should be more than willing to help with feedback on your beer, I'll drop you a line when I'm in Brisbane next (most likely this coming week).
I'd also recommend getting along to a homebrew club and handing around a bottle or two for feedback, it is really valuable to help iron out technical issues and finer details. The Brisbane clubs are BABBs on the southside, PUBS on the north (Pine Rivers), even the new Ipswich club would welcome new prospective members I'd say, and I'm fairly sure all of them would be more than willing to have new members sign up. Just spending a few hours chatting with other brewers is quite valuable too, you can pick up all sorts of useful information and advice, I know I have.
Not sure about other clubs, however BABBs Minicomp is also excellent for feedback, as a visitor you are permitted to submit at least one beer (or is it two?) and it is judged blind according to BJCP style guidelines by a table of fellow brewers, thing is that only members are eligible for prizes. Nevertheless, the technical feedback is quite valuable to novice brewers, while the monthly categories can be helpful in planning a bit of a brewing schedule (eg. this month is Lager/ Pilsner- I'd better remember to keep one!).
Some clubs are more socially- oriented with planned events and outings, that's fine, but I sought out a technically- focussed club as that was what I really wanted to participate in, but we do allow ourselves to have a little bit of fun at BABBs too. :beer:

As a general observation, kettle trub settling at the bottom of the fermenter is a good thing- its far better off there than in your beer! Preventing it entering there in the first place is of course more desirable, however my advice is don't be too alarmed if some does, but I'm sensing that you've found that out already! Fermentation trub i.e. yeasty slurry is another issue altogether, there's not much to be done about that forming however again, there's ways of preventing it ending up in the final packaged beer, eg. secondary, cold conditioning, flocculants, etc.

Hope this helps! :icon_cheers:

 

[Janelle Kerr]

Hi, there are also the other clubs, Lockyer Valley and St Arnolds in Towoomba, and BBC. The new Ipswich club I know has a few good brewers.
As I am the secretary of the QAAWBG, I usually talk to the secretaries reasonably regularly.

We had a great State comp this year, and the Presentation Night was really good. Went to the Yamanto Tavern first for Craft Beer on tap. It's a really good opportunity for the clubs to get together and mingle.

Finally won QAAWBG Champion Beer this year, was wrapped as it has taken quite a few years, and the quality of brews was brilliant! (always handy to be the steward, you get to take them home)
Sent my 5 best beers to Adelaide for the ANAWBS, only 3 made it. My Champion, and the best of my beers ( I found at the back of the shelf ) were the ones that smashed! the other three were really just space fillers.

Check out the www.queenslandbrewers.com.au site for all dates etc.of competitions in 2012.... Watch this space because next year is going to be a big one for the Championships in Qld.

So that's a long drive to the BABB meetings....... Lucky ours is close, especially on mini-comp nights! they're always a good night. Informative and refreshing!!

 

[Janelle Kerr]

Good question thedragon. Today's wisdom is roughly that hot break = bad, cold break = benign, while hops debris is largely moot considering the dry hopping that goes on these days, albeit that it usually isn't boiled beforehand. However, I do strain all of the wort through a colander, but I do use at least some whole or plug hops in the boil and you'd be surprised how effective that is at straining as opposed to just blocking up completely. Not all of it by a long shot, but certainly a good deal of it.
But, to answer your question directly, while the cold break and hops debris might perhaps be considered 'permissible', all of the hot break would concern me. However, I'm a pragmatist- so tell me, if you've done that and have tried the beer (nb. it is not at all unheard of), the most important thing is how are you finding it? :icon_cheers:

Edit: Apologies to OP for subverting the thread.

I agree. I always strain my beer. I am really fussy about cloudy beer. Gets strained from the boiler to the fermenter, then strained into secondary fermenter. Usually use gelatin at approx. 48 hrs before the end of the 1st. The secondary ferm. is always clear, but if a bit cloudy it will settle over a couple of days.

Unless it is supposed to be cloudy of course.
However, there is never any white sludge at the bottom of my beers, which is the whole point of it all....

 

[Janelle Kerr]

I agree. I always strain my beer. I am really fussy about cloudy beer. Gets strained from the boiler to the fermenter, then strained into secondary fermenter. Usually use gelatin at approx. 48 hrs before the end of the 1st. The secondary ferm. is always clear, but if a bit cloudy it will settle over a couple of days.

Unless it is supposed to be cloudy of course.
However, there is never any white sludge at the bottom of my beers, which is the whole point of it all....

Oh, and I just use black and Gold chux wipes. They are brilliant for the job. Pegged onto a colander which sits nicely in the top.