# Insane BIAB Efficiency after brewery revamp



## mtb (28/9/16)

There's got to be something I'm missing, so I'm reaching out to you good gentlemen, ladies and LadyBoy to help.
I've just finished mashing/sparging my Adequate Ale 11 recipe and the pre-boil gravity is reading 1.060 at 68L. Anticipating a 70% BH efficiency I was to expect 1.041 pre-boil gravity at ~64L. Dialling these readings into Beersmith tells me that my efficiency is over 100% which is what leads me to believe I've buggered something up, and given I'm full of tasty home brew, this is my first and only assumption.

Things I've done to cross-check my readings;
- tested the hydrometer with tap water; it reads 1.00
- adjusted for wort temperature; it actually read 1.048 at 58deg which works out to 1.061
- confirmed I only used the grains as per the recipe

By "brewery revamp", I mean that I recently got the shits with poor BH efficiency and bought store-cracked grain and built a sparging vessel. Tonight I used that cracked grain and sparging vessel; the sparging vessel is just a fermenter with the top cut off and a bunch of holes drilled in the bottom. After mashout I put the bag in the vessel and top up with sparge water. I sparged with 26L water at 76deg.

Thoughts? Is this just really good mash efficiency? I'd better adjust the hop schedule to suit an IPA instead of Pale Ale at this rate.


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## Rocker1986 (28/9/16)

Is the volume measurement correct? It seems rather impossible to be able to get over 100% extraction from the grains...


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## Lyrebird_Cycles (28/9/16)

There's a mistake somewhere: 1060 is 156 g/l extract, multiply by 68 litres is 10.6 kg, not possible from 11 kg of grain.


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## timmi9191 (28/9/16)

I'll put my hand up and say that I was measured out grain twice. eg 5kg pale, 2 kg wheat, 150g crystal, 2 kg wheat. etc etc.. only realised when took the OG reading and back tracked what was left in my inventory.

Ended up with an 8% cerveza named it el loco.. wasnt too bad actually.

Maybe something similar happening mtb??


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## mtb (28/9/16)

I thought I'd used more grain too, but because this was store-bought, it was in individual 1kg bags. I've just counted out the empty 1kg bags: nine Gladfield Pale Malt, one wheat malt, and I have two half-full Crystal and Munich on my counter. I know I didn't use more than this because I don't even own any other cracked grains, all other grain is whole (I usually crack my own).
Volume is an estimation as it's ~3cm from the lip of my 70L pot, after sparging finished. If it were 60L there'd still be an insane efficiency reading.


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## Danscraftbeer (28/9/16)

I can never get an accurate pre boil gravity. Said it many times before. If I do 5 tests I get 5 different readings at any time through to 30 minutes boiled. still cant get a consistent reading and mostly high suggesting over 100% mash efficiency. So I totally give up on pre boil gravity readings. 
Then to the official OG reading. The ferment will have to be mixed really well for a few minutes and then take a reading for OG.
I have found wort to be extremely confusing to read. Its like it must have currents of sugars or something I don't understand.


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## mtb (28/9/16)

Danscraftbeer said:


> I can never get an accurate pre boil gravity. Said it many times before. If I do 5 tests I get 5 different readings at any time through to 30 minutes boiled. still cant get a consistent reading and mostly high suggesting over 100% mash efficiency. So I totally give up on pre boil gravity readings.
> Then to the official OG reading. The ferment will have to be mixed really well for a few minutes and then take a reading for OG.
> I have found wort to be extremely confusing to read. Its like it must have currents of sugars or something I don't understand.


Yeah that's going to be the real indicator - the BH efficiency. I'm 45min into the boil now so I'll know soon enough. I will take the OG reading from the fermenter.


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## bradsbrew (28/9/16)

How did you take the sample?


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## Rocker1986 (28/9/16)

I'm not sure if I'm understanding this correctly but if you are taking readings at various points all the way through to 30 minutes boiled then of course they will be different due to the water being boiled off. Pre boil SG means just that, pre boil.

Dissolved sugars shouldn't move around in the wort either, once they're dissolved and evenly mixed that's how they stay. They only start to come out of solution if you reach saturation point which requires a hell of a lot more sugar than you'd extract in a grain mash.


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## mtb (28/9/16)

bradsbrew said:


> How did you take the sample?


Poured from the outlet valve into a glass, cooled a little, added to hydrometer tube.




Rocker1986 said:


> I'm not sure if I'm understanding this correctly but if you are taking readings at various points all the way through to 30 minutes boiled then of course they will be different due to the water being boiled off. Pre boil SG means just that, pre boil.
> 
> Dissolved sugars shouldn't move around in the wort either, once they're dissolved and evenly mixed that's how they stay. They only start to come out of solution if you reach saturation point which requires a hell of a lot more sugar than you'd extract in a grain mash.


Haven't taken readings *during *the boil, just before the boil. I am now waiting for the boil to complete so I can chill and take another reading which would be my OG, and then I can calculate my BH efficiency.
Speaking of which, BeerSmith tells me it's flameout..


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## Danscraftbeer (28/9/16)

To add something geeky freeky. I take a sample from my kegmenter after its charged to 5psi with o2 and roll shaken.

Just by 6mm hose on a beer disconnect into test tube.

This done immediately after I roll shake it gets me the true reading. All by estimated design. 
I have forgotten to take that reading sometimes and then took one the next morning and freeked out because it was much lower than expected so I thought I'd bombed out on efficiency big time. But I knew I did it all right! -_- 

I then re mixed the kegmenter again for one minute and took a reading and it was up there were it was supposed to be by design. All good.

Its like the sugars rise in the first 12 hours or something? :unsure: I really don't know but its not really a problem as far as I hit my expected total efficiency. :chug:


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## bradsbrew (28/9/16)

Could be that you have taken a more concentrated sample from first runnings in outlet?


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## mtb (28/9/16)

Nah, I recirculate via that outlet. Also I stirred beforehand


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## mtb (28/9/16)

Well, the OG is 1.049. No clue what prompted the hydrometer to read so high pre-boil... I shit you all not, it read 1.048 pre-boil, with adjustment for temperature, that was 1.061.

Anyway - this is not the story of a magic super-efficient BIAB that I hoped it would be. I adjusted the recipe pre-boil on the assumption that the OG would be far higher so I now have a very bitter (60 IBU) Pale Ale.. hope it doesn't taste too bad, I dumped 250g hops into it :unsure:


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## Rocker1986 (28/9/16)

mtb said:


> Haven't taken readings *during *the boil, just before the boil.


Sorry mate, was referring to this here quote:




Danscraftbeer said:


> I can never get an accurate pre boil gravity. Said it many times before. If I do 5 tests I get 5 different readings at any time through to 30 minutes boiled. still cant get a consistent reading


Do you mean that you leave the hydrometer in the same sample, or repeatedly test the same sample, and the reading keeps changing? If so, that's very odd.


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## Rocker1986 (28/9/16)

Sugars don't move around in solution like that under normal conditions. If they did then bottles of cordial wouldn't stay at the same even concentration for their lifetimes. Beers would exhibit varying levels of residual sweetness and body and colour depending on what part of the batch you are drinking, or all the residual sugar would settle in the bottom after a while, which doesn't happen. Once they are dissolved and in suspension they stay there unless you reach saturation point.

Something is ******* up your readings, but it isn't that.


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## Danscraftbeer (28/9/16)

Rocker1986 said:


> Do you mean that you leave the hydrometer in the same sample, or repeatedly test the same sample, and the reading keeps changing? If so, that's very odd.


No

I batch sparge and pre boil each batch. Then when my keggle is full I try to take a pre boil reading. I take more than just one reading. Maybe that is something in itself. I geek out on brewing. I have to confirm it. So when my pre boil reading suggests I've got 110% efficiency then that cant be right. So mix well while boiling and re test, and re , and re, and re test!!!!
Sorry but I fail at getting a consistent pre boil gravity reading via Refractometer and Hydrometer readings on a pre boil. Cooling the sample and all etc's.
I advocate all that labour as a waist of time considering the total efficiency is the all important thing and that is confirmed.
Darks ~ 73%
Mids, IPA's ~ 76%
5%ABV Pales get 76% up to 82% for a low carb all grain. :beerbang:


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## Lyrebird_Cycles (28/9/16)

mtb said:


> Well, the OG is 1.049.


At what volume?


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## mtb (28/9/16)

Lyrebird_Cycles said:


> At what volume?


60L.. so BH efficiency ended up being ~82%. Not bad at all but I had planned for 46L. The boil was fairly vigorous.


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## mtb (28/9/16)

I filled two 25L fermenters and took the remaining 10L to boil down and add back into the fermenters. That oughta balance the IBU:OG


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## Lyrebird_Cycles (28/9/16)

I don't see that would work: I can't see a mechanism by which the sugar concentrates but the iso alpha acids don't.

I guess you could boil it for long enough to degrade the IAAs but that's a long time.


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## Danscraftbeer (28/9/16)

So you've got something around 60 IBU, Pale, low carb. I'd go that. Before software one of my best pre all grain beers was with Sarochi Ace hops. After I got software I punched in that old brew and it turned out around 55IBU. I have to try it again all grain.


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## mtb (28/9/16)

Lyrebird_Cycles said:


> I don't see that would work: I can't see a mechanism by which the sugar concentrates but the iso alpha acids don't.
> 
> I guess you could boil it for long enough to degrade the IAAs but that's a long time.


My understanding of bittering hops (and their AAs) is that their bittering value plateaus after around 90min. So if I boil this 10L for a good few hours I'll increase its OG without increasing its IBUs at the same rate.


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## MHB (29/9/16)

Actually in an open boil that is probably closer to 400 minutes, but it is going to depend on a lot of variables one of them being that if there are still any hops or un-isomerised Alpha aids in the wort you will still be making Iso-Alpha, as well as breaking down some of the Iso.
Even if you boiled for 2 hours and halved the volume and doubling the SG, you would still be concentrating the existing Iso-Alpha at pretty much the same rate (i.e. doubling it).

I cant understand how getting an accurate SG reading is so hard, I mean it isn't rocket science, probably easier than reverse parking a car!
Whether its in the kettle pre or post boil, or in the fermenter, make sure you stir thoroughly, run some off (more than the volume in the tap/any plumbing - other than in the fermenter just return the pre-run to the top) take your sample, adjust the temperature to close to 20oC (Measured Accurately), take your reading.

Just make sure your thermometer and hydrometer are accurate and develop a process that works and do it the same way every time, we are talking really basic brewing skills, something I would expect a kit brewer to be able to do accurately and consistently.
Mark


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## Barge (29/9/16)




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## mtb (29/9/16)

MHB said:


> I cant understand how getting an accurate SG reading is so hard, I mean it isn't rocket science, probably easier than reverse parking a car!
> Whether its in the kettle pre or post boil, or in the fermenter, make sure you stir thoroughly, run some off (more than the volume in the tap/any plumbing - other than in the fermenter just return the pre-run to the top) take your sample, adjust the temperature to close to 20oC (Measured Accurately), take your reading.
> 
> Just make sure your thermometer and hydrometer are accurate and develop a process that works and do it the same way every time, we are talking really basic brewing skills, something I would expect a kit brewer to be able to do accurately and consistently.
> Mark


Have you seen some people try reverse parking a car..? 
I'm doing this the same way I always have. Took my sample direct from the wort after giving it a good stir. Adjusted for temp via this handy calculator . I have to assume that my hydrometer is faulty - even though it reads 1.00 in tap water, it may mis-report a reading at higher gravities anyway.


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## Lyrebird_Cycles (29/9/16)

mtb said:


> My understanding of bittering hops (and their AAs) is that their bittering value plateaus after around 90min. So if I boil this 10L for a good few hours I'll increase its OG without increasing its IBUs at the same rate.





MHB said:


> Actually in an open boil that is probably closer to 400 minutes, but it is going to depend on a lot of variables one of them being that if there are still any hops or un-isomerised Alpha aids in the wort you will still be making Iso-Alpha, as well as breaking down some of the Iso.


In normal conditions the peak utilisation occurs at around 4 hours. I wrote a calculator that allows you to work this out: aussiehomebrewer.com/topic/91684-improving-precision-in-ibu-calculations


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## klangers (29/9/16)

I'd say that your issue is your adjustment for temperature.


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## mtb (29/9/16)

klangers said:


> I'd say that your issue is your adjustment for temperature.


Must've been. Next time I will be cooling my sample rather than adjusting with a calculator.
All in all though, final BH efficiency was 82%, so I got the increase I was looking for (I was around 62% before deciding to batch sparge).


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## bradsbrew (29/9/16)

That is where a refractometer is handy.


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## mtb (29/9/16)

bradsbrew said:


> That is where a refractometer is handy.


Yep, buying one next week.


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## Lyrebird_Cycles (29/9/16)

klangers said:


> I'd say that your issue is your adjustment for temperature.


I thought that too so I checked it and it's near enough.

I'm guessing MTB used the Brewer's friend calculator; it takes into account the variation in CTE with temperature rather than assuming a constant value of 200 PPM / oC.


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## klangers (29/9/16)

Mmm, it is possible for the hydrometer, if cold, to reduce the temperature of the wort upon sampling, making the temperature to which one adjusts no longer relevant. That's the difficulty I've encountered personally anyhow.


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## Lyrebird_Cycles (29/9/16)

Unlikely: weird factoid, the volumetric heat capacities of most solids are within 20% of a value of 3 MJ/m3, water is anomalously high at almost 4.2, glass is a bit low at 2.1. Combined with density, this means the specific heat capacity of glass is about one fifth that of water.

The mass of the hydrometer is by definition equal to the volume of fluid displaced, in a normal scenario with adequate clearance between hydrometer and bulb the hydrometer represents about one quarter of the combined mass of the system. Accordingly, a 40 degree difference in temperature between glass and sample would equilibrate out to a temperature drop of about 2.5 degrees.

Before anybody asks: the linear CTE of borosilicate glass is about 3 ppm and more or less linear with temperature so the resultant expansion of the hydrometer is not material.


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## klangers (29/9/16)

Yes I am aware of that, but you forget the lead mass at the bottom of the bulb. 

Unlikely, but has happened to me before - possibly a combination of multiple errors - error in temperature, error in calculator, some temperature loss upon sampling, temperature loss as the hydrometer equalises and slowly disspates heat.

Possible to all add up to the error experience by the OP.


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## n87 (29/9/16)

Lyrebird_Cycles said:


> Before anybody asks: the linear CTE of borosilicate glass is about 3 ppm and more or less linear with temperature so the resultant expansion of the hydrometer is not material.


Lucky you mention that... otherwise i may have pulled you up on it :unsure:


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## mtb (29/9/16)

Lyrebird_Cycles said:


> I'm guessing MTB used the Brewer's friend calculator; it takes into account the variation in CTE with temperature rather than assuming a constant value of 200 PPM / oC.


Correct, I used Brewer's Friend.




klangers said:


> Mmm, it is possible for the hydrometer, if cold, to reduce the temperature of the wort upon sampling


I took wort temp from the hydrometer tube itself via an STC-1000 probe




Lyrebird_Cycles said:


> Unlikely: weird factoid, the volumetric heat capacities of most solids are within 20% of a value of 3 MJ/m3, water is anomalously high at almost 4.2, glass is a bit low at 2.1. Combined with density, this means the specific heat capacity of glass is about one fifth that of water.
> 
> The mass of the hydrometer is by definition equal to the volume of fluid displaced, in a normal scneario with adequate clearance between hydrometer and bulb the hydrometer reresents about one quarter of the combined mass of the system. Accordingly, a 40 degree difference in temperature between glass and sample would equilibrate out to a temperature drop of about 2.5 degrees.
> 
> Before anybody asks: the linear CTE of borosilicate glass is about 3 ppm and more or less linear with temperature so the resultant expansion of the hydrometer is not material.


Great bit of knowledge there mate - I'm always sure to watch out for your posts..


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## Lyrebird_Cycles (29/9/16)

klangers said:


> Yes I am aware of that, but you forget the lead mass at the bottom of the bulb.


The specific heat capacities of lead and bismuth are around 1/40th the value for water so including them in the calculation reduces the error. If the intention is to show that the error is small it is usual to go with the largest possible error (worst case scenario).

That's why I mentioned the volumetric heat capacities all being in a narrow range: this means the specific heat capacities of dense materials tend to be very low.


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## Rocker1986 (29/9/16)

I just stick my pre-boil sample in the fridge as soon as I take it, it's down to around 20C in a couple of hours or less depending on what temp it started at. I have borosilicate glass testing jars which makes it easier I suppose.

The post boil sample I take into a 500mL pyrex jug after transferring the wort to the cube and just leave to sit on the bench for a few hours to cool down before taking a reading. It's usually full of hot break so this allows that to settle and get a clear wort sample too.


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## klangers (29/9/16)

Lyrebird_Cycles said:


> The specific heat capacities of lead and bismuth are around 1/40th the value for water so including them in the calculation reduces the error. If the intention is to show that the error is small it is usual to go with the largest possible error (worst case scenario).
> 
> That's why I mentioned the volumetric heat capacities all being in a narrow range: this means the specific heat capacities of dense materials tend to be very low.


I agree with you on that. I was more trying to be a smart arse splitting hairs with your very thorough post. 

I think we both know there's more to it than specific heat capacity differences. There's definitely more to it than simply the thermal mass of the submerged hydrometer. How the wort gets poured into the hydrometer and sample jar means that it can mix with the air, contacts the side of the jar which the brewer might be holding etc etc. 

We can be going to and fro about the details, but at the end of the day if all other inputs check out,the most obvious thing to me is that the temperature that was plugged into the calculator was wrong or at least not representative of reality at that point in time.


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## dr K (1/10/16)

My first thought was that the kilo bags weighed somewhat more than a kilo. Looks like you should be buying more milled bags from that shop !!!
Your pre boil volume was estimated I know but if your wort was 3cm below the top of a 70litre pot thats hardly enough wiggle room for expansion let alone rapid boiling.....
but you had a rapid boil and still ended up with 60 litres?
What obvious point am I missing.??

K


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## mtb (4/10/16)

Just finished sparging a new batch. Same high pre-boil reading as the last brew - 1.066 whereas the recipe calls for 1.056 with 80% BH efficiency - So I dug out another hydrometer I had lying around and took a reading from the same sample of wort, cooled to room temp, in two separate hydrometers.

Same reading on both.

I'm going to push ahead and see how it ends up.. strange that two hydrometers are a) incorrect/faulty and b} have the same margin of error. Yes, they're calibrated to 20C.


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## SBOB (4/10/16)

is it possible your measurements elsewhere are off.. i.e. volumes?


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## mtb (4/10/16)

Thought that, but I measured. 2L under predicted volume


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## Lyrebird_Cycles (5/10/16)

Any chance the hydrometer doen't have enough clearance in the tube? Ideally you want the ID of the tube to be twice the OD of the hydrometer or more.

An easy test for this is tow take two readings, one by letting the hydrometer settle and then gently lifting it a cm or so and letting it resettle, the other by pushing it down by a cm or so and letting it resettle. Ideally you'll get the same reading both times.


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## mtb (5/10/16)

Gave that a go (I saved a pre-boil gravity sample in case). Same reading.

It looks like I hit my targets after all - 83% BH efficiency, it seems that I'm just three points under target OG but a couple litres over target volume. I'd say Beersmith was just giving me funky target pre-boil gravity targets, I'll tune it to accommodate


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## contrarian (5/10/16)

Just had a look at you beersmith file and your boil size is bigger than your kettle with you batch size only being a few litres short of your pot size. 

So you say your pot is 50L but your boil size is 15.13G which is 57.273L and your batch size is 12.13G or about 46L. 

I'm guessing this has something to do with your sparge and when you are adding this in but I think if you sort this out the gravity readings you are getting will make more sense.


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## mtb (5/10/16)

contrarian said:


> Just had a look at you beersmith file and your boil size is bigger than your kettle with you batch size only being a few litres short of your pot size.
> 
> So you say your pot is 50L but your boil size is 15.13G which is 57.273L and your batch size is 12.13G or about 46L.
> 
> I'm guessing this has something to do with your sparge and when you are adding this in but I think if you sort this out the gravity readings you are getting will make more sense.


My pot is 70L - must've left the equipment profile at the 50L setting. Possibly a contributor to my issues but I wouldn't expect there to be a huge difference in equipment stats (ie boil off rate) between a 50L and 70L pot


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## Rocker1986 (5/10/16)

mtb said:


> Well, the OG is 1.049. No clue what prompted the hydrometer to read so high pre-boil... I shit you all not, it read 1.048 pre-boil, with adjustment for temperature, that was 1.061.


This taken from the first page. Something is wrong with your pre-boil readings. You can't end up with a lower SG after the boil. Buggered if I know what it is though.


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## contrarian (5/10/16)

That makes more sense but I still think it is difficult to pull 46L out of a 70L pot. I have the same set up and normally manage about 40L into cubes with about 5-7L of boil off over 60min and about 5L of trub loss. 

I have managed 3 15L cubes of 1.045 pale ale but that was really pushing the system to its limits. 

So is the 46L your post boil volume or are you getting into your fermenter?


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## mtb (5/10/16)

I hit 50L into the fermenter. I wouldn't be able to achieve that if I BIAB'd with the full volume as mash water - simply not enough space in the pot - so instead I have 40L water for my mash, and then sparge with the other 24L to hit 66L pre-boil volume. This kills two birds with one stone as I can sparge and get the high BH efficiencies I'm after, while also topping up the pot after removing the grain bag and clawing back headspace.


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## contrarian (5/10/16)

Are you topping up with water or with sparged wort? 

It might be worth checking the gravity of the running a from the sparge to see what that is contributing as adding volume of lower gravity wort to the boil could be diluting it along the way which could explain a drop in gravity.


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## mtb (5/10/16)

Topping up with sparged wort.
I only sparged with as much water as was required to achieve the pre-boil volume as per the recipe. I suspect that the grain didn't retain as much water as Beersmith expected, which would've caused it to dilute the wort and cause my slight OG undershoot & excess volume


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## contrarian (5/10/16)

Next time you brew measure the gravity of your sparged wort as it will make a difference that can be calculated. 

It will also make it a bit more difficult to measure your evaporation, not impossible, just more challenging. 

If you keep your process the same over a few brews then you will get the hang of it fairly quickly.


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## mtb (5/10/16)

Sounds good, thanks for the input. I just started sparging so will put a few batches down and see how I go.

Gotta love that BH efficiency though, 83%!


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## contrarian (5/10/16)

I'm not that driven by efficiency. As long as I am relative consistent for similar gravity brews it means I can replicate things reasonably well given the variable in the home brew environment!

Brewhouse efficiency also is impacted by losses to grain absorption and trub. I don't have a pick up tube so always lose a few litres there which drops it by a few points!

In probably far too casual in my approach to brewing (with the exception of cleaning) but that's the way I like it and I'm happy with my beer!


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## mtb (5/10/16)

Consistency is definitely preferable - my issue now lies in consistency - but it's nice to be able to get an extra 15% efficiency with very little effort. My sparging solution is very ghetto; I just drilled a bunch of holes in the bottom of a fermenter, cut the top off, put the grain bag in there after mashout, and dump the sparge water on top from a $40 hot water urn I found on Gumtree. It sits on a wire basket atop my BIAB pot so the runnings dump straight in.


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## huez (5/10/16)

Get yourself a long steel ruler and use it to calibrate the volume of your pot, fill it up one litre at a time and mark the ruler or take note of many mm one litre is. I doubt your pot is exactly 70 litres. Your volumes seem to be all over the place. I'd be looking at some of your settings in beersmith as well, grain absorption, pot sizes, dead spaces, boil off rates etc. Change one at a time and take notes. Doesn't really explain your initial high reading though, somethings whack, keep brewing until you get it right! 

What kind of voodoo are you using to stop a boil over with an almost full pot?


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## mstrelan (5/10/16)

huez said:


> Get yourself a long steel ruler and use it to calibrate the volume of your pot, fill it up one litre at a time and mark the ruler or take note of many mm one litre is. I doubt your pot is exactly 70 litres. Your volumes seem to be all over the place. I'd be looking at some of your settings in beersmith as well, grain absorption, pot sizes, dead spaces, boil off rates etc. Change one at a time and take notes. Doesn't really explain your initial high reading though, somethings whack, keep brewing until you get it right!


+1 for this. If you have the same pot as me from Craft Brewer I measured it out to be approx. 6.4mm per litre, by filling it 2L at a time using a jug and a set of scales. From memory, the pot dimensions are 450mm diameter x 450mm depth. Using maths that equates to 71.569L.


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## mtb (5/10/16)

Sounds like I'd better get to work verifying the volume of my pot.

No such voodoo here, I've never had to actually stop a boilover, I've never had one start to occur. When I do my boil I run the 2400W element and gas burner on low, then slowly ramp it up til I'm getting bubbles breaking the surface, and I leave it there. Maybe I'm not boiling hard enough h34r:


My pot is actually 71L according to the invoice from CheekyPeak. That'll learn me to approximate. The metal ruler idea is good though.. I could etch volume markings into it with my Dremel. Entirely unnecessary but I just can't stop myself using that thing


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## mstrelan (5/10/16)

I've attached my measurements for the Craft Brewer pot. I gave up after 50L.

You can also use vinegar and a battery to etch volume markings. 

View attachment kettle.xlsx


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## mtb (5/10/16)

Super keen to etch the markings, just have to find an adhesive number stencil that doesn't cost something ludicrous


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## Mozz (5/10/16)

Whats the pot dimensions? 
Internal diameter and height?
Just calculate the volume of the pot based on its dimensions. 
Not hard from there to work out the measurements for the volume markings as well.
Post it and I'll calculate if you like.
Most accurate way.


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## mtb (5/10/16)

Not hard to calculate if the pot were empty.. but I have a heating element installed which would offset that.
Yes, I could also calculate the volume occupied by the element and subtract that, but I need to get volume etchings made anyway, so it's a 2 birds 1 stone situation


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## mtb (5/10/16)

(also the pot has a curved bottom - it'd be a very slight difference, but a difference nonetheless)


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## Mozz (6/10/16)

Just trying to help.
Cheers


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## mtb (6/10/16)

And it's much appreciated mate


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## Lyrebird_Cycles (6/10/16)

Mozz said:


> Just calculate the volume of the pot based on its dimensions.
> Not hard from there to work out the measurements for the volume markings as well.
> Post it and I'll calculate if you like.
> Most accurate way.


It often isn't.

In industry tanks come with gauging spreadsheets prepared by the manufacturer. We then regauge the tanks using a magnetic flowmeter and dip tape, surprising how large the errors can be: usually caused by sections of the tank being ellipsoidal rather than circular.


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