I brewed a chocolate stout yesterday using the calculator as a guide. Everything seemed to go well apart from i ended up with 17 litres of wort in the fermenter instead of the 16 litres i was expecting. My OG was also down 8 points from the target.
Do you think the drop in gravity is down to topping up the kettle too much during the boil or just poor efficiency rates?
The Actuals tab of the calc, once i had inputted my figures, gave the following efficiencies:
Actual Mashout Efficiency: 78.9%
Actual Start of Boil Efficiency: 77%
Actual End of Boil Efficiency: 97.5%
Into Fermenter Efficiency: 69.4%
Cheers for any advice.
Dave
EDIT: Sorry, after looking back at the calc i am only a litre or so over target so i am guessing this wouldn't equate to a drop of 8 points of gravity. Therefore i should change the name of the topic. Is that acceptable?
Post #2 made 13 years ago
That's great you took a bit of time to collect some figures along the way Brad 
,
Topping up the kettle during the boil will not really affect your evaporation loss* so I wouldn't be looking at that unless you dumped large amounts in at a time which resulted in the wort coming off the boil for long periods of time. Even this though would not explain your 'suspected' discrepancy so ignore this side of things completely.
The End of Boil Efficiency reading falls out of line with the others so you can assume that you have either a dodgy volume or gravity reading at that point of the brew. (Something is definitely way out there). It's pretty normal to get one dodgy reading so never take one reading at one part of the brew as 'gospel'.
Basically, I don't think there is anything to worry about here. I reckon you just have a dodgy reading. If you can post your 'The Calculator' file up and the actual volume and gravity readings I reckon we could probably narrow down where the measurement error occurred. Remember they happen all the time and we all make them no matter how careful we are** - it's a mystery of brewing
.
PP
* The formula in The Calculator used to estimate evaporation works off kettle diameter. It was a formula derived from collecting figures from a number of brewers with different size kettles. It is less accurate for very narrow or very wide kettles however something was needed to get people in the ball park. Your ending up with 17 L instead of 16 L is very close though and you'll find evaporation varies from day to day and therefore from brew to brew.
For example, let's say you had two kettles side by side on the same day and one had 40 L at the boil start and the other had 80 L. If the first kettle ended up with 30 L at the end of the boil, you would expect the other to end up with 70L. In other words, both would lose 10L.)
** I think there could be a combination of two things here. At the end of the day though, I'd be fairly confident in your brew. I think you may have closer to your OG than you suspect.
,Topping up the kettle during the boil will not really affect your evaporation loss* so I wouldn't be looking at that unless you dumped large amounts in at a time which resulted in the wort coming off the boil for long periods of time. Even this though would not explain your 'suspected' discrepancy so ignore this side of things completely.
The End of Boil Efficiency reading falls out of line with the others so you can assume that you have either a dodgy volume or gravity reading at that point of the brew. (Something is definitely way out there). It's pretty normal to get one dodgy reading so never take one reading at one part of the brew as 'gospel'.
Basically, I don't think there is anything to worry about here. I reckon you just have a dodgy reading. If you can post your 'The Calculator' file up and the actual volume and gravity readings I reckon we could probably narrow down where the measurement error occurred. Remember they happen all the time and we all make them no matter how careful we are** - it's a mystery of brewing
. PP
* The formula in The Calculator used to estimate evaporation works off kettle diameter. It was a formula derived from collecting figures from a number of brewers with different size kettles. It is less accurate for very narrow or very wide kettles however something was needed to get people in the ball park. Your ending up with 17 L instead of 16 L is very close though and you'll find evaporation varies from day to day and therefore from brew to brew.
For example, let's say you had two kettles side by side on the same day and one had 40 L at the boil start and the other had 80 L. If the first kettle ended up with 30 L at the end of the boil, you would expect the other to end up with 70L. In other words, both would lose 10L.)
** I think there could be a combination of two things here. At the end of the day though, I'd be fairly confident in your brew. I think you may have closer to your OG than you suspect.
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Post #3 made 13 years ago
Here's the file, cheers.
The actual readings i took were:
OG at Mash Out: 1030
OG Post Boil (cooled to 20C): 1038
Cheers
The actual readings i took were:
OG at Mash Out: 1030
OG Post Boil (cooled to 20C): 1038
Cheers
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Post #4 made 13 years ago
Good Day, I hope this is Not too far Off Topic, but, Please look over the four posts at http://www.biabrewer.info/viewtopic.php?f=5&t=1681 getting the Correct Final Volume.
Boil off volumes at a "set time" vary mostly due ambient Humidity and Altitude/Barometric pressure.
So I have to "measure" the Boil volume near the "end of boil" time to insure the Final Volume is "close" and adjust the final Hop additions as needed.
The one liter/quart overage with a 12 quart/liter batch is an 1.08333% volume increase so the S.G into the fermenter would be 8% lower.
I had a similar problem for my first 20 batches.
Boil off volumes at a "set time" vary mostly due ambient Humidity and Altitude/Barometric pressure.
So I have to "measure" the Boil volume near the "end of boil" time to insure the Final Volume is "close" and adjust the final Hop additions as needed.
The one liter/quart overage with a 12 quart/liter batch is an 1.08333% volume increase so the S.G into the fermenter would be 8% lower.
I had a similar problem for my first 20 batches.
Last edited by joshua on 08 Oct 2012, 21:45, edited 1 time in total.
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Post #6 made 13 years ago
Okay, this is a different scenario than I thought 
...
We have a maxi-BIAB here and this is a totally different scenario from a full-volume (pure) BIAB. I think we can find the reason for your problem a bit quicker. The thread title should probably be "Gravity too low on my Maxi-BIAB" rather than "Too much wort". I should have mentioned above that getting 17 L from an estimate of 16 L is perfectly fine. In other words, no problems with volumes 
.
There's two real problems going on here. The first I can't help you with and that concerns the efficiency numbers given in the Maxi_BIAB calculator you have used and where and how you have in-putted your figures. There are so many different measurements in the Maxi-BIAB Calculator it always takes me hours to work out where each calculation is sourced but, the real problem for you I'm pretty sure is as follows...
At the end of the day, your volume was about right but your gravity was far too low. To investigate this fully, I'd need to know how much water you added and at what stages you added it. But, even without doing this, I can see there that basically a mash efficiency problem has gone on here. This will almost definitely be due to not enough water being exposed to the actual grain.
The goal of Maxi-BIAB is to compensate as much as possible for having too small a kettle for the batch size you are asking. From what I am seeing from the .xls version here though, you probably could have done a full-volume BIAB (14L into packaging from a 34 L pot I am reading?). You should always full-volume when you can. In other words, get as much water in contact with the grain as soon as you possibly can. The more you move away from this rule (i.e. the later you add water to the grain or, worse still, do straight dilutions, the more your efficiency will suffer.).
I think the first thing for now would be to have a look at this post and see if it rings any bells?
PP
...We have a maxi-BIAB here and this is a totally different scenario from a full-volume (pure) BIAB. I think we can find the reason for your problem a bit quicker
. The thread title should probably be "Gravity too low on my Maxi-BIAB" rather than "Too much wort". I should have mentioned above that getting 17 L from an estimate of 16 L is perfectly fine. In other words, no problems with volumes .There's two real problems going on here. The first I can't help you with and that concerns the efficiency numbers given in the Maxi_BIAB calculator you have used and where and how you have in-putted your figures. There are so many different measurements in the Maxi-BIAB Calculator it always takes me hours to work out where each calculation is sourced but, the real problem for you I'm pretty sure is as follows...
At the end of the day, your volume was about right but your gravity was far too low. To investigate this fully, I'd need to know how much water you added and at what stages you added it. But, even without doing this, I can see there that basically a mash efficiency problem has gone on here. This will almost definitely be due to not enough water being exposed to the actual grain.
The goal of Maxi-BIAB is to compensate as much as possible for having too small a kettle for the batch size you are asking. From what I am seeing from the .xls version here though, you probably could have done a full-volume BIAB (14L into packaging from a 34 L pot I am reading?). You should always full-volume when you can. In other words, get as much water in contact with the grain as soon as you possibly can. The more you move away from this rule (i.e. the later you add water to the grain or, worse still, do straight dilutions, the more your efficiency will suffer.).
I think the first thing for now would be to have a look at this post and see if it rings any bells?
PP
Last edited by PistolPatch on 08 Oct 2012, 21:47, edited 2 times in total.
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Post #7 made 13 years ago
Hmm. I thought i did a standard BIAB?
I warmed up 26L of water to strike temp and added my entire grain bill. I had to remove the bag twice during the 90minute MASH so i could warm the water back up to temp. Any water drained from the bag was placed back into the kettle.
After mash out i let the bag drain/gave it a squeeze whilst i got the kettle up to boil. I then added what had drained ( i didnt measure the volume) back to the boil.
I assumed that so far i had done a standard BIAB. Have i got this wrong?
During the 90min boil i topped up with approx 3litres of boiling water (is this where i moved into maxi-BIAB territory?)
Apologies if i am not seeing the wood for the trees here!
I warmed up 26L of water to strike temp and added my entire grain bill. I had to remove the bag twice during the 90minute MASH so i could warm the water back up to temp. Any water drained from the bag was placed back into the kettle.
After mash out i let the bag drain/gave it a squeeze whilst i got the kettle up to boil. I then added what had drained ( i didnt measure the volume) back to the boil.
I assumed that so far i had done a standard BIAB. Have i got this wrong?
During the 90min boil i topped up with approx 3litres of boiling water (is this where i moved into maxi-BIAB territory?)
Apologies if i am not seeing the wood for the trees here!
Last edited by bradfordlad on 08 Oct 2012, 23:28, edited 1 time in total.
Post #8 made 13 years ago
BradfordLad, Just adding more water to Top up, is not MAXI-BIAB, just adding time to boil off, or more "End of Boil Volume" which is a normal thing depending on Volume left in the grains.
Maxi-BIAB is if you drained the bag and then Rinsed/Dunked/Teabaged the grains in another Pot/Kettle of water, and used that water to top up the kettle. Which will add some Gravity to the Wort!
Maxi-BIAB is if you drained the bag and then Rinsed/Dunked/Teabaged the grains in another Pot/Kettle of water, and used that water to top up the kettle. Which will add some Gravity to the Wort!
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Post #9 made 13 years ago
Hi
I'm looking at your problem and I see from your Calc sheet that the total water required is 25.99 L you state that you warmed up 26L and doughed in. So you started with the correct volume. Where did the other 3 litres added during the boil come from ? How big is the volume of your kettle ?
Yeasty
I'm looking at your problem and I see from your Calc sheet that the total water required is 25.99 L you state that you warmed up 26L and doughed in. So you started with the correct volume. Where did the other 3 litres added during the boil come from ? How big is the volume of your kettle ?
Yeasty
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Post #10 made 13 years ago
hi there.
My kettle is 33litres.
I think i know where i have gone wrong. Maybe.
B66 of the actuals tab. I *think* i forgot to put 1030 in when i should have done. I think i put this in later due to waiting for the sample to cool down. The default figure in the cell is 1062! Due to this i was expecting to have 6cm of headspace at the end of boil. I have added water to the boil to top up to this figure of 6cm. I should have ended up with 15.7cm of headspace ie i should have let the wort evaporate rather than keep adding. Schoolboy error.
Does this sound plausible?
My kettle is 33litres.
I think i know where i have gone wrong. Maybe.
B66 of the actuals tab. I *think* i forgot to put 1030 in when i should have done. I think i put this in later due to waiting for the sample to cool down. The default figure in the cell is 1062! Due to this i was expecting to have 6cm of headspace at the end of boil. I have added water to the boil to top up to this figure of 6cm. I should have ended up with 15.7cm of headspace ie i should have let the wort evaporate rather than keep adding. Schoolboy error.
Does this sound plausible?
Post #11 made 13 years ago
Hi Bradford LAd
I can't say for certain if that is where you made a mistake, but what I do know is that the version of the calculator you are using is probably the wrong version for your needs and you have over complicated things. I use it but only because it has a conversion tool for swapping to US gallons, which comes in handy when helping our US friends across the pond.
As you don't maxi biab you can forget all the backend maxi stuff on that sheet and just go off the Volumes/Grain Bill/Hop Bill and efficiency tabs. You may be better off using the calculator found Here
I've just quickly checked out your previous posts and it looks like we have assumed that you were Maxi-Biabing (sorry
), I therefore wouldn't worry to much about the last brew and would put it down to experience. You have just said that your kettle is 33L, so the absolute max you can biab normally is around 18.7L into fermenter or 20.88 end of boil volume at 20c. Giving you about 17L of finished beer. Even then you will want to hold a couple of litres back to prevent spillage when douging in and pulling your bag**. I'd suggest brewing a couple of brews at this length until you have things off pat then you can start to ramp things up.
** 18.8 into fermenter equals a mash volume of about 33L which is your kettle max. Holding back 4L until after mash out will give you 4cm of breathing space for when you pull the bag and prevent spillages. Your start of boil volume(after adding the 4L) will be around 29.5L giving you 4cm of head room. (watch out for boil overs !!!!)
Hope this helps, any further questions just
don't hold back..
Yeasty
I can't say for certain if that is where you made a mistake, but what I do know is that the version of the calculator you are using is probably the wrong version for your needs and you have over complicated things. I use it but only because it has a conversion tool for swapping to US gallons, which comes in handy when helping our US friends across the pond.
As you don't maxi biab you can forget all the backend maxi stuff on that sheet and just go off the Volumes/Grain Bill/Hop Bill and efficiency tabs. You may be better off using the calculator found Here
I've just quickly checked out your previous posts and it looks like we have assumed that you were Maxi-Biabing (sorry
), I therefore wouldn't worry to much about the last brew and would put it down to experience. You have just said that your kettle is 33L, so the absolute max you can biab normally is around 18.7L into fermenter or 20.88 end of boil volume at 20c. Giving you about 17L of finished beer. Even then you will want to hold a couple of litres back to prevent spillage when douging in and pulling your bag**. I'd suggest brewing a couple of brews at this length until you have things off pat then you can start to ramp things up. ** 18.8 into fermenter equals a mash volume of about 33L which is your kettle max. Holding back 4L until after mash out will give you 4cm of breathing space for when you pull the bag and prevent spillages. Your start of boil volume(after adding the 4L) will be around 29.5L giving you 4cm of head room. (watch out for boil overs !!!!)
Hope this helps, any further questions just
don't hold back..Yeasty
Last edited by Yeasty on 09 Oct 2012, 00:24, edited 2 times in total.
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Post #12 made 13 years ago
Cheers for that Yeasty. I am 95% sure thats where i went wrong.
I was planning a maxi-biab for my next brew but i may well scale it down from 23L to 17L as you say and see how it goes. And try not to flap around so much on the actual brew day
I was planning a maxi-biab for my next brew but i may well scale it down from 23L to 17L as you say and see how it goes. And try not to flap around so much on the actual brew day
Post #13 made 13 years ago
bradfordlad wrote:Cheers for that Yeasty. I am 95% sure thats where i went wrong.
I was planning a maxi-biab for my next brew but i may well scale it down from 23L to 17L as you say and see how it goes. And try not to flap around so much on the actual brew day
that really is a good move, get your methods down pat before taking the next step. Believe me once you've got a couple of more brews under your belt it will become second nature and you'll look back wondering what all the fuss was about. 
Yeasty
Last edited by Yeasty on 09 Oct 2012, 03:22, edited 2 times in total.
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Post #14 made 13 years ago
Hello again Yeasty, and everyone else
Would this work in theory, particularly the sparge aspect, or am i asking you to answer an impossible question?
Brew Length: 17L
OG: 1064
Grain Bill: 5.124Kg
90 minute mash/90 minute boil
mash in 27L (leaving about 24L of actual wort)
sparge in 4L
Start of Boil Vol: 28L
End of Boil Vol: 21L
Cheers.
Would this work in theory, particularly the sparge aspect, or am i asking you to answer an impossible question?
Brew Length: 17L
OG: 1064
Grain Bill: 5.124Kg
90 minute mash/90 minute boil
mash in 27L (leaving about 24L of actual wort)
sparge in 4L
Start of Boil Vol: 28L
End of Boil Vol: 21L
Cheers.
Post #15 made 13 years ago
Good Day BradfordLad, It looks pretty good, I would mash at 23L and sparge with 8L since your using 5.125Kg grain, as this would give a good rinse to that amount of grains. Just My $0.02us
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Post #16 made 13 years ago
Cheers Joshua. Could i ask, have you used a certain ratio to come up with that figure?
Post #17 made 13 years ago
BradfordLad, I have found a sparge of 2.5Kg per 4L make a good "Soup" for a "dunk/teabag" sparge and allows the gravity to drop alot in the spent grains.
For US folks 5 pounds/gallon is a good ratio.
For US folks 5 pounds/gallon is a good ratio.
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Post #18 made 13 years ago
Dave,
I really think you should do a pure BIAB (no sparging or dilutions) on your next brew with a recipe that has an OG of about 1.050. Also use the main 'The Calculator' on the site for that brew. This way you'll be starting from a known base and can check that you have all the basics correct.
Doing this will also give you the time to take three distinct sets of gravity and volume readings - pre-boil, end of boil and into fermentor. These six distinct measurements (3 vol and 3 gravity) will be necessary for you to take to find if there is a problem going on. Lack of measurements often makes it impossible to find a problem as has turned out to be the case here.
So, keep the next one simple I reckon,
PP
I really think you should do a pure BIAB (no sparging or dilutions) on your next brew with a recipe that has an OG of about 1.050. Also use the main 'The Calculator' on the site for that brew. This way you'll be starting from a known base and can check that you have all the basics correct.
Doing this will also give you the time to take three distinct sets of gravity and volume readings - pre-boil, end of boil and into fermentor. These six distinct measurements (3 vol and 3 gravity) will be necessary for you to take to find if there is a problem going on. Lack of measurements often makes it impossible to find a problem as has turned out to be the case here.
So, keep the next one simple I reckon
,PP
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Post #19 made 13 years ago
Joshua - Cheers for the info
PP - I know you're right......it's just in my nature to run like Usain Bolt before i can toddle, never mind walk!
I do take your advice very seriously though and will probably rein my eagerness in
cheers!
PP - I know you're right......it's just in my nature to run like Usain Bolt before i can toddle, never mind walk!
I do take your advice very seriously though and will probably rein my eagerness in
cheers!
Post #20 made 13 years ago
Yes, eagerness can be a double-edged sword. I have a room full of useless brewing equipment here to prove that 
. (It was fun though.)
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Post #21 made 13 years ago
Just spotted something PP
On my last brew i assumed that "Into fermenter" gravity would be the same as "end of boil" gravity.
Is this an incorrect assumption to make?
On my last brew i assumed that "Into fermenter" gravity would be the same as "end of boil" gravity.
Is this an incorrect assumption to make?
Post #22 made 13 years ago
If you adjust the Gravity for the temperature of the "end of boil" it will, OR let it cool to Pitching Temperature then it will be "Into fermenter"
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Post #23 made 13 years ago
Into fermenter and end of boil gravity can be considered the same, provided you haven't done anything like a post boil dilution or a top up of your fermenter.bradfordlad wrote:Just spotted something PP
On my last brew i assumed that "Into fermenter" gravity would be the same as "end of boil" gravity.
Is this an incorrect assumption to make?
I personally take my E.O.B.G reading when I'm filling my fermenter or cube as it's the easiest way.
I think this is a common trait with new brewers, you read a lot of beer and brewing related stuff and a simple 4% Bitter recipe sounds boring and uninteresting, you want to brew that beer with the WOW factor. We've all done it so I can't knock you for wanting to go big but looking at your proposed recipe and apart from it involving sparging and topping up, its a strong brew that will come out at around 6.5/7% ABV. The conditioning times for these stronger brews are longer than say for a simple bitter/pale ale so you will have to wait longer to drink it at its best.bradfordlad wrote:PP - I know you're right......it's just in my nature to run like Usain Bolt before i can toddle, never mind walk!
I do take your advice very seriously though and will probably rein my eagerness in
Yeasty
Last edited by Yeasty on 10 Oct 2012, 00:05, edited 2 times in total.
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Post #24 made 13 years ago
Cheers Yeasty. I thought it would be the same but then the nagging doubt entered my head 
I just love strong american IPA's, that's why i got into the whole home brew thing. I hate paying £3 for a piddling bottle of Sierra Nevada etc. I am gonna mess about with the calculator and try and get as close to a 6% ABV as i can without having to do anything other than a straight BIAB. I think
One other thing. (always one other thing!)
The Hop Bill on the calc. I cant seem to get it to work
i was hoping for an IBU of around 70.
IGNORE ATTACHED FILE. Correct file in later post!
I just love strong american IPA's, that's why i got into the whole home brew thing. I hate paying £3 for a piddling bottle of Sierra Nevada etc. I am gonna mess about with the calculator and try and get as close to a 6% ABV as i can without having to do anything other than a straight BIAB. I think
One other thing. (always one other thing!)
The Hop Bill on the calc. I cant seem to get it to work
i was hoping for an IBU of around 70.
IGNORE ATTACHED FILE. Correct file in later post!
You do not have the required permissions to view the files attached to this post.
Last edited by bradfordlad on 10 Oct 2012, 01:30, edited 1 time in total.
Post #25 made 13 years ago
Will do ..got to cook dinner firstbradfordlad wrote:The Hop Bill on the calc. I cant seem to get it to work
i was hoping for an IBU of around 70.
I have attached a new recipe. If you get a chance to have a look it would be much appreciated.
Yeasty
Last edited by Yeasty on 10 Oct 2012, 01:16, edited 2 times in total.
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