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Volume into FV is always too low

Post #1 made 12 years ago
by dom
Hi,

I've done 3 BIAB brews now and each one I am under when draining into the FV. Sometimes more than others. Todays brew I hit my gravity targets (in fact that hasn't been the problem in all three brews) - its the volume. So I have tried the calculator, Biabicus and Beersmith side by side. Of course all three give me different instructions for starting volumes :-D
So todays brew I thought I'd give the Biabicus a go after reading a few of PistolPatchs posts on how more appropriate it is for BIAB than other software. As it happens it came out pretty low on the starting volume (nearly 4 litres less than Beersmith). I ended up with 19 litres into the FV when I was after 24.84. I'm happy to persevere with Biabicus to try and sort this - I just need to figure out where/why my volume is always lower than expected. I have attached the biabicus, calculator and beersmith recipe if anyone can help shed some light I'd greatly appreciate it.

I also am not totally sure the measuring thing is accurate even though I have a straight sided kettle, so maybe tomorrow I will measure out the quantity with a jug and measure it to see if it matches.

To my novice eye it looks like Beersmith is the closes because if I used its starting volume I'd be nearer my 24 litre mark with the extra 4 litres.

Cheers
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Last edited by dom on 11 Jun 2014, 07:22, edited 1 time in total.

Post #2 made 12 years ago
by PistolPatch
dom, post your actual .bsm file up. The BeerSmith numbers are actually based on those that we sent BeerSmith and they will match when you have things set up correctly. Your calculator and BIABacus files will also agree closely (except for a few numbers that in the Calculator that don't consider wort expansion and contraction) when set up correctly. There are several reasons why your Calculator and BeerSmith numbers aren't matching BIABacus but the easiest thing to do is post your .bsm file up and then I can explain things more easily.

Before doing so, also maybe do a search here on ".bsm" as I've gone through this exercise quite a few times and it always takes a lot of writing so some of the things you dig up might even help you to make the appropriate modifications in the files above.

For example, all the kettle efficiencies in the files above must agree and the VAW's. Once you have done that, then it is just a matter of correcting for some temperature/terminology/formula errors in the other programs (not the BIABacus).

Please do the search and let me know if you come up with some gold because otherwise it could take me some time to get back to you. Running behind on a lot of things atm.

:peace:
PP
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Post #4 made 12 years ago
by jhough
Dom.. not trying to treat you like a newbie .. Sure your total water reading is correct? I know with my last 2 girls still at home I get pulled away sometimes and have to correct with a sparge /protein rest step. I say this because Mash Volume is 9 litres more in estimated over actual.
J
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Post #5 made 12 years ago
by dom
at this stage of my BIAB career I don't mind being treated like a total Newbie :-D

I have just re-calibrated my pot and i reckon one litre = 8.42 mm
ie 30 litres= 242, 35 = 282, 40 = 322. As a result I have changed my kettle diameter in Biabacus to 39.8cm as that's the closest I get (its only .08 litres out here and there). I filled up my strike water to 31cm which is approx 39 litres. The Mash Volume I took was when I had finished the Mash - was this the right reading ? I presume you don't take a volume reading with the bag in the kettle, although thinking about his i don't see how the volume can go from 39 to 43 litres without there being something in the kettle (like grain). Whats the point of measuring volume with the grain in ? I can't imagine its overly accurate or useful ?

So I lost nearly 2 litres to my VIB - why is this out so much ? I did a 85 min mash, then a 10 min mashout then i squeezed bag.

Also my calculated evaporation rate is lower than estimated so something is a bit odd there. ie I'd expect if my evaporation rate is lower then when heating up to boil it would be slightly less water loss. So there's nearly 2 litres there unaccounted for.

There's 1.2 litres difference at VFO. It probably would have been worse if i'd had the burner on full like my last couple of brews but i decided to turn it down a bit as its a mental burner.
One thing I would say now that is going to affect stuff is my measured KFL. I stopped transferring when I saw trub coming through - however there still was a bit of beer in the bottom of the kettle and I probably could have got more out with a little trub in. Next time I will carry on transferring until I start to get air bubbles as I haev a ball valve and an elbow on the inside. So I reckon next time the KFL will be less.

So apart from the Mash Volume (which might be me misunderstanding what that is/when to measure it) and the KFL which is a bit higher due to stopping transferring a bit early all the figures should be right.

I am keen to just use Biabicus for brewing and use Beersmith for the timer and beer colour.

cheers
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Post #6 made 12 years ago
by alanem
Quote:
" I also am not totally sure the measuring thing is accurate even though I have a straight sided kettle, so maybe tomorrow I will measure out the quantity with a jug and measure it to see if it matches.

I was having great troubles with the same problem and decided to test the "reject shop" 3 litre plastic jug I use by weighing the water (1 litre of water at 4°C has a mass of 1Kg.) and discovered a huge difference in the volume I was getting, I was 1.2 litres short in 20ltrs using the jug.
I then weighed in 2 litres at a time into my kettle and marked my SS strip (Bunnings $3+) after each addition and I'm now confident I have a pretty accurate measuring system, then by altering some small calculations on biabacus and allowing for no calc stuff ups by me I now have my volumes etc pretty close each time
Cheers
Al
PS: also double and triple check your kettle dimensions as you don't need to be much out to finish a lot out
Last edited by alanem on 08 Jun 2014, 07:03, edited 1 time in total.
I used to spill more than I drink these days!

Post #8 made 12 years ago
by PistolPatch
Thanks for posting the bsm file dom. Only problem is that I am in the middle of doing a major re-install so have to reload Office, Beersmith etc etc and it might take me a few days.

Here's a few thoughts on your post #5 above...

Mash volume is measured with the grist in. Basically this acts as a first check on the brew. If it was say 15% out, you would be given your first warning that maybe something hasn't been measured correctly.

Your evaporation rate works on a formula that we wrote based on collecting a whole lot of different brewers numbers. It doesn't mean that you will get that evaporation rate. The formula is there to get you safely under way until you can better understand your own evaporation rate. Evaporation, especially if you brew outside can vary wildly from brew to brew so don't expect it to be a constant.

KFL is also there as a guide. You should not be trying to match that. In the final BIABacus, I've changed the loss formula so that it also looks at your hop bill and gravity etc as these things all affect kettle trub. Just drain your kettle until it starts to go cloudy.

Have a read from this poston. It will get you primed for understanding what I'll post next when I have things installed.

The BIABacus does colour and actually uses the correct formula! (Beersmith used to have an error on colour. I can't remember if it has been fixed in BS2). If you want to see the actual colour on your screen, even if the formula has been fixed, the colour will look different on every monitor you use. I have three here and they all look different.

:peace:
PP
Last edited by PistolPatch on 08 Jun 2014, 09:57, edited 1 time in total.
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Post #9 made 12 years ago
by dom
Thanks for that. I've had a read of a few pages of that post. Not sure what you're going to advise really... Maybe something about water being held back in the grain would make sense as one comment, that'd explain the loss post-mash however I'd have thought biabicus cater for that by default and take it into account.
Cheers

Post #10 made 12 years ago
by majorphill
Dom
Welcome aboard :thumbs:

The best way to calibrate your kettle is by measuring it. A volume is mathematically solveable with no chance of error. If your kettle is straight sided and flat bottomed enter the data into section A. If you have a concave or convex bottom enter the difference in section X. Your making it hard for your self by using jugs and weighing them. Measure it. :clap:

As PP says you measure the Mash Volume when the grain is in the water. It gives you a check that you have the right amount of water and the right amount of grain. That number needs to be close for the rest to follow.

As we don't have that number, we will assume it was right. 43.26l with your new measurement of 39.8cm.

Your VIB was 34.75 against the predicted 36.67. A difference of 1.76l. Somewhere in between puting the grain and water in and taking the grain out you've lost that 1.76. That suggests that either the water wasn't there to start with or it's still in the grain .. or .. the VIB measurement was wrong. I suspend my bag over the kettle and let it drain until I reach boil. I have tried squeezing it but I think all your doing there is speeding the process of getting the water out. I don't think you end up with more. If you pulled the bag and removed it immediately you -- may -- have left the 1.76l in the bag. Otherwise it may not have been there to start with. A mash volume would tell you which.

Moving on your VAW was lower than predicted by 1.2l. You have recovered 0.56l. :argh: As PP says evaporation is a dark science with too many variables. At this stage you are only 1.2 l lower than expected. Not too bad if you ask me. Your volumes are good and your gravities are good. Your on target. :shoot:

Then you lose 4 litres. :nup:

I normally do a 40l VIF brew and I lose 2 litres KFL. You've lost 6.5 on a 25l VIF. I think you may want to review your process at this stage ... and measure with care ... :cry:

But you've made great beer. What more can you ask. :thumbs:

Post #11 made 12 years ago
by PistolPatch
Another lovely post by the Major :salute:.

I think the big surprise in store for you dom, will be that all three programs will agree when you correct for the errors. (Didn't I say that above already???)

I think, even after I get everything re-installed on my computer, that before I write any more, it would be worth you studying the Clear Brewing Terminology (CBT) threaddom. (Thought that thread was linked in within one of the above links wasn't it?)

Have a look at post #9 of that thread which took several years to write. The first question (forget wrong formulas in other programs and they are rife) is to work out what the hell other programs mean when they give you a volume.

You wrote above,
Not sure what you're going to advise really...
Well, the first thing I am going to advise is that you understand totally what VAW means. Volume of ambient wort is the key number in a brew.

That is the critical thing to understand and your original files, from memory, do not have the same VAW.

The next thing I will say is that the three files you posted all have different kettle efficiencies so they al have different grain bills and this means that they can't be compared as liquor retained by grain is a big factor.

The next thing I would delve into is incorrect gravity and grain formulas from other programs. Basically that means that OG calculations in that other program are about 4% out on average.

After that, I would point out that, unlike the BIABacus, the water volumes in the other program are not defined properly. It is not clear if they mean volume at ambient or boiling temperatures. This makes another 4% difference. For example, 32 litres at boiling point is only about 30.7 litres at ambient. That's a 1.3 litre discrepancy straight away.

Unlike other programs, the BIABacus is very transparent. The terminology has taken years to work out and the formulas are very defined. The BIABacus is very, very clean.

And that is what I will be advising you so slow down and re-read every post above and any links they contain several times. Do that and you will become a master.

When you can post your three files again and they all agree, then you will be a master.

I'm uncertain now as to whether to post the answer once I have BeerSmith and Excel re-installed or leave you to post the answer yourself.

...

I think, for now at least, the aim of this thread should be for you to ask as many questions as you need for you to be able to post those three files again so as they all match.

Probably a better way to learn I think :think:.
Last edited by PistolPatch on 08 Jun 2014, 23:13, edited 1 time in total.
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Post #12 made 12 years ago
by dom
Thanks for both replies. As it happens I was referring to the CBT thread during my brewing session and I have it bookmarked. Sounds like I'll try suspending bag next time and also look at my transfer technique. I'll have a play around with the spreadsheets and calculators to figure out what's up.
Cheers

Post #13 made 12 years ago
by jhough
Dom ...We are all just trying to help.
Major,,, WHAT A GREAT REPLY !! I learned a HELL OF ALOT from that reply..I now have bookmarked it !!
J
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Post #15 made 12 years ago
by dom
PP, I re-read your post (you will be pleased to know !) and looked at post #9 (which I did not look at closely when reading all the other CBT posts) and actually its a useful diagram as it shows you on one page where the largest volume losses are. So that guides me (and others) where to look - although I have a headstart because of Major's post which hints at where my losses are.
I am going to focus on getting the Calculator and Biabicus to match to start with (and then worry about Beersmith).
VAW - so the way I understand VAW is this (and referring to the graph on post #9):
VAW = The Volume of Ambient Wort = The wort that has been through both heating and chilling process and is chilled to fermentation temperature. ie it has expanded and shrunk during this process at different stages (ie expansion due to grain, heating, shrinking due to evaporation and chilling). VAW - KFL = VIF.
I believe my two areas to look at in my process are the water retention by the grain (I'm going to alter my process to suspend it over the kettle as advised by Major), and my KFL. I will tweak my tap drain elbow for this.
I'll keep you posted after my next brew how this went. In the meantime I will check my errors in the Calculator and get it to match Biabicus - I thought maybe The Calculator was using different formulas and thats whay it wasn't matching but it sounds like User Error.

Cheers and once again thanks for your help - it is appreciated.

Post #16 made 12 years ago
by dom
OK - after reading a thread about using a hopsock affects grain volumes I have removed all advanced trub management and now The Calculator and Biabicus are almost matching. The hop bills are the same and the grain bill is only out by 200g but I can't see where the discrepency might be. So as a result the starting TWN is different too. I suspect its some other setting in the Biabicus that's causing this as there isn't anything left that i can see in The Calculator to alter ?

I've uploaded the two nearly matching files if someone could help identify whats causing the missing 200g grain. I thought about what else touches the wort and removed everything i can think of in Biabicus - ie immersion chiller and koppafloc but that hasn't altered anything.

cheers
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Post #17 made 12 years ago
by PistolPatch
Nice work dom :peace:,

The big error in The Calculator formula is one of terminology - it didn't really deal with expansion and contraction at all. See how in The calculator it has an end of boil volume of 28.98? And then you have 24.84 Volume into Fermenter and 4.14 Kettle Trub and Buffer? We actually need to shrink that 28.98 to ambient (VAW).

Now lets convert that volume at boiling to the ambient using the tool on the second sheet of the BIABacus. The 28.98 becomes 27.86 L.

Now in Section B of the BIABacus I am going to type that 27.86 L in as desired VIF (hold on, this will make sense in a sec ;). Now in Section X, I am going to set the KFL to 0. This effectively means that the VIF in Section B is now the VAW.

One last thing, in Section X, I am going to change the kettle efficiency to 79% so as it matches The Calculator.

Now we have 5736 grams in The Calculator and 5715 grams in The BIABacus. Any discrepancy like this will just be due to the BIABacus using more precise rounding.

....

I better get back to work but now in BeerSmith, you need to set up an equipment profile that has "batch size" of 27.86 and set your 'Loss to Trub and Chiller' to 0 and your 'Brewhouse Efficiency' to 79%. Then you need to scale the recipe to the new profile.

After that you then need to do one more thing but see how you go with the above first. If you have any troubles, just leave it and I'll have a crack in a day or so.

:peace:
PP
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Post #18 made 12 years ago
by dom
I think I need a lobotomy after reading that ! I will have to re-read a few times and figure out why you're doing all of that. Was this exercise to show how to get The Calculator to match Biabacus or are you saying i need to make these alterations to Biabacus each time I want to use it ? I'm hoping you'll say its just to show the differences between the two spreadsheets :-D

I'll give beersmith a crack too. I do appreciate your help in this - I can see you're busy on this forum a lot and probably answer questions like this all the time. Having said that, you telling me to go off and read a load of those posts actually did help me think about it all and that picture is great for instantly showing your volume losses.

cheers

Post #19 made 12 years ago
by dom
So even though the grain amounts in all three are pretty much matching the amount of water needed to start with is different.
Biabacus has 39.12 litres for 5715g, The Calculator 40.56 for 5736 and BS has 40.33 for 5716g. I guess I'm interested in why Biabacus is over 1 litre less in TWN than the other two ?

Actually flicking back to the original Biabacus before we turned it into a Beersmith version TWN was 40.13 - which is same ball park as the other two.

urgh now its doing my head in.
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Post #20 made 12 years ago
by Rick
These formulas are not meant to be exact. You have to ask yourself why balancing the three matters to you? I'd pick a program and then focus on making beer with it. While you're fiddling with numbers, beer isn't being crafted.

It's easy to get wrapped up in the minutia of it all, but the way I see it everything looks close enough. You seem to be looking for a greater level of precision than can be found in brewing.
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Post #21 made 12 years ago
by PistolPatch
Okay, remember I talked before about shrinkage and expansion and terminology? The BIABacus is the only one that gets it right...

In Beersmith, the Total Water Needed is based on boiling point, not ambient. The Calculaor's 'Water Required is...' also a hot volume.

Let's turn thew 39.12 L of TWN in the BIABacus into a boiling point volume. Once again, I will use the unit conversion sheet of the BIABacus. The 39.12 L expands to 40.69 L.

You are now pretty much balanced. Any remaining discrepancies are due to BIABacus using metric formulas and a more precise ambient to boiling point formula.

Just as a matter of interest, notice how the BeerSmith and BIABacus volume into boil both match pretty much? BIABrewer gave the formula to BeerSmith for BIAB liquor retained by grain. Unfortunately they didn't ask and I didn't have time to check that they had interpreted the temperature part correctly.

...

As a matter of interest, in the final release of the BIABacus, I have put in an adjustment for Liquor Retained by Grain just like we already have for the Strike Water Temperature in Section X. This way, a small batch brewer can set a much lower liquor retained by grain figure than a large batch brewer. (A small bag is easier to drain than a large bag basically.)

Main thing to take on board is what Rick was alluring to and I think I probably mentioned above. Numbers are tools, not Gods. You should not be worried if your losses and evaporation do not match the estimates. They shouldn't match them exactly. What you need to do in the early days of brewing is record your numbers and see how your averages add up. If you are consistently falling short in some area, then we need to look at why.

Anyone that tells you they always match their software are kidding themselves and you. It is impossible. Even the large commercial breweries have to make constant corrections on each batch. The default figures in the BIABacus are aimed at hopefully giving you a bit more beer than expected. This is the safe and sensible approach.

:peace:
PP
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Post #22 made 12 years ago
by dom
Thanks for all of your replies. Its great to see people happy to point people in the right direction. Initially I set out entering the recipe in all 3 software apps as I was unsure why I only ended up with 19 litres in fv rather than 24. However as pointed out to me its more likely to do with my brewing process than any of the software - and I will tweak that following some top tips given here. What has also been interesting is also understanding that beersmith calculates BIAB differently from Biabacus.Also interesting to know was the differences of the calculator. So I'm pretty happy, I think next time I will use Biabacus again as intended and I will enter the hop sock entry to reflect my brew.
PP - which forum section will the Final version of the Biabacus be in when you release it as I'll keep an eye out. ?
Thanks once again and cheers !

Post #23 made 12 years ago
by PistolPatch
Good stuff dom and thanks for taking the time to 'tick' your thread :salute:.

As far as possible, I think the 'click link' in the BIABacus (two lines above Section K) should always get you the latest 'official' version. So maybe bookmark this thread in your browser and make sure you subscribe to it. It will always be a sticky in the new brewers forum as well. At the moment, the BIABacus is progressing much faster than I can write the help and so that is why we are still relying pretty much on one on one help atm.

Can't wait to release a final pre-release BIABacus and write some great help on it and had set aside quite a lot of time (actively taken off work) to do so in the past and coming week but instead ran into computer problems. C'est la vie :smoke:.
Last edited by PistolPatch on 12 Jun 2014, 18:00, edited 1 time in total.
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Post #24 made 12 years ago
by dom
Hi. I thought i'd post an update seeing as you all took some time to help me. I did a SMaSH brew at the weekend and all my volumes and gravity were spot on or better. The only one that was under was my VIF by about 1 litre. My SG was over though and I could top up by 1 litre in the FV with no problem. My KFL was about 3 litres this time and I've made another adjustment to my elbow as I reckon I can get a bit more out of it. So, its going pretty well now, and all of this was from the Biabacus, I only use Beersmith for the timer.
Cheers!

Post #25 made 12 years ago
by PistolPatch
Great! That is the way you want it. Topping up in the fermentor is much better than ending up with weak wort. Perfect!
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