Equipment tuning issues

OkanaganMike

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New to the site however I've been playing with recipes here for a few months and just never tried getting my beer nerd brew day info correct. I'm having trouble fine tuning my equipment profile and understanding what factors affect the preboil amount. Don't know if this helps figuring my issues but I BIAB in a keggle and have figured most of my numbers by entering past brews into the brew day and going back and forth tuning them so the site hits my numbers I've recorded.
I've figured my grain absorption is between .5 and .6 qt/lb and this typically gets me to what my starting water amount was in the brews. Problem is the preboil water amount seems about a 1/2 gal lower than what I physically have had in the keggle and wonder if anyone can help me or point me to a tutorial that explains everything.

Eg: 11.88lb grains into 8.9 gals of water. BF preboil says it shopuld be 7.4 gal however I had 7.9 gal.

I've tried to figure it out myself for the last few days playing with the numbers, reading the forum and FAQ and know I must be close, just not quite there yet and need someone to "talk me off the ledge" before I say to hell with it. Could it have something to do with the kettle dead space? I haven't played with that yet.
Sheesh!
 
try adding more to an other amount for a loss, do this then pick quick water calc until you water amount is correct
 
try adding more to an other amount for a loss, do this then pick quick water calc until you water amount is correct

I either don't understand or I don't think that can be right. You see, I adjusted my grain absorption to .5 so I hit my starting water very close to actual amount; but then when mash is complete and I drain the grains, the preboil amount is about 1/2 gal short on the site to what I actually have in the keggle. Adding an additional loss will result in a higher discrepancy (loss) to what is actually in preboil amount in the keggle.

Playing with the grain absorption value will result in skewing my starting water amount so I want to avoid that.

I guess my question is what factor(s) will change my preboil amount without affecting my starting water amount?
 
if your starting water is correct and your preboil amount is not somethings defiantly wrong with your settings
 
Just change your settings to what your seeing in your brew pot. If you end up with more then your pre boil amount adjust by that amount or boil for longer.
 
Just change your settings to what your seeing in your brew pot. If you end up with more then your pre boil amount adjust by that amount or boil for longer.

Yeah I figured I could fudge it but was hoping to dial it right in properly. Thanks guys.
 
Yea that's how I've been adjusting my numbers by what results I'm getting in pot. Let's say mash in = 26lt grain = 4kg sparge = 5lt and pre boil post mash= 24lt then there you've got something to work off to adjust your pre boil settings. Then let's say I boil for 75 min and ending boil = 21 and then into fermentor post chilling = 20lt I can adjust my post boil settings to account for boil off and trub losses along the way. Then I add back my 1.5 lt for my starter that I've pre made and just pitch the whole lot. Sorry for using liters and not quart and gallons not savvy in them terms.

To tell you the truth I don't even have exact precise measurements for this I just know that the weld Mark half way up a Carlton United keg is 25lt and the bottom edge of the top ring round the keg is 30lt I use these marks on inside of keg as volume indicators. And I know volume into fermentor as its got liter increments up the side.
This is my system settings of losses for this setting on average.

Practice makes perfect in my case mmm perfect not exactly :oops: that's overstating but happy with what i can expect in the fermentor gravity wise and volume wise. Cheers mate enjoy :)
 
Guess I'm just a bit disappointed as there isn't a proper way to dial it in exactly for consistency, at least not one I can find. Been brewing for a good few years and up to now have never really been too concerned with the beer nerdy stuff. If it tastes good it was good enough for me. But now I've got experience, joined a homebrew club and I wanted to take it to the next level and get'er all dialed in so I can play with recipe development, gravities, efficiencies, and actual ABV and IBU (though they're never spot on anyways without a lab).

Don't really want to extend my boil time by 30minutes just because the program can't give me the proper preboil amount. Must be a glitch in the programs calculations. This may be a question for the techy guy/gal who developed these calcs.....

If the starting water amount is dictated by the grain absorption and weight of the particular recipe's grain, what factor dictates the preboil water amount? Is it solely the boil off rate and target batch amount? I change the grain absorption amount from .5 to 1 and the damn preboil amount doesn't change; how does that make sense? I understand the boil off rate provides the preboil target amt but there is a missing link in the equation between the starting water, grain absorption, and the very next step which is how much water you have in the pot after the grains have absorbed what ever water from your starting amount and have been drained and removed.

My suggested fix would be to have the ability to manually over-ride some of the fields in the calculations such as starting water amount and preboil amount and then have the program calculate the (gravity etc) numbers based on those modified relationships. It kind of a logic thing that makes sense in my head and not sure I've verbalised it adequately. I'm not a huge math guy and even less of a computer programming guy but this kind of seems like it wouldn't be to hard to figure out how to do if it was passed to the site developer and would improve the sites accuracy. :cool:
 
all I can say is the site works fine, I hit all my numbers right on every brew. it does take a while to get dialed in and not all beers are the same, the only way to completely get dialed in fast is too brew th exact same beer over and over, other than that you just have to fiddle with you recipe, your settings in your profile
 
I'm not on the pay roll or anything but I'm happy with the Brewers friend recipe calculator equipment calculator and advanced water calculator heck even yeast propagation calculator. Yep there are things I ignore just because my equipment and my brew standard doesn't need specifics I mash in my kettle so if strike temp is low (which I calculate for) I can bump it up with a quick burn. But then again it does take some stirring and some checks with my not so reliable temp meter to hit stable temps:p. Sorry to say but i use Brewers friend recipe calcs as a general template of how brews gunna go but I observe everything I see and write it down in a book and use this as my tweeker. But as we have found its all variable and as Ozark's has said replication is key! I'm not sure I could replicate last recipe! Now that in my opinion is a master BREWER. I switch around to quick I'm not really set in my brewing ways I'm exploring all the time and don't stop to brew two beers back to back at a time :). Homebrewing is good for that I don't need to brew for public I brew for me:D. Yep selfish:oops:

But in the end I hope,you get it sorted mike it can be a frustrating hobby:).
 
Thanks for the advice guys! I hope I didn't make the impression of having my panties all bunched up. Just kind of frustrated trying to put together this puzzle and making adjustments that don't change what I think they will change. I think OMB nailed it with doing the same beer over and over dialing it in a little each time too. I have a couple of house beers I make on a regular basis and will try to pay closer attention to those ones to see if it helps.

Cheers!
 
Just to answer one of your questions the preboil amount is affected by most of your system data entries. Mash tun dead space, boil kettle losses etc. give the program a chance. I know where you are at. I went through this when learning the software too. Sometimes just going to the "frequently asked questions" will give you your answer.
 
Just to answer one of your questions the preboil amount is affected by most of your system data entries. Mash tun dead space, boil kettle losses etc. give the program a chance. I know where you are at. I went through this when learning the software too. Sometimes just going to the "frequently asked questions" will give you your answer.

Yes, it's based on your input as well as your desired preboil volume.
 
Mike, I'm not sure exactly where / how you're tweaking your numbers, but I suspect you may need to work backwards rather than forwards? The quick water calcs will work out the required strike and pre-boil volumes based on what happens after the boil starts to ensure the target volume (fermenter or kettle depending on your setting) is achieved, e.g.:
  • You want 21 litres of wort in the fermenter, kettle dead space may be 2 litres therefore post-boil volume will need to be 23 litres total in the kettle post-boil
  • Boil-off may be 4 litres/hour therefore for a 1 hour boil the pre-boil volume will need to be 27 litres to get 23 litres post-boil
  • Grain absorption may be 1 litre / kg, therefore for 5kg grist to hit 27 litres pre-boil you'll need 32 litres total strike water (including sparge if you do one)
Metric/imperial units obviously don't matter for the example. But it sounds like you might be taking your actual strike water then trying to tweak it to hit a theoretical rather than actual calculated pre-boil volume?

Sorry if I've misinterpreted your question, but otherwise I hope this helps.
 
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Thanks Meddo. I totally get what your saying but what I'm trying to do is tune the numbers in my profile so I hit the volumes I'm physically getting with my equipment from past brew experiences.
The disconnect for me is the relationship between the starting water amount and the preboil amount and trying to match it to my numbers recorded from past brews. I've even thought about the 4% heated volume coefficient but without success. You see, if you adjust the grain absorption, it changes the starting water amount and I've got that part nailed. ;) Unfortunately, the preboil amt is always higher in the keggle than what I'm supposed to have based on the data. o_O Don't feel like adding an extra 30-45 mins to boil time for this discrepancy so am trying to figure out the why's and how's. Seems to me its only the grain absorption rate that affects these 2 numbers but they dn't work in unison. Maybe its because I BIAB and everyone else that are able to nail their numbers are 3 vessel with sparging?
 
So just to get it clear in my head, your total mash water volume is correct, and your final fermenter volume is correct, but the pre-boil volume is out? If so then the boil-off rate and the kettle (trub) loss volume are the other variables that you can adjust.

Or your total brewhouse efficiency is slightly out.

Can you screen-shot your equipment profile parameters and the example/test water volumes from your latest tuning?

My experience (limited as it is) is that the calculations do seem to be correct in theory when tuned properly, so I suspect that there is just some slight further tweaking required to get yours nutted.

Cheers,
 
I haven't thought about playing with the boil off rate as I measured it and set it to what it actually is. Can't see how this could make the difference (but will play with it to see) Seems to me the absorption rate sets your starting water amount, then subtracts that absorption rate from the starting amount equalling your preboil amount right?

Brewhouse efficiency may be out as I'm getting better than 70% on some and less on others (bigger beers). Don't see how that can be a factor for the preboil amount but I may have pigeon holed my vision of the problem and have to stand back for a while fr a new perspective.
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Hey Mike, did you get anywhere with this?

If not, I suspect it may be due to an error in the way BF treats kettle deadspace - see here:

http://www.brewersfriend.com/forum/threads/pre-boil-gravity-calculation-error.3403/

Basically it appears to be treating the deadspace as additional boil-off volume, and as such concentrates the sugars and AAUs rather than losing them in the step between post-boil and fermenter volumes and SGs. This caused me to miss the OG of my latest brew by 8 points, despite the conversion efficiency, pre-boil SG and volume, and post-boil volume being spot on as predicted by BF. This actually appears to have happened on all six brews I've done using the BF recipe builder but I haven't previously had the volume measurements available to isolate the problem.

If you've been working backwards from actual OGs it may have been carrying that deadspace error through to your pre-boil volumes?
 
Possibly. I'm working on improving my patience levels but in all honesty I've kinda stepped back from this as it was hurting my brain trying to figure it out. Reckon I'll run a few more taking careful notes and try to go back and see if I can dial it in better.
 

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