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ABV Calc and gravity calcs when using Maltodextrine

Stevedkiwi

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Keen to buy the software but would like to get an answer to the following queries first.

1. The software seems to calculate ABV excluding the .4 0r .5 % added by priming. e.g. an OG of 1.042 and FG of 1.012 results in an ABV of 3.9% whereas I believe it should be around 4.3- 4.4% to take into a/c the fermentation taking place due to priming.

2. The OG and FG estimates do not seem right when using a low fermentability sugar such as mlatodextrine.

I am testing the software against a real brew recently completed with the following recipe

Coopers Australian pale Ale kit 1.7kg
Dextrose .5kg
Light DME .25kg
Maltodextrine .25kg
Kit Yeast

23l batch (Extract)

Since Maltodextrine is not listed as a grain and is in the misc table then it does not contribute to gravity estimation in BS2 so I get OG 1.035 and FG 1.005 (Which seems very low anyway if the OG is 1.035, I would have expected FG around 1.009 or so)
In reality of course maltodextrine will increase both OG and FG by almost the same amount due to its very low fermentability.

Actual gravities measured in the brew were  1.042 OG and 1.012 FG


I tried choosing Lactose from the grains table instead as I guess it has a similar effect to maltodextrine but this gave an even weirder result, lifting OG but decreasing FG !!!

I have attached the recipe

Thanks

Steve D
 

Attachments

  • Example for query.bsmx
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Strange that no one seems to want to set me right on these questions. I would have thought there is a pretty definative answer to both.

dont mind if the answer is that I'm a goose and "missing the obvious" but really would like an answer !!

cheers

Steve D
 
Steve-

You are right on both counts. 

Although most people use closer to 1/4 lbs of corn sugar, which is more like 0.2-3% ABV.  But, still you are correct that BS doesn't add that extra % (whatever it might be). 

Agreed, that maltodextrin is not calculated for. 

Not much more to say than that. 
 
OK so thanks, ...... at last a reply  :) :)

But to labour the point.

1. If one is trying to make to style, then surely an accurate (Or near as possible) ABV is important.

2. M/dextrine is used extensively in brew enhacers such as the Coopers products, and lactose is , (as I understand it), a key ingredient of Bristish Mllk stouts among other styles. So why dont software products support these ingredients correctly ???? (especially if they list them to start with !!!)



A local (Australian at least) and free, software, (excell spreadsheet based) product, seems to cope with both these issues admirably. Why cant global products like BS2 do likewise ? (dont get me wrong I like the look of BS2 and its not alone in (seemingly) getting these things wrong)

A posiible answer on point 1 (ABV) is that the BJCP guidelines for ABV exclude the effect of conditioning, but somehow I doubt that.


WRT the less fermentable sugars I am at a comlpete loss. Seems to me a glaring fault which then calls into question the whole product. Again I stress that as a new brewer I may be way off the mark. but if so, please someone correct me !!!

Tks Steve D
Steve D
 
Steve-

1.  Theoretically, yes.  But, 0.25 - 0.5% ABV error isn't much to write home about.  I worry about ABV in 2-3% ranges: session beers (3.5%), regular beer (5%), stronger (7%), strong (9%), and then above.    Because of various process variations that you can't control, you can't really predict the final gravity closely enough to predict ABV down to 0.25% anyway.  So, from a practical standpoint...its really a moot point. 

Also, again the 0.5% ABV represents a carbonation level of essentially 4 volumes of CO2.  That is right at (or beyond) the limit of many bottles.  So, that much sugar could cause bottle-bombs.  4 volumes is a LOT and would make for a VERY foamy beer that would be difficult to poor.

2.  The maltodextrin (or other unfermentable that would elevate SG) is potentially more significant...for the reasons you list.  Again, though...at least here in the states...its not THAT common of a homebrew ingredient.  I would venture to say that MOST US brewers go their entire hobby life without ever using it. 

Granted you are not in the US, and I know the Coopers kits are quite popular in Aus and NZ (regardless, I don't know that I've ever read a recipe outside of kits that include M/dextrin).  I have many friends in or from both countries.  In fact, I just got back from a 3 week business trip in Auckland (acknowlging that Auckland is sorta considered its own country separate from the rest of the populus).  I, also, spent two weeks on the South island back in January.
 
Tks Tom, hope you enjoyed your visit to the Shaky Isles, you yanks are always welcome, as long as you bring Money !!

my priming is based on the reccomendations of Coopers and sundry local forums etc etc. e.g 1 tsp of sucrose or preferably dextrose per 330 ml bottle or 2 per 750 ml.
No doubt bulk priming is  a better idea but local opinion seesm a bit divided on whats best and any way, bulk or bottle primed, the amounts would be the same as would the effect on ABV.
The three brews I have done so far seem fine CO2 wise. Not exploding and not too frothy.


I guess I understand that m/dextrine is not used extensively but it certainly crops up here in various "enhancers" and I am certain that lactose appears in many recipies for milk stouts.

Just seems wierd to me that software which copes with so many variables, scenarios etc cant (doesnt) tackle this issue, especially if the ingredients are listed.

Anyway enough whinging. Still like beer smith overall as a package, definately the slickest look and feel out there, but for now I'll be sticking with an Australian spreadsheet app developed by an enthusiast, that copes very well (And seamlessly) with the above points

Thanks again for replying.

Steve D
 
I'll be back several more times this year.  It's a beautiful country.  I'm there on business, but I get a few chances to see the country side---and VINYARDS.  Next time, I hope to visit some local brew pubs.  If you have recommendations  for the Auckland area...please pass along.

 
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