Water calculations compared

[redwing_al]

Hi everyone. I was looking at and comparing some of the free, online water calculators for BIAB. Seems there is a lot of variance and I tested 5 different ones with specific, basic controls so that I was comparing apples to apples.

I have no idea of knowing which one is most accurate, nor do I know if it even matters. I'm trying to hit my calculations somewhere in the middle. However, it got me thinking.. I'm wondering if there is a way to crowdsource the knowledge? If so, I'd be willing to participate. Anyone have any thoughts on a crowdsourced effort? I would be happy to help if there was interest.

in any case, below is a comparison of 5 different online calculation tools that I found... Like I said, I dont know if the variance makes a hill-o'beans difference in the final output, but I'd like to know the difference of using a higher water calc versus a lower calc.

here is my comparison: https://docs.google.com/presentatio...oM4bY/pub?start=false&loop=false&delayms=3000

thoughts?

 

[wilserbrewer]

That's quite an unacceptable range of 3/4 of a gallon on only a five gallon batch.

I bet a beer that priceless's calculator is in the middle...cheers!

I'm starting to feel better about my nonchalant attitude winging it...with a little experience you can come darn close by increasing the boil on the fly, or topping up wee bit.

Interesting comparison...thanks.

Bottom line is pay attention to how much you actually have in the kettle, rather than what the calculator indicates you should have. Make adjustments if needed, perhaps sparge a pint or two if short, or boil a bit harder if over volume.

 

[doug293cz]

Can you post information on each of the calculator's default values for grain and hop absorption? These will affect the total water required. Also, can you post links to each of the calculators?

Brew on

 

[redwing_al]

Can you post information on each of the calculator's default values for grain and hop absorption? These will affect the total water required. Also, can you post links to each of the calculators?

Brew on

Hi I left the actual calculators out of the comparison because I am sure these folks worked hard on some of these interfaces and I wanted to spare them the criticism that folks may have. a simple search here or on the internet will get you to them for sure - and MORE...

However, the constant values for grain absorbtion: .045

I pretty much take all of Wilserbrewers advice on these BIAB forums and I did find that the Priceless calculations made the most sense for 'my' set up. http://pricelessbrewing.github.io/ although Beersmith told me 9.44G versus the 8.27 that Priceless recommended.. So, I think I used too much water on my last batch. I'll trust my instincts from now on and use the Priceless calculator to get me close as it seems to match what I have tracked.

What I dont know is the affect 9.44 gallons vs 8.27.. is it significant in brewing comparisons?

 

[pricelessbrewing]

Interesting comparisons. It brought an error to one of my formulas, apparently javascript doesn't like multiplications without a space between. Mash volume should be fixed now, and correctly matches green bay rackers (although mine is adjusted to thermal volume expansion at mash temperature)

Pulled up beersmith for the first time in awhile, which while a wonderful program sometimes it's just too difficult to use for me.

I can only assume I'm subject 1, which should actually be 7.72 Gallons. Also mines the only one I'm aware that cares about both kettle diameter, and volume size. (if you change a value and it's a decimal, make sure it remains 0.xx and not .xx, or the calculator gives up and won't update) I'll see if I can fix that next week, but might be beyond my grasps.

Subject 2 is probably beer smith? It doesn't account for hop absorption, and may have some hidden volumes? I have no idea why there would be any other discrepancies.

Would you mind releasing the names in a message? I'd like to look at them and see what they're including / not including in their calculations. My assumption would be that the ones greater than 8G total are defaulted to traditional losses to grain absorption rate, mash tun loss etc, which don't apply to a BIAB world.


As long as your final volume matches, that's what's important.
But having an extra 1.17 G is rather significant imo, that could be a 20% dilution if it was carried throughout the brew all the way to the post boil.

 

[wilserbrewer]

What I dont know is the affect 9.44 gallons vs 8.27.. is it significant in brewing comparisons?

An extra 1.2 gallons in a 5 gallon batch is tremendous, This calculator is a disservice. One would be better off without a calculator, falling way short and topping up with water.

Pulled up beersmith for the first time in awhile, which while a wonderful program sometimes it's just too difficult to use for me.

Me too, beersmith gives me a headache j/k

Also mines the only one I'm aware that cares about both kettle diameter, and volume size.

This is a great feature! When I first noticed the kettle width inquiry, I was like what the heck do we need that for...then I realized it was for a kettle volume check!

Mash volume exceeding kettle volume is a potential disaster, nice work!

 

[pricelessbrewing]

An extra 1.2 gallons in a 5 gallon batch is tremendous, This calculator is a disservice. One would be better off without a calculator, falling way short and topping up with water.

This is a great feature! When I first noticed the kettle width inquiry, I was like what the heck do we need that for...then I realized it was for a kettle volume check!

Mash volume exceeding kettle volume is a potential disaster, nice work!

Thanks .
I figured, calculating mash volume, preboil etc was rather pointless if you can't measure it easily. I have NO idea where 6.2 gallons is on my kettle without knowing how TALL that is. I highly suggest everyone buying a simple all metal ruler, aluminum or SS, whichever. Mine was like $3 from harbor freight for 4'.

 

[enkamania]

It's all in the settings, I ran numbers in both BeerSmith and the spreadsheet and came close.