View Full Version : Complete list of formulas?

pugsquasher

07-06-2009, 01:38 AM

Hello everyone! It's time to play everyone's favorite gameshow: Stupid Questions from Stupid People! Okay, not quite, but I do think it is a pretty assanine inquiry that I am about to make. Simply this: for whatever reason, I cannot get the mead calculator to work(aside: graphing calculators never liked me either). Therefore, is there a complete listing of formulas for calculating all necessary factors in the process(pretty much everything in the calculator, plus a few other useful tricks)? Any help/ridicule(and of course the usual advice to use the search function) would be greatly appreciated.

Cheers,

pugsquasher

Medsen Fey

07-06-2009, 09:20 AM

JamesP's mead calculator is an awesome tool, but it takes some practice to get comfortable using it. If you haven't read the Calculator Help Page (http://www.gotmead.com/index.php?option=com_content&task=view&id=816&Itemid=158), it might be worth a try.

Shanecb

07-06-2009, 09:06 PM

I actually think it would be pretty useful to have some formulas as well, if anyone has them. Mostly for calculating things when not near a computer/not available.

wayneb

07-15-2009, 06:03 PM

Although I like JamesP's calculator, I understand that it takes some getting used to. I also use Hightest's Mead calculator spreadsheet, which can be found on his website: http://home.comcast.net/~mzapx1/

If you are more familiar with excel spreadsheets, that one might be more user friendly for you.

CBiebel

07-15-2009, 10:43 PM

Although I like JamesP's calculator, I understand that it takes some getting used to. I also use Hightest's Mead calculator spreadsheet, which can be found on his website: http://home.comcast.net/~mzapx1/

If you are more familiar with excel spreadsheets, that one might be more user friendly for you.

I did notice, while working on my braggot, that the mead calculator doesn't have any listings for malt extract in the "additional sugars" section.

pugsquasher

07-19-2009, 06:52 PM

Okay, we're getting closer, but not quite there yet. Some of us(namely, me.), do not have Excel on our computers, so a spreadsheet doesn't help much. Also, as Shanecb pointed out, having the necessary formulas in hard copy is very useful when you're not near a computer. Besides, I actually prefer to do the math myself, that way I can be sure that the calculations are accurate. The information we seek exists obviously, you can't write a calculator program without the math being written out somewhere previously. I'm willing to keep looking, and if I find what I'm looking for before somebody else does, I'll be sure to post it here for everyone's benefit.

Cheers,

Harley

akueck

07-19-2009, 07:19 PM

The basic concept that the calculator is based on (I assume, correct me if I'm wrong) is that each sugar source adds some amount of sugar, which is then mixed into water (or whatever), and you can compute the expected Brix/SG of the solution. 1º Brix is supposed to be 1% sugar by weight. Each sugar source is assigned a % sugar by weight (which you can change if you like, but there are default values based on literature). Add up all the sugar, divide into the total, and bam there you go. For example, a fruit with 5% sugar contributes 1 lb of sugar for every 20 lbs of fruit. If you smash all this into what we will assume is water (but you can change that at the top of the calculator too if you like) to a total volume of 1 gallon (which for easy numbers weighs 8 lbs), the Brix is 12.5 (1/8 is 12.5% sugar by weight is 12.5º Brix). Now, my numbers are rough because I just rounded everything, but the calculator comes up with 11.94 Brix for 1 lb of sugar in 1 gallon total volume so you can see that it generally works something like that.

JamesP

07-20-2009, 07:26 AM

Some formulas are simple and direct:

%ABV = BRIX/1.8

%ABW = 0.8 * %ABV

degC = 5*(degF-32)/9

degF = degC*9/5 + 32

8 gravity points per pound of honey in 5 US gallons (this is an rough average)

assume Baume = %ABV (not quite true, but near enough)

Some are not:

To have a formula for SG/ABV or SG/BRIX, there are many models and assumptions that under-pin these formulas, because you start with "water" at sg=1.000, add honey/sugars to some SG, which then ferments to potentially LESS than 1.000 due to the specific gravity of the Alc and is a non-linear equation, and varies depending on yeast, etc, etc ....

One way to determine a formula for the SG/ABV is to use a spreadsheet to do a linear regression or polynomial solution to the SG/ABV data from your hydrometer, and come up with something like

%ABV = 139.706 * SG - 140.219

From the Internet, Ben Rotter has some wine making formulas, and I like

BRIX = 220(SG-1) + 1.6

Temp correction for hydrometer (SG correction) for 59F (15C)

= 1.313454 - 0.132674*T + 2.057793e-3*T*T - 2.627634e-6*T*T*T

pugsquasher

09-20-2009, 11:03 PM

... 1º Brix is supposed to be 1% sugar by weight.

... If you smash all this into what we will assume is water (but you can change that at the top of the calculator too if you like) to a total volume of 1 gallon (which for easy numbers weighs 8 lbs), the Brix is 12.5 (1/8 is 12.5% sugar by weight is 12.5º Brix). Now, my numbers are rough because I just rounded everything, but the calculator comes up with 11.94 Brix for 1 lb of sugar in 1 gallon total volume so you can see that it generally works something like that.

thanks for that, akueck.

One small question on percentage of sugar in the must and potential alcohol by volume(PABV): Is 1% sugar at the start equivalent to 1% PABV? or is there a conversion that needs to be done to get that data?

And thanks to everyone else for chiming in with additional info and input.

Cheers,

Harley Williams

akueck

09-20-2009, 11:35 PM

1% sugar does not come out as 1% PABV. I think it's roughly 2º Brix per % alcohol, but that approximation gets worse as Brix goes up. If you have a triple scale hydrometer (the most common ones are), then you will have a scale for % sugar and another for % PABV so you can compare the numbers. The rough number Brix to SG conversion is 0.004 on the SG scale is 1 Brix, so a change in SG of 0.008 is about 1% ABV. Again, these are just easy-to-add estimations so you can be more accurate with the mead calculator.

meadmonkey

09-21-2009, 09:40 PM

http://www.grapestompers.com/calculations.asp I have a lot of luck using these guys calculators very straightforward

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