Whole grape port

[JohnT]

Ack, stupid typesetting! The formula in that document that Salcoco listed is missing a set of parantheses, which makes it incorrect.

Here is what they meant (which, of course, is the same as A Pearson's Square):

X = V*(C-A) / (B-C), where

X = GAL BRANDY NEEDED
V = GALLONS OF WINE
C = FINAL ALCOHOL % WANTED
B = ALCOHOL % OF BRANDY
A = ALCOHOL % OF WINE

i found a little playing i needed... if you know the abv and ending residual sugar that you want, the just the pearsons square will no do it. i found that i made two pearson's squares.. one for sugar, and one for abv.

 

[Duster]

Ok now I'm confused.
I have 12 gallon of wine at 12.5%
I want to use E&J vsop brandy at 40%
If want to raise it to 15% I need 1.2 gallons of brandy?


Sent from my iPhone using Wine Making App

 

[Deezil]

I have 12 gallon of wine at 12.5%
I want to use E&J vsop brandy at 40%
If want to raise it to 15% I need 1.2 gallons of brandy?

Yes, sir..

 

[JohnT]

Something just occurred to me..

It looks like most folks are fermenting their wine dry, then adding sugar and fortifier after fermentation of the wine is complete. Is this what most people do?

I do it a little bit differently. I wait for the base wine to get to a specific brix level, then end the fermentation by adding a specific amount of fortifier. If I do my math right, I end up with a port with a specific abv and specific residual sugar. In other words, I try to use the natural sugars in the grape to sweeten my port.

Is anybody else doing this? If so, how do you end up doing the math? Seems like there is not single formula one can use.

My trouble is if I wanted to end up with a port having 8% residual sugar, I need to know the total volume of base wine that I am using....

But, if I try to determine the amount of base wine to use, I need to know the abv of the base wine (or brix).

I ended up creating almost a "double Pearson's square" and just played around with the total brix and base wine volume until I got it right. I am wondering if anybody else has a better way??

 

[seth8530]

I do.. Give me a few and I will explain.

 

[JohnT]

I do.. Give me a few and I will explain.

Seth... Any luck?

 

[seth8530]

Yeah, I just have not had the time to write it all down yet. Just to make sure we are all on the same page...

You want to know how must spirit you need to add to ensure that you hit both a target abv and sugar?

 

[JohnT]

Yeah, I just have not had the time to write it all down yet. Just to make sure we are all on the same page...

You want to know how must spirit you need to add to ensure that you hit both a target abv and sugar?

yes, given a fixed volume, base wine starting brix, desired abv, and residual sugar.

I would like obtain a recommended base wine ending brix, and proportions of base wine to fortifier.

 

[seth8530]

Cool, working on a solution. Thus far I have decided it will be easier to work in g/l land to designate sugar concentration instead of brix to make the math work out. Thus far I have managed to come up with an ABV equation which relates ABV to the change in sugar concentration in units of g/l.

 

[seth8530]

So after giving this a good luck I am not sure if this can be calculated by hand if you take into account what you want your final sugar to be after the spirit fortification addition. Right now I am playing around with writing a short script to try and solve it by running iterations.

 

[vacuumpumpman]

Here are some good conversion tables - let me know if these help at all ?

http://www.winebusiness.com/tools/?go=winemaking.calc&sid=7

http://vinoenology.com/calculators/fortification/

 

[seth8530]

Well, I have pretty much already solved for what those programs do. The trick I am having to deal with is figuring out how to make it work so that I can hit both a desired ending ABV and desired ending sugar.

 

[vacuumpumpman]

Seth
I always have to watch the hydrometer till I reach my desired ending sugar - then calculate how much white brandy to stop fermenation

Sent from my SAMSUNG-SGH-I747 using Wine Making mobile app

 

[Deezil]

You might have to write the math to solve for the 1, then use that answer to solve for the other... then code it to display both...

 

[seth8530]

Alright, I think I got it! I wrote up a script in matlab to solve.

The way the solver works is that it fist solves for the volume of spirit needed to reach a certain abv when you have a certain sugar drop.

Once that is done it checks to see if the spirit addition lowered your sugar concentration below your desired level (it will). Once that is done it increases the sugar concentration (final gravity) at which you add the brandy. Once that happens the ABV from the fermentation goes down so it then adds more brandy.

It keeps on doing this until it converges on a solution. I had to play around with it quite a bit since their are quite a few solutions that will work but many of them do not make sense...


If anyone is willing to take my code and turn it into something other than MATLAB please feel free to do it, but give me credit. The only other language that I can turn this into is FORTRAN .EXE that requires you to add a .dll library to your PC. In the Past my FORTAN programs on the forum did not really take off all that big and I suspect that is the reason why.

%% Program written by Seth Langford
% This program is meant for open use by anyone who needs to fortify
% beer/wine/mead
% If you use the code for your own programs please give me credit



GramsPerLiterEndOfFort=0;
LitersWine=23;
LitersSpirit=0;
SpritABV=40;
ABV=0;




%% paramaters for wine maker to play with
LitersWine=23; % how many liters of wine you have prior to being fortified
GramsPerLiterI=200; % The initial sugar concentration of the juice prior to ferment in units of grams per liter
SpritABV=40 ;% ABV of the spirit being used to fortify the wine
DesiredEndingGramsPerLiter=45; % Desired ending sugar concentration in units of grams per liter
DesiredABV=16; % Your desired ABV after fortification
%%
GramsPerLiterEndOfFerm=DesiredEndingGramsPerLiter; % intilazitoin stuff
while ABV < DesiredABV;


FermAlcohol=.05*(GramsPerLiterI-GramsPerLiterEndOfFerm)*LitersWine/100;
SpiritAlcohol=LitersSpirit*.01*SpritABV;
ABV= 100*(FermAlcohol+SpiritAlcohol)/(LitersSpirit+LitersWine);
LitersSpirit=LitersSpirit+.000001;



GramsPerLiterEndOfFort=GramsPerLiterEndOfFerm*LitersWine/(LitersWine+LitersSpirit);
while GramsPerLiterEndOfFort < DesiredEndingGramsPerLiter;

GramsPerLiterEndOfFort=GramsPerLiterEndOfFerm*LitersWine/(LitersWine+LitersSpirit);

GramsPerLiterEndOfFerm=GramsPerLiterEndOfFerm+.00001;
end



end
GramsPerLiterEndOfFerm
ABV
DesiredEndingGramsPerLiter
GramsPerLiterEndOfFort
DesiredABV

 

[seth8530]

Seth
I always have to watch the hydrometer till I reach my desired ending sugar - then calculate how much white brandy to stop fermenation

Sent from my SAMSUNG-SGH-I747 using Wine Making mobile app

Yup, but the issue with that is that you add brandy and then you change your sugar level because of the brandy you added in the wine. Pretty much what the script does is tell you at which gravity do you need to add spirit and how much spirit to reach a certain ABV and sugar level.

You might have to write the math to solve for the 1, then use that answer to solve for the other... then code it to display both...

That is kind of what I did. I tried solving it with a system of equations using pen and paper but for some reason I could not get a solution.. Thus, I applied the same logic you laid out but with numerical methods.

 

[sjo]

" I made a small side batch of wine just for use in port" Quote from JohnT so I am going to call this the JohnT method.

I started to make what I thought was a port using 8 gallons of frontenac grapes. I fermented grapes and added sugar until yeast died out. somewhere around 18%. There is a little residual sugar (sg1.08) I then used the johnT method and brought to 24% alc calculated. Added oak and is now aging.

My question is why stop fermentation by fortifying instead of letting it finish the ferment and backsweeten later.
Scott

 

[seth8530]

The theory is that the natural grape sugars will taste better or give a fuller wine than simply adding back sugar syrup.

 

[sour_grapes]

Seth: I know you have looked into this a bit. What's your take on the conversion between (and the relative advantages/disadvantages) of SG vs. grams/liter sugar? Is this as good a source as any for the conversion:
http://mpesgens.home.xs4all.nl/thwp/sugar.html ?

 

[seth8530]

I use this as my source for common wine conversions

http://www.brsquared.org/wine/CalcInfo/HydSugAl.htm

If it was not for the fact that most people make wine and use SG I would use exclusively units of g/l or brix. The reason why I like units of g/l is because you can multiply by your total volume of must and you can get the total mass of sugar in the wine. Which makes life a whole LOT easier if you like to make wine smart and calculate how much everything you want to add instead of looking at the hydrometer.

BTW, according to some math that I did you can relate the drop in g/l to ABV.. Ie (Initial g/l-Final g/l)/20 =ABV Or if you like this versoin better (Delta g/l)/20=ABV

The advantage of using SG is that it actually tells you the density of the fluid you are working with in g/cm^3. Thus if you know the mass of your fluid you can get the volume back out which is pretty cool.