Home Brew Forums (http://www.homebrewtalk.com/forum.php)
-   Brew Science (http://www.homebrewtalk.com/f128/)
-   -   Speise Calculator (http://www.homebrewtalk.com/f128/speise-calculator-356177/)

 Pommy 09-23-2012 07:51 AM

Speise Calculator

2 Attachment(s)
A nice easy one for the members who are clearly far more intelligent than I. I was trying to put together a speise calculator but after tying myself up in circles and making things worse I thought Id get some advice from the scientists amongst us, algebra never was my strong point :o

I have attached a pic of the formulae as well as one using numerical data if you can look for what I have got wrong. I was working from Braukaiser's info here: http://braukaiser.com/wiki/index.php?title=Accurately_Calculating_Sugar_Addit ions_for_Carbonation#Speise

 Pommy 09-23-2012 07:58 AM

1 Attachment(s)
This one might be a bit easier to follow (took a screenshot to show the references)

 GilSwillBasementBrews 09-23-2012 09:14 AM

Speise reserved for priming = 12 x gallons / ending numbers of OG before yeast pitched

This was the formula I came across when I was searching for a simple equation to figure it out.
Used it a couple times with no issues.

 Pommy 09-23-2012 10:13 AM

Thanks for that Gil, I am putting together another spreadsheet at the minute using my own calculations so that it makes a bit more sense to me than following others, just how my brain works :o I'll use that as my guide then try to build off of it. Once I get that sorted I can add formula for temp corrections etc. Where does the 12 come in? :drunk: Just an approximate for converting across measures?

 TNGabe 09-23-2012 12:50 PM

Quote:
 Originally Posted by GilSwillBasementBrews (Post 4437229) Speise reserved for priming = 12 x gallons / ending numbers of OG before yeast pitched This was the formula I came across when I was searching for a simple equation to figure it out. Used it a couple times with no issues.
What do you mean by ending numbers of OG? Last two digits? Of the OG of wort?

There is a diiferent formula in 'Brewing with Wheat' with a few more inputs. I've destroyed the math brain cells over the years and like the simpler option!:mug:

 GilSwillBasementBrews 09-23-2012 09:01 PM

I'd your OG is 1.054 you would use 54. So it would be

12 x (5/54) =spiese

12x(0.09259259) = spiese
1.111 gallons of spiese needed
Edit*. ^
Quarts not gallons

 Pommy 09-23-2012 09:46 PM

1.111 gallons sounds like a lot? would it be quarts?

 GilSwillBasementBrews 09-23-2012 11:44 PM

Yeah sorry my bad. Qt. not gallons. That would be a considerable amount.

 Kaiser 09-24-2012 01:29 AM

Pommy,

Thanks for using my formulas. I haven't looked at them in a long time and I hope I got them right :)

The math is not all that complicated, but there's a lot to keep track of. As you may have noticed, I like working in metric units with Plato. This makes calculating the amount of sugar a bit easier. It's easy enough to convert from metric back to US units.

Apparently I did not get the formulae completely right.

I found an issue with the formula for AA (apparent attenuation) it should be

AA = 100 - 100 * FE/OE = 100*(OE-FE)/OE

It seems that you already corrected that.

I found another problem: In E9 you actually want to use the specific gravity (sg) of the wort and the original extract (OE) in Plato. You also need to divide by 100 to get the extract content in g. The specific gravity is needed to convert the wort volume into wort weight. I clarified this a bit in my article by referring to lower case sg. This will get you closer to the 240g extract that should be in the 2 L. Plato is the % extract in a given wort. I.e if you have 2l, which is approximately 2000g, then 12% of that is 240g.

I think that should be it.

Kai

 Pommy 09-29-2012 10:54 PM

Thanks for the input Kai, always great to have a read through some of your work. Does anyone have a calculation for approximate co2 remaining in a fermented wort based on temperature? It doesn't need to be exact as there are too many variables, a simlified equation would be perfect. As long as I get reasonably accurate and more importantly consistent results from the spreadsheet I will be very happy. I'm thinking that I will probably change my whole priming method to using speise if it works well.

:mug:

All times are GMT. The time now is 01:30 AM.