Priming with unfermented wort?

[Cononthebarber]

So it came to me in a dream...if you made a brew and saved some of your wort and kept it in say a DJ and didn't allow it to ferment, could you then use that when bottling, to prime your beer?

A "self-priming" beer?

If it is possible how much do you think you'd need in each bottle to get good carbonation?

 

[alanywiseman.]

Is this not how beers brewed by the German Purity Laws are brewed?

In my head it is completely possible but you would need to run a test brew using the same yeast and wort to know your OG and FG. From this you can calculate the germs table sugars present and so the volume you would need to prime your brew. However for this I would think that batch priming would be a lot easier.

 

[daveozzz]

I think your answer is in here if you can decipher it: http://braukaiser.com/wiki/index.php?title=Kraeusening
The spreadsheet looks simple enough (the link is after all the hard sums).

 

[Cononthebarber]

Wowzer! Thats a complicated equation! I think i'll just stick to sugar or DME at the minute for priming...although I'm glad it is possible :)

 

[daveozzz]

Not attempted to understand the maths but plugging some figures into the spreadsheet seemed doable..
According to it, if you keep a sample of 1.060 wort which then goes on to ferment to 1.012, you would need 2L to prime 23L to 2.8 volumes....
If it only goes to 1.015 you'd need 2.2L to do the same etc...