Priming sugar question

[Toto's]

I was bottling some pislner this morning. For the first time i was able to lager a beer at 1C degree for 5 weeks thanks to my new temperature controller.
Now when i punch in the data...
18 liters but my temperature....
I am aiming a carbonation around 3.0 ... but now if i put my actual temperature of my beer 6 degrees
Well i have to put 116.5 gr of white sugar. If my beer temperature is 18 degrees i need 150gr of sugar.
I have some problem understanding the logic behind this.
How can i get the same carbonation at
6 degrees with 116.5 gr. Of sugar and at 18 degrees with 150 gr. Os sugar?
Wouldn't the sugar be consumed anyway by the yeast but at lower temperature it would take more time? Please enlighten me

I finally set for 18L. At 18 degrees for 135 gr. of sugar and did a temperature reading just before capping the bottles and i got a reading of 16 degrees so not that bad

 

[Tobor_8thMan]

I believe you've discovered it takes less CO2 to carbonate a cold brew vs a warmer brew. This is why 6C needs 116.5 gr vs 18C needs 150 gr.

 

[VikeMan]

How can i get the same carbonation at
6 degrees with 116.5 gr. Of sugar and at 18 degrees with 150 gr. Os sugar?
Wouldn't the sugar be consumed anyway by the yeast but at lower temperature it would take more time? Please enlighten me

In the calculator, you want to use the temperature the beer was at the end of active fermentation. When you subsequently lagered (in a sealed vessel) at the lower temperatures, there was no more CO2 being produced. The reason the calculator asks you for the temperature is so that it can estimate how much residual CO2 from fermentation is left in the beer, as the starting point. After that, any given weight of sugar will make the same amount of additional CO2 regardless of the temperature at which the yeast consume it (assuming it's warm enough for the yeast to be active).

 

[Toto's]

I usually leave the bottles in a room at 19 degrees for carbonation....
That beer max temperature has been 13.5 .....
Am i going to have a overcarbonation problem
Well i just punched in 13.5 degrees... for 18L at 3 CO volume.... 140gr...
I guess i have been very lucky, i put 135gr.

 

[VikeMan]

I usually leave the bottles in a room at 19 degrees for carbonation....
That beer max temperature has been 13.5 .....
Am i going to have a overcarbonation problem

If you computed sugar based on residual CO2 at 19C, but the temperature was only 13.5C at the end of fermentation, then yes, you'll over carbonate slightly. By roughly 0.15 volumes.

But if you haven't already primed, just compute using 13.5C.

 

[Toto's]

Well it's been more than 2 years that i brew and i thought i know how to prime i beer. I had to wait until my first real lager beer with a temperature controler to really know how to prime properly a beer. Thanks guys for the quick answers . Today i am a better brewer than yesterday lol