Priming Sugar calculator accurate or not??

[ace0005]

I'm bottling my double chocolate raspberry stout today. I used norther brewer's priming sugar calculator and it says to use 85.53 grams (3.02 oz) of priming corn sugar based on the 4.5 gallons of beer i need to bottle.

I've searched the forums but can't find the answer to this question...Does anyone know if these calculators are accurate??? Please answer asap as I plan on bottling later today.

 

[FightingBob]

All of these online priming calculators are accurate and use pretty similar formulas:


Priming sugar (grams) = 15.195 Vb ( CD - 3.0378 + .050062 * T - .00026555 * T * T );

where Vb is volume of beer in gallons, CD is carbon dioxide concentration in the final brew in volumes, and T is temperature at bottling.

I can't calculate anything without knowing what CO2 volume you're shooting for and the temp of your beer. I will say that these calculators are accurate if you plug in the right data.

 

[Yooper]

I say everyday (or at least it seems like it) that I hate those priming calculators!

There are a couple of reasons. One is the priming 'to style' part. It sounds great in theory, but say you made an English mild. They say "to style" is .75-1.3 volumes of c02. Now that may be true in a pub with a cask ale- but it's really totally flat. Most people who buy commercial bottled beers don't have a bottle at .75 volumes, as that's not true for bottled beers.

The other thing is that while one style may have your beer turn out flat, as above, another style, say a gueuze, suggests priming to 4.5 volumes.

Well, sure, a gueuze is spritzy- but if you bottle carb to 4.5 volumes you will have gushers at the least and more likely even bottle bombs!

The other issue is the "temperature" input. The idea is that the calculator will guestimate how much residual carbonation is in the beer according to temperature. Again, good in theory- but not really a factor at all and it can be confusing for people to use.

I use a pretty standard .75 ounce corn sugar per finished gallon for lower carbed beers, and 1 ounce per finished gallon for others, like lagers, and it works out perfectly. I think sometimes we as homebrewers totally overthink things and make things more complicated than the really are.

 

[FightingBob]

You're probably right about over thinking stuff.

It's still nice (for me) to know the math behind the how and why. If you do the math, you'll see that the OP's priming calc came up with the amount of priming sugar that wouldn't be too stylistically different than your method for lower carbed beers. 3.375 oz for your method verses 3.02 oz for the OP's.

So in the end, as with many things homebrewing, do what works for you and your system.

 

[ace0005]

I've done several brews now, and it seems that everytime I brew I learn something new. I ended up using northern brewers online calculator which directed me to use 85 grams of corn sugar which was a little more than .25 oz. I do like the calculator because like many from my generation (generation x) I suck at math.
The last time I made this brew I used an chocolate stout extract recipe and raspberry and chocolate extract at bottling with 5 oz of priming sugaras directed by my local brew shop. I ended up with bottle bombs and a tasty mess and understand I was given terrible advice! This time I used all grain young 's double chocolate stout clone recipe (my first try at all grain). I added 1.25 lbs raspberry puree in the mash, and 1.25 lbs raspberry puree in the secondary for one week. Beer tastes great at bottling.....but I'm really hoping to avoid bottle bombs. Wish me luck! Sorry for the ramble, but I'm really excited about this beer.

 

[LivingDeadBrewery]

Priming sugar (grams) = 15.195 Vb ( CD - 3.0378 + .050062 * T - .00026555 * T * T );

Hi

if i have understand this correctly this formula is for dextrose ? anyone know how too rewrite it for sucrose?

 

[Talonracer67]

I used a priming calculator for my first 3 AG batches, and I basically have 3 cases of flat beer. I was originally thinking it was too cold then I checked my notes from last year and was getting complete carbonation in two weeks in my low 60 degree basement using the amount of corn sugar you get in those kits. So my advice is to chuck that priming calculator in the garbage and just follow Yooper's advice. If you over-carbonate slightly you just just let the beer sit open for a bit. I do alot of smoking meats so my beer won't go to waste, its good to put in the water pan lol.