I don't see this mentioned often. But conceptually it seems difficult for me to believe you can use some universal calculator. Wouldn't the structure of the beer, and the type of yeast used be a big factor? Don't yeasts all work at different rates and different potentials? Also what kind of bottles are you using and how full are they? Etc... Maybe it's simpler than I think but a "calculator" is a bit of a misnomer ; not a precision tool but an estimator. That being said I've used the N. Brewer tool, I think best thing is to use it or some other calculator a couple times, and adjust accordingly to taste.
Priming calculators wrong?
- Thread starter mrchicken
- Start date
Help Support Homebrew Talk:
Not really any dependency on beer type or yeast, at least if you prime with simple sugars (corn sugar [dextrose monohydrate] or table sugar [sucrose].) All yeasts will completely consume these simple sugars, and turn them into alcohol and CO2. The beer type and yeast will affect how long it takes to completely carbonate, but priming calculators aren't intended to make any prediction of time required.
The most important factor for achieving consistent carbonation levels is to make sure your beer is completely fermented prior to bottling. If you have a different amount of residual fermentables batch to batch, your carb levels will be all over the map. Use the "stable FG for three days" criterion to determine when fermentation is complete.
Bottle type will only affect the outcome if you use a bottle style that gives you a significantly different headspace to beer volume ratio (as noted by jwalts.) But if you use a bottling wand to fill to the rim, then the headspace volume will consistently be the displaced volume of the wand in the bottle. For "normal" bottle shapes, the displaced volume will not vary much from style to style. Typical headspace volume is about 6% of the beer volume. I doubt variations from 4% to 8% would change carbonation level enough to be detectable in blind testing. If you are really interested, I can calculate the difference in CO2 volumes for a range of reasonable headspace ratios.
Your best advice is in your last sentence: i.e. consistently use the same calculator, and learn the "fudge factor" to apply to get results that you like. Using multiple calculators at different times will make getting consistent results more difficult.
Brew on
Orerockon
Active Member
IMO They are conservative, I guess they don't want people blaming them for bombs. I saw recommended oz. all over the map and used 1/3 to 1/2 c. for a few batches of cider that were decidedly wimpy. Then I got ticked off and upped it to 1 c. which was perfect. Now that's what I use for every batch of cider and several variants of mead with several different yeast strains. I've had about 5 champagne bottles out of probably 1000, no bombs. I really don't think it matters what recipe as much as how much sugar your priming yeast consumes. I always go with the same yeast I used to ferment.
Silver_Is_Money
Larry Sayre, Developer of 'Mash Made Easy'
I just did a quick (and by no means fully extensive) comparison of the Northern Brewer priming calculator and the Brewer's Friend priming calculator, and from my brief observation it appears that Brewer's Friend calls for roughly 9% higher priming sugar quantities than does Northern Brewer. If Northern Brewer is an example of conservative, then by that measure Brewer's Friend does not appear to be conservative.
I assume you specified the same sugar in both cases, yes? Did you specify dextrose (corn sugar) or sucrose (cane/beet sugar)? Most dextrose is actually dextrose monohydrate, so it requires ~10% more dextrose monohydtrate than pure dextrose to carbonate to the same level. Might Northern's calculator be calculating based on pure dextrose?
The more probable cause for the difference is that Northern's calculator is assuming higher levels of residual CO2 in the beer post fermentation, so calling for less sugar to get a specific number of volumes.
Brew on
Silver_Is_Money
Larry Sayre, Developer of 'Mash Made Easy'
I assume you specified the same sugar in both cases, yes? Did you specify dextrose (corn sugar) or sucrose (cane/beet sugar)? Most dextrose is actually dextrose monohydrate, so it requires ~10% more dextrose monohydtrate than pure dextrose to carbonate to the same level. Might Northern's calculator be calculating based on pure dextrose?
The more probable cause for the difference is that Northern's calculator is assuming higher levels of residual CO2 in the beer post fermentation, so calling for less sugar to get a specific number of volumes.
Brew on
In assessing the 9% difference I looked in all cases at both corn sugar and granulated white table sugar, and I strictly compared apples to apples and oranges to oranges. I have no idea what these programs look like internally. Just as for you, I can only use them, I can't dissect them. Brewer's Friend shows us its estimate of the volumes of CO2 present before priming, but Northern Brewer does not, so a comparison on this basis is not possible.
Similar threads
