# Bulk Priming How Much Dextrose Per Liter?



## Outback Brewshed (27/3/05)

Hi I have a 23L batch of Lager. 

Now rather than keg the whole lot I'd like to Keg 18 L of it and carbonate with CO2 from a gas bottle. Nothing out of the ordinary there.

But with the remaining 5 L I wish to bulk prime it in a racking fermentor and bottle it in 700ml Bottles.

My Question is .... How much dextrose per liter do I put in the racking fermentor.

To achieve the following levels.

a. Low Carbonation,
b. Medium or Normal Carbonation, or
c. High carbonation.

Ok Im trying to be as clear as possible with this question. 

Your help is very much apprecited.

Thanks,

OB


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## sosman (27/3/05)

There is quite a bit out there on google which can help. Search on
dextrose carbonation beer

eg http://www.unm.edu/~draper/priming.html

I tend to use up to 10g/litre but I mostly keg.

cheers


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## Steve Lacey (27/3/05)

Outback Brewshed said:


> a. Low Carbonation,
> b. Medium or Normal Carbonation, or
> c. High carbonation.
> 
> [post="51098"][/post]​



a. 0-3 g/L
b. 4-6 g/L
c. 7-10 g/L

If you want to read up on everything you wanted to know on bulk priming, and probably stuff you didn't, I co-wrote an article a year or two back. It's in parts. Here is the introduction

You probably just want to skip to ths page with the essential details.

Steve


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## Outback Brewshed (27/3/05)

Thanks guys, this info is exactly what I needed. 

Dane can we please AIRLOCK this thread for future reference?

Thanks again,

OB


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## SJW (27/3/05)

And it almost, but not quite, goes without saying that the amount of time that the beer will be kept before drinking will play a large part in how much Dex. to use. If i make a Bock that is going to be drunk after a min of 2 or 3 weeks, and before about 16 weeks i would use a lot more than the same beer that i was going to store up, for my normal time, of about 12 weeks before starting to drink. (if u can understand that)


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## rodderz (27/3/05)

sosman said:


> There is quite a bit out there on google which can help. Search on
> dextrose carbonation beer
> 
> eg http://www.unm.edu/~draper/priming.html
> ...



Great link there mate, been trying to figure out how much priming my stout will need as its just about bottle time!


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## BJCP Education Director (28/3/05)

That is a good link. Here is an easy way to calculate:

4g/L of Corn Sugar = 1 vol CO2

I always assume that I have 1 vol of CO2 left in the wort after fermentation. Which is about right from all the CO2 bubbling through.

Outback,

for your example you will want about 2.5 vol of CO2.

1 vol is still in solution.

So you need 1.5 vol of CO2 from sugar

4g/L x 1.5 vol = 6g/L for 1.5vol

6g/L x 23L = 138g 

Cheers


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## Guest Lurker (28/3/05)

Hi BED

Down here we dont use the term corn sugar and it can cause a lot of confusion if you do. By corn sugar what I think you mean is what we call dextrose.

The problem is that maltodextrin in Australia is sold as dried corn syrup, or dcs, and is commonly used in "booster" packs to add body to kit beers. The fermetability of dcs varies but the stuff usually supplied is about 30%. 

So if you recommend to a new brewer that they prime with corn sugar, they will toddle off to the brew shop and come back with DCS.


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## SJW (28/3/05)

STEVE L got it spot on. It does not get much closer to the mark than this. And i would say this is nice and conservative for long bottle conditioning.

a. 0-3 g/L
b. 4-6 g/L
c. 7-10 g/L


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## Steve Lacey (28/3/05)

SJW said:


> And it almost, but not quite, goes without saying that the amount of time that the beer will be kept before drinking will play a large part in how much Dex. to use.
> [post="51124"][/post]​



Good point...and in addition to the storage duration, you do need to take into account the amount of dextrins in the wort. The higher a beer's finishing gravity, the greater will be it's tendency to gradually increase it's carbonation level over time. Although we call those dextrins "unfermentable", the yeast do seem to nibble away on them. For most regular gravity beers (up to 1060 OG), I don't find that this makes a very big difference, but with something like a triple that finishes at 1018 or so, I find deciding the right priming level a real head scratcher because a lot of the necessary assumptions are overwhelmed by the unknowable residual fermentability question. You know you want high carbonation, and there is a chance that you will get that eventually even if you add _no_ priming sugar at all. So how much do you add?

I'd be interested to hear some experiences on how people handle the bottle priming for their big beers like Belgians, barley wines and the like. My gut feeling is a lot of people will say they don't add anything except plenty of time.

Steve


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## BJCP Education Director (28/3/05)

Apologize for the confusion. Yes here we interchange names of corn sugar and dextrose.

Dextrose is what I am talking about.

Thanks for letting me know


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## sosman (28/3/05)

BJCP Education Director said:


> Thanks for letting me know
> [post="51194"][/post]​


I thought that was what your title meant, we educate you directly.


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## BeerIsGood (14/7/05)

I have written a priming sugar calculator to help with bulk priming. I would appreciate any feedback to make it more accurate or useful.

*To use, rename attached ".txt" file to ".exe".*

It calculates bulk priming rate of dextrose in g/L based on desired carbonation and pre-priming temperature, and calculates out total grams for your brew.

Calculations are based on the following assumptions:

(1) The brew has a saturation of CO2 before priming for it's present temperature, just before priming (eg: fermentation, secondary, cold conditioning, lagering).
(2) The saturation of CO2, in "Volumes of CO2" is calculated, as a function of temperature (T), in degrees Celsius, as follows: Volumes CO2 = 0.000849 x T^2 - 0.058751 x T + 1.7114
(3) The rest of the CO2 in your beer is dictated by the rate of dextrose added per litre, such that 1 Volume of CO2 will be produced by every 3.7 g/L of dextrose added.

Negative dextrose rates means that your desired carbonation is less than the saturated level of CO2 for beer at that temperature.

I hope that this tool is useful to others, and not just myself. Let me know if there are any problems, suggestions, etc.

_Edit 18/07/05 - Removed attachment. The packaging of the file has been updated (see posts below), but how the calculator works, as described above, is still valid. Have another beer._


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## sintax69 (15/7/05)

BeerIsGood said:


> I have written a priming sugar calculator to help with bulk priming. I would appreciate any feedback to make it more accurate or useful.
> 
> *To use, rename attached ".txt" file to ".exe".*
> 
> ...





Get cvirte.dll not found error??? any idear google it and it referres to labview ????


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## BeerIsGood (15/7/05)

Sorry, my fault.  
I developed this in LabWindows/CVI (similar to LabVIEW), and didn't compile it to include the dll's required to make it run a computer that doesn't have LabWindows installed. I'll recompile it soon, then *test* it at home, and repost.
Sorry about that.


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## Doc (18/7/05)

This is from BeerIsGood who was having trouble with the attachment.

Beers,
Doc

Please download the attached zip file and open "readme.txt" for installation details.
View attachment BeerIsGood_Priming_Calculator.zip

Installation is quick & painless (


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## Joel (18/7/05)

Downloaded and installed without any problems. 

Fired the program up and had a bit of a fiddle... Looks good.


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## peas_and_corn (18/9/05)

Yay! seems pretty good to me...


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## Stoodoo (10/1/06)

AARRRGGGHHH, this calculator is what I've been missing for so long now. Must give it a try and see how my beer works out after a few months.

Cheers


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## tangent (10/1/06)

don't forget there's always basic online calcs
http://www.tastybrew.com/calculators/priming.html
for example


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## ryanator (11/1/06)

If you are using honey in a brew, you must take into consideration that honey takes a very long time to finish fermenting. I bottled a brew about 4 months ago which had honey in it and primed it with 6 grams of dextrose per litre. The beer has gradually become fizzier and fizzier to the point where I have had to chuck the lot into the fridge and drink them real quick before they explode.


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## dogbolter (8/10/06)

Thanks BeerIsGood for the calculator. 

Much appreciated.


Dogbolter.


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