Bulk priming a keg?

[Truman42]

Morning gents,

I'm wanting to bulk prime my 9 litre keg because...

-I don't have enough bottles.
- I don't have room in my kegerator for another keg.

Is it the same deal as when you bulk prime bottles?
Transfer to my bottling bucket with priming solution tipped in then drain 9 litres to the keg and the rest into bottles? Then store keg with bottles for 2-4 weeks?

The reason I ask is that I think I may have read on here that the amount of priming solution is different when you naturally carb a keg. I could be wrong and to be honest logic tells me it's just a big bottle but wanted to clarify before I stuff it up.

Thanks heaps.

 

[Black Devil Dog]

You only require half the amount of priming sugar to bulk prime kegs compared to the amount for bottles.

According to Beersmith, a 9 litre keg stored at 25deg, carbonated to 2.3 vols co2, requires roughly 28 grams of dextrose..

The same qty to bulk prime bottles would require about 56g.

 

[DU99]

about 25 grams of dextrose

 

[Truman42]

Ok so I should pour 28 grams of dextrose into my keg, drain off the beer into that then transfer the rest to my priming bucket with the required solution?

EDIT: When you say storage temp is that the temp Im going to store the keg at or the highest temp reached during fermentation, as it is when you prime bottles?

 

[DU99]

boiled water and dissolve, like a cup tea then add to keg works for me.

 

[Black Devil Dog]

What I do is dissolve the dex in a sanitised jug, with just enough boiling hot water to dissolve it, then pour that into my keg and then transfer the beer.

I've never kegged half a batch and bottled the other half, but what you suggest makes sense.

I used 25 deg as storage temp because that's my unreliable, scientific summer time average of what the temp is under my stairs, yours will no doubt be different and cooler temps are better if it is possible to do it.


Edit. Just re-read your question. My take on the temperature thing for priming, is the storage temp after priming, not highest temp duing fermentation. But if I had the capability of doing so I would try and keep the storage temperature as close as possible to fermentation temperature.

 

[Truman42]

Ok cheers for that. Just wasnt sure because I know when you bottle you have to use the highest temp reached during fermentation as that will determine how much CO2 will be left in the beer at bottling time.

And when I said throw dex into the keg, I meant dissolve in hot water first which is what I always do.

Thanks again

 

[squirt in the turns]

Ok cheers for that. Just wasnt sure because I know when you bottle you have to use the highest temp reached during fermentation as that will determine how much CO2 will be left in the beer at bottling time.

This was my understanding - not, as BDD suggests, the secondary fermentation temperature. Technically I think it refers to the max. temp the batch has reached after the majority of fermentation has finished, as the amount of CO2 produced by fermentation that stays in solution at atmospheric pressure is determined by this temperature.

Happy to be corrected. Haven't had to think about this for a while actually as it's been years since I did anything other than force carb.

 

[Screwtop]

It's easy using an adjustable pressure relief valve Truman. Cheap from gas places think mine cost $18. After priming with whatever (sugar, dex, malt extract, wort) hook up a line from the gas post of your keg with the relief valve (use your gas bottle to set relief pressure) set at 110Kpa with line out into a bottle of water beside the keg. Leave at room/shed temp until the bubbles stop, no risk of using too much, can't over carb the beer will be carbonated to the set pressure.
Have a search for the Speise method of naturally carbonating a keg, keeps you within the Reinheitsgebot if you're into that stuff.


Cheers,

Screwy

 

[Black Devil Dog]

Beersmith has a carbonation tool which has an option to adjust the storage temperature, it then compensates for that and gives you an amount of sugar/dex to add depending on your desired co2 vol.

 

[squirt in the turns]

Beersmith has a carbonation tool which has an option to adjust the storage temperature, it then compensates for that and gives you an amount of sugar/dex to add depending on your desired co2 vol.

I reckon the way Beersmith presents these fields in the Carbonation Tool and also the associated info on their website is a bit misleading. It asks for the "Temperature of beer when bottling or storing", which is fine if that temperature is the same as the fermentation temperature. But if the temperature has at any point risen since the yeast stopped producing CO2, then that (higher) temperature is what I believe should be used. Therefore, I don't think it refers to the intended storage temperature, but the current temperature, and makes the assumption the temperature has never been higher.

For example, if I tell it that I have a 19L keg of beer at 1 degree and want 2.4 vols of CO2, it tells me to use 28.64 grams of dex. If I hold that keg at 1 degree, that sugar will never ferment and my beer will stay flat. The tool also fails to acknowledge that a beer would not ferment at 1 degree and therefore it is impossible for that to have been the maximum temperature, but it calculates residual volumes of CO2 as it it were.

The instructions for the bottle priming calculator here agree with my point, while this one acknowledges the many factors at play without offering a definite answer.

 

[Truman42]

I reckon the way Beersmith presents these fields in the Carbonation Tool and also the associated info on their website is a bit misleading. It asks for the "Temperature of beer when bottling or storing", which is fine if that temperature is the same as the fermentation temperature. But if the temperature has at any point risen since the yeast stopped producing CO2, then that (higher) temperature is what I believe should be used. Therefore, I don't think it refers to the intended storage temperature, but the current temperature, and makes the assumption the temperature has never been higher.

For example, if I tell it that I have a 19L keg of beer at 1 degree and want 2.4 vols of CO2, it tells me to use 28.64 grams of dex. If I hold that keg at 1 degree, that sugar will never ferment and my beer will stay flat. The tool also fails to acknowledge that a beer would not ferment at 1 degree and therefore it is impossible for that to have been the maximum temperature, but it calculates residual volumes of CO2 as it it were.

The instructions for the bottle priming calculator here agree with my point, while this one acknowledges the many factors at play without offering a definite answer.

I was going to say the same thing. I think beersmiths wording is wrong and it should say highest fermentation temperature reached. Or as you say it assumes you are storing them at the same temp as fermenting them.
It wont make any difference as too how much carbonation you get if you store at 18C or at 25C it should be the same volume per amount of dextrose you use. Only difference that temperature makes when carbing is how long it takes. A beer carbed with 25 grams of dex stored in winter at 18C will have the same volume of CO2 as a beer carbed with 25 grams of dex stored in summer at 28C. It will just carb up quicker in summer.

If you go on storage temps beersmiths calculator says use more dex in summer than you would in winter.

 

[Ducatiboy stu]

Coopers prime in their kegs at 5g/ltr. The same rate as their bottles with sugar.

Asked Dr Tim about it......he also went on to say that all the other breweries said it wasnt possible...so they did it to show it could be done.

 

[DU99]

i use to get my data from ianh's spreadsheet..