newbie here with 1/2 batch & kegging questions

[douglasbarbin]

I might try this. I'm going to the local home brew store to get the ingredients, but I'm thinking about this kegging system for the 2.5 gallon setup:

http://www.homebrewing.org/25-Gallo...ll-Lock-Keg-Rubber-HandleBottom-1_p_2890.html

Additionally, the instructions on the two brews I have had have had me brew 2.5 - 3 gallons of wort and then top it off to the 5 gallon mark with water to fill my fermenting bucket. Is there any issue with just fermenting the wort without the 2 - 2.5 gallon top off?

Are you talking about brewing the same recipe, but without diluting it in the fermenter?

 

[jpakstis]

Are you talking about brewing the same recipe, but without diluting it in the fermenter?

Yeah. It seems like its not a good move but I was wondering why specifically.

 

[douglasbarbin]

Yeah. It seems like its not a good move but I was wondering why specifically.

For one, your gravity will be much higher than expected. And you will end up with a totally different beer than the recipe.

Also, you probably don't want that much headspace in the primary fermenter. Oxygen and all that...

 

[jpakstis]

Just to follow up, I went to my LHBS and created an all grain/BIAB setup based on what I'm looking for (a citrus/grapefruit IPA, 2.5g). This is what we came up with for ingredients:

5# US 2 row
8oz carared
8oz carapils
5ml hop resin (60 min)
1oz amarillo (10 min)
1/4 tsp irish moss (10 min)
1oz citra (5 min)
1oz amarillo (flameout)
Safale US-05

On brew day, I got 2g of water to strike temp (172 degrees), then mashed for 60 minutes (this was my first time mashing, and I was able to keep it between 154-157 temp in an oven that was primed but off). Did the iodine test and it came up fine. Then boiled with above additions. Chilled to 75 degrees, pitched rehydrated yeast and now its happily fermenting away. It was down to 1.75g so I topped it up to 2.5g. I used a refractometer for the first time and got a Brix reading of 15 (1.061 OG), but I think that might have been because I forgot to take a sample until I had poured just about all of the wort into the fermenter so I took a sample from the bottom of the pot.

Incidentally, and this is probably a "duh" comment, but wow, wort chillers are amazing! On my first brew, I thought I'd chill by nestling the pot into the snow, and it took forever (close to 3 hours) to chill because the snow ended up insulating the pot. Luckily it didn't get any infections. My second time, I used an ice bath, and it took about 40 minutes. This time it was about 10 minutes.

 

[Adub71]

they have equipment that will allow to use your CO2 tank to force the fermented beer from your racking bucket into the keg. Since it fills from the bottom of the liquid dip tube, you can vent the keg prefilled with CO2 as the beer flows in. No O2 = happy beer drinker!

 

[Adub71]

Dude, 21% O2 will to some degree degrade the beer thru oxidation in the keg. For a strong dark beer, you probably wouldn't notice. For a delicate pilsner, it will turn it to raccoon piss.

That's why they cell citric acid powder for when filling bottles - it reacts with the O2 somehow to render it inactive.

 

[Adub71]

Since you say you nurse your beer, you can have the best of both worlds, by bottling and kegging a 5 gal. batch. I would use 5 gal. kegs (pinlock kegs are about 2 in. shorter than ball lock kegs), and keg half the batch (about 1 case). That will leave the other half of the batch to bottle (about a 2nd case). Tap the keg first, and when that is empty, then you can drain the bottles. Unless you are making Weiss or Hefeweiss, the beer in the bottles should last 3-9 months (or longer, depdending on how strong it is).

The advantage of the 2.5 or 3 gal. kegs is that you can fit more of them in a traditional kitchen fridge, which means you can have more styles on tap at once. But, you will find that used kegs, whether 2.5, 3 or 5 gallons, all cost the same. So just stick with 5 gal. corney kegs. You can purge the headspace with CO2, as you can see on this discussion.

Cheers!

 

[Adub71]

[*]Do NOT remove the lid, as that would allow air back in and mix quickly. Instead, when ready to rack, remove the gas post and dip tube and snake a 3-4' long 1/4" OD tubing down the threaded stub, it just fits.

[*]Open the PRV valve! You need to vent the CO2.


[*] There cannot be much air gotten into the keg during this process.
[/LIST]

After filling the keg with CO2, once you remove the gas post/dip tube, all your CO2 will escape (it's under pressure and wants to get out), and it will immediately be replaced by air. Other than wasting CO2, you could put out a small fire with the escaping CO2, that's about all it's good for. Sorry man.

 

[AnOldUR]

 

[doug293cz]

After filling the keg with CO2, once you remove the gas post/dip tube, all your CO2 will escape (it's under pressure and wants to get out), and it will immediately be replaced by air. Other than wasting CO2, you could put out a small fire with the escaping CO2, that's about all it's good for. Sorry man.

Removing the post & tube will reduce the CO2 pressure in the keg to atmospheric pressure. However, the CO2 will not be immediately replaced by air. It will take significant time for air to diffuse into, and the CO2 to diffuse out of, the keg thru the small opening. A small amount of air will get into the keg while it is being filled, but this can be removed by a few purge/fill cycles.

Brew on

 

[Adub71]

Hmmm, I guess it would be logarithmic, with a lot of CO2 coming out fast at first, then slowing towards the end. I would hate to test it with an entire keg full of beer, but I guess that is the only way...maybe I could make a 3.25% beer to test it.

 

[IslandLizard]

After filling the keg with CO2, once you remove the gas post/dip tube, all your CO2 will escape (it's under pressure and wants to get out), and it will immediately be replaced by air. Other than wasting CO2, you could put out a small fire with the escaping CO2, that's about all it's good for. Sorry man.

First, if you read my post closely, there is no over-pressure of CO2 when pre-purging the keg, as the Starsan is being pushed out and replaced with CO2.

Then when removing the gas post and short diptube the small opening of the stub will not allow air to infiltrate quickly. Before inserting the skinny tube, you could pre-purge it with CO2 or insert it while streaming CO2 through it slowly. The inside volume of that tube is very small though, and quite insignificant on scale of things here.

Removing the post & tube will reduce the CO2 pressure in the keg to atmospheric pressure. However, the CO2 will not be immediately replaced by air. It will take significant time for air to diffuse into, and the CO2 to diffuse out of, the keg thru the small opening. A small amount of air will get into the keg while it is being filled, but this can be removed by a few purge/fill cycles.

Brew on

Why would (a small amount of) air make it into the keg while filling? CO2 is being pushed out while being replaced by an equal volume of beer.

As illustrated above, purging of half filled kegs has very diminishing returns for the amount of CO2 needed. I think we'd concluded that a keg that's even 80% filled (20% headspace, 100% filled with air) needs around 5 gallons of CO2 to be purged to a residual O2 level of 2% (~10% of air).

 

[doug293cz]

Why would (a small amount of) air make it into the keg while filling? CO2 is being pushed out while being replaced by an equal volume of beer.

Some air will get in before the tube is inserted, and unless the tube is a tight fit, some air will diffuse thru the gap between the tube and post hole. But, this is a mostly academic discussion. In any case, your method of keg filling will allow much less air into a keg than just sticking a tube in with the lid removed. My response was more aimed at the poster who said air would rush into the post hole and displace all the CO2.

Brew on

 

[IslandLizard]

Some air will get in before the tube is inserted, and unless the tube is a tight fit, some air will diffuse thru the gap between the tube and post hole. But, this is a mostly academic discussion. In any case, your method of keg filling will allow much less air into a keg than just sticking a tube in with the lid removed. My response was more aimed at the poster who said air would rush into the post hole and displace all the CO2.

Brew on

Yeah, I know you were directing it at the other poster, just wondered where you thought a lot of air could get in. That 1/4" OD (1/8" ID) tubing is a pretty good fit for that keg's stub.

The key is to avoid sucking air in through the racking tube (or auto siphon). You need to pinch it at the right moment before getting greedy to get all the beer out of the fermentor. Besides, you need some beer left behind to swirl up and harvest the yeast cake. I tip the bucket when the beer level gets low, say below 4 inches, then start to tilt.

 

[doug293cz]

Yeah, I know you were directing it at the other poster, just wondered where you thought a lot of air could get in. That 1/4" OD (1/8" ID) tubing is a pretty good fit for that keg's stub.

The key is to avoid sucking air in through the racking tube (or auto siphon). You need to pinch it at the right moment before getting greedy to get all the beer out of the fermentor. Besides, you need some beer left behind to swirl up and harvest the yeast cake. I tip the bucket when the beer level gets low, say below 4 inches, than start to tilt.

I said "a small amount of air." That's rather different than "a lot of air."

You don't really have to worry about shutting off the fill flow to avoid getting air into the keg when the fermenter is going dry. Since the end of the tube is submerged during fill, no air will get below the fill line in the keg (as long as you're not sucking a lot of air bubbles with the beer flow.) When the fermenter is empty (or keg is full) just shut off the valve (or pinch tube), disconnect the tube from the fermenter, siphon, or whatever, and carefully withdraw the tube from the keg. The only air introduced will be the the volume displaced by the tube in the headspace. Then replace the keg post and purge (as many times as it takes to make you happy. Refer to my purge table in an earlier post.)

Brew on