Correct PSI and tube length for Schneider Weiss

[saigon]

I'm having problems dispensing a 50 l. keg of Schneider Weiss in my kegerator. With help from Micro Matic, I was able to procure a Type "M" coupler for this beer and thought I was off and running. The rep at the beer's importer (B United International) said Schneier Weiss has a native pressue of 29 psi @ 40 deg. F.(yeah, pretty high). Now, I'm a big fan of German wheat beers (have the setup for Hacker-Pschorr etc.) but this high of a psi is posing some problems of which I did not experience with the other German beers. I purchased new beer tubing for a 10 foot run thinking pressure would drop 2.5 psi per foot and the fact that my fridge temp of 38 F. is lower than the quoted spec 40 F.( usin Johnson Controls external probe). Regulator shows 29 psi but beer is complete foam even after an extended draw (5 1 liter glasses with no stopping). Please help draft gurus and forgive the excessive parenthesis.

[Scott Zuhse]

Wow! That is alot of gas in the beer. Keep bumping up the pressure until you do not see any bubbles rising just above the coupler. Quickly open and close faucet before you look for bubbles (use flashlight). We had this similar issue in a workshop with a highly carbed beer and ended up with about 30 PSIG with lots of 3/16".

Alternative would be to shake down the carbonation. Why does this beer need so much in the first palce. Is there that much second fermentation going on?

Scott Zuhse, Instructor Micro Matic Dispense Institute

[saigon]

Not sure why the carbonation needs to be so high. Thought about bleeding it down but want to preserve the beer as close to possible in it's maker's intended state. I currently do not have bubbles rising above the coupler after faucet use with regulator showing 29-30 psi @ 38 F. In this time since I first posted, I noticed that the serving temp range suggested for best flavor is 48-54 F. But this would increase co2 even more (by 1 psi per every 2deg. if I remember correctly). I would like to approach the suggested serving temp, but need to get the co2 problem worked out. Is it true that where the faucet meets beer glass, the psi should be very close to zero? Then am I adding more 3/16"?

[saigon]

Ok, here is the response the beer's importer just gave:

David,

Please pour it at between 40-42 F: If you pour at 46-48F the pressure you
need to apply gets very very high -> You will then incur the risk of
overcarbonating Schneider Weisse.

1. The PSI at the keg is subject to the temperature of the liquid. At 40-41F
the equilibrium PSI pressure required is about 28-29 PSI. For each ft. of
line/rise of line you need to add PSI {to overcome the resistance}.

2. If you use a flow restrictor {= to be attached to the faucet/a tool to
manage the flow of the liquid} the PSI at the faucet should match the
equilibrium pressure of 28-29PSI. In order for you to avoid the liquid
shooting out of the faucet into the glass {28/29 PSI is quite a pressure!}
you will "dial down" the speed of the flow through the flow restrictor

3. If you don't have a flow restrictor {cost = US$ 65.00} then you need to
add "choker" line in front of the faucet to slow down the liquid. If you
don't do that then the liquid will be clear in the line - however, as soon
as it the glass {via the high speed} the C02 will break out turning
Schneider Weisse into a "foaming mess"

4. Lastly , if you use 100% CO2 gas then the keg needs to be emptied in no
longer than 5-7 days - otherwise the continuous pressure of the CO2 upon the
beer will cause the beer to get overcarbonized {ie the C02 will "go into the
liquid" and raise the natural level of C02 dissolved in the liquid}.

Our recommendation is a mixed gas, 30% nitrogen, 70% C02. If you use 100%
nitrogen then you will cause the beer to go flat within days.

Best regards

[Auld Og]

Thanks for posting this, this is really valuable informaton to me. I could see myself getting a Schneider keg down the line (no pun intended). Acutally there's a bunch of things I'll probably get from B United, the new Harviestoun B&T when it comes out springs to mind. Anyhow I recently put on my first beer that required what I consider higher than normal pressure (Brooklyn Pilsner). I set it for the brewer's recommended psi (18 IIRC) but it seems a bit more "sprightly" than it should be. I'm assuming that the psi figure is for a longer beer run than I have in my kegerator.

[Auld Og]

"Our recommendation is a mixed gas, 30% nitrogen, 70% C02. If you use 100% nitrogen then you will cause the beer to go flat within days."

Where the hell do you get that combo gas? "Guinness" gas is the other way round 70/30 or 75/25 (N2/CO2). The folks at one of my locals have had Schnieder on and I don't remember a flow restrictor type faucet. I'll ask them and see what they did to get the beer to pour.

[saigon]

Thanks Old Og for checking with your "locals" as to how they dispense Schnieder. Unfortunately, In Pittsburgh, few have ever heard of this beer and nobody has it on draft, so I can't very well enlist my "locals" in this quest. I'll be checking back frequently to see what you find.

Cheers to all working on this.

[Scott Zuhse]

A Gas Blender is the best method of providing the correct blend for the SW. I would follow this recommendation first:

The PSI at the keg is subject to the temperature of the liquid. At 40-41F the equilibrium PSI pressure required is about 28-29 PSI.

Forget about the changing of pressure for restiction. Otherwise you will loose equilibrium. I could never understand why you would change 100% CO2 pressure when it should always be based on temperaure to gain equilibrium. Start with about 12' of 3/16" ID vinyl and trim back in six inch increments until you obtain the desired flow rate.


Scott Zuhse, Instructor Micro Matic Dispense Institute

[saigon]

The gas blender is a bit pricy @ $545.00. I've opted to go with the John Guest Flow Restrictor from Micro-Matic for under $30.00. It should be here in a few days, will let you know how it works out. Thought about a Guiness or stout type faucet (with restrictor plate removed) as they have built-in, dial type flow restrictors but will wait and see how this other solution works first.

[N928J]

My Schneider keg is on order, anyone have the outcome to the CO2/Nitrogen mix/pressure/flow restrictor situation?

[draught guy]

Schneider weiss and Adventinus(same brewer) When I hookem up usually 30' and 10' additional 3/16 Schneider is darn good beer unfortunatly it isnt as good in the bottle something about bottle fermantation perhaps.you can also purchase restrictors small mesh screens you insert in the hole in the shank (take off faucet and the hole you see is the one I am talking about) determine if the hole is 3/16 or 1/4 the restrictors come in both sizes you can vary the restriction by how deep you insert the screen.The european type faucet with restriction adjust knob is a little pricey and will not seat properly in most standard shanks outhe end of the piston is conicall and you would need a deep shank to accomidate it.You can purchasr beer gas wich is a premixed blend depending how quickly you go through a keg this could cause taste issues at the end of the keg.

[brian92]

A couple of quick points here since I have done the research on german hefes and have dispensed Erdinger and Schneider Weiss in my kegerator successfully.

In general, it's not that difficult once you accept the fact that the beer was intended to have an extremely high CO2 content level. This was designed by the brew master. Your looking at around 6.8 grams/liter as a max CO2 level. I forget my conversions from g/l to vol of CO2 (I actually did all the calcs at one point), but it's in the neighborhood of 3.2 - 3.3 vol CO2. Yeah, that high.

So, if you go straight CO2, at 38 degrees, you're looking at a pressure of ~ 19 PSI. It is also true that if you go that high with 100% CO2, the beer will overcarbonate in about a week or so. I go with a 60% CO2 and 40%N blend. If you go with a blend, you will need to increase your pressure significantly to balance the co2 content or the beer will eventually go flat. You can find more information from McDantim's website (http://www.mcdantim.com/brochures.htm). With a blend and the right PSI, my german hefe kegs last about 1-1.5 months. I can't say enough about the folks at McDantim. They know their stuff and the website is extremely helpful.

So, where does that leave you for line length? It's 2.2 lbs/ft of restriction for 3/16" vinyl tubing at a flow rate of 128oz/min (industry standard). Therefore, at 19 PSI, you're looking at 8.6 feet. I typically go with a slightly longer run to slow the pour rate down a bit.

If you go by those general principles, you will have no problem dispensing a german hefe.