Troubleshooting Advice?: Kegging, Mash Efficiency, Flavor

propsout said:

Hi all,

I've been brewing for a few years (~15 extract beers, recently moved to all-grain) and have been having the following problems with my brews over the past 4 or 5 batches (maybe longer but I can't recall):

1) When I put on a new keg in my kegerator, there's always a lot of wasted beer and time getting it to dispense with minimal foam and proper carbonation.
Sometimes, there's an initial huge blast of foam in each pour, but the beer itself is not well-carbonated. So I pour off the foam for a while, and then try to force-carbonate the keg by rolling it while attached to the gas line. This often causes beer to back up a bit into the gas line, so I empty the gas lines separately, and repeat all this fuss until the foam and carbonation finally work themselves out (usually 1/3 of the way through the keg or so).

I have installed a fan-based cooling hose to push cool air to the dispensing tower as well, and the kegerator is otherwise well-insulated and runs at ~39 degrees. Each beer gets at least 2 weeks in the primary and two in the secondary before kegging. When I keg the beer itself from the secondary fermenter, I added 1/3 cup priming sugar well-boiled in fresh water, as advised by several resources I've consulted.

What can I change so I don't have to go through this extended process for each keg, and avoid wasting so much beer to overfoaming?


If beer is backing up into your C02 line it's possible it can harbor an infection. The fact that beer is backing up into your CO2 line also means the pressure in the keg is higher than the pressure you're applying. Later in your post you mention that you add sugar to carbonate in the keg; I'd suggest you use one method of carbonation, not both. I use forced CO2 at 32 psi and 35 F for two days, then crank the pressure down to serving pressure - 8 - 10 psi, depending on the style. BeerSmith has a good carbonation tool.


2) The mash efficiency from my all-grain process is consistently lower than the target O.G. in the recipe
I've used all-grain recipes from Northern Brewer, MoreBeer, and other sources. For ex, I brewed an IPA with a target O.G. of 1.072-1.076, but my actual O.G. turned out to be 1.063. Then I brewed a Belgian with a target O.G. of 1.068-1.073, but my actual O.G. turned out to be 1.054.

I use this grain mill:
http://www.homebrewing.org/Cereal-Killer-Grain-Mill_p_2310.html
and had a local shop guy set the gaps for me and test the milling. I made the gaps a touch smaller after the first batch, but the O.G. results were the same.

I've seen lots of posts from experienced brewers saying the crush is the primary determinant of efficiency. Get a "feeler gauge" from an auto parts store and measure the current roller gap. Assuming the experts are correct about the importance of the crush, adjust your rollers .005 inches closer and check the efficiency of your next brew session. Repeat as necessary until your efficiency hits a satisfactory point - or, until you get a stuck sparge. If the pre-boil gravity is still too low, boil longer and/or more vigorously to hit your desired gravity. It may take a lot of gravity measurements throughout the brew session to track the pre-boil gravity and volume as well as a couple of times during the boil and at the end of the boil. Read Tom Hampton's posts pinned at the top of the "All Grain" section of this forum; he explains the process better than I've seen anywhere else.

I've followed the strike temp, mash-out and rest, and sparge temps and time instructions as best as I can. Maybe I'm a few degrees off here or there, but I think it's all pretty close to targets.

Calibrate your thermometer(s) in ice water and boiling water. Consider buying a high-quality digital thermometer. If your mash temps are a few degrees higher or lower than you intend, your efficiency can suffer.

How can I increase my mash efficiency?

3) My finished beers seem to all have a slightly sour back-taste. Definitely well-drinkable, but it's there and hard to ignore. Would really like to refine to get rid of this problem.

You could be getting an infection from the beer backed up into your gas line. In addition to the comments above, consider adding a check valve to your gas line.

I also make a yeast starter 1-2 days before brewing per this method:
http://beersmith.com/blog/2008/04/01/making-a-yeast-starter-for-your-home-brew-beer/.

After flameout, I use an immersion wort chiller and get the beer down to the target fermentation temp within 20-30 minutes. The primary fermentations are taking place in a 6.5 gallon glass carboy, and are always well-active within a day of pitching the yeast after brewing. I leave the fermenters in my office, which has an ambient air temp of about 66-71, just about right for most of the yeasts/ales I'm brewing (though I do understand the temp wavers a bit in that range). After time in the secondary, I rack the beer to the corny keg, attach the co2 line to top-out the headspace, and then move the keg to storage in my cool, dark, ~50-55 degree basement until I'm ready to tap it.

The o-rings on my kegs also seem well in-tact, so if there is any contamination, I'm not sure where it could be coming from.

How can I remove the slightly sour taste from my brews?

Here are all the other relevant general details I can think of regarding my setup:
- After brewing flameout, I sanitize everything that touches the brew in a big sink of StarSan.
- I brew directly to 5-gallon corny kegs and dispense them via a 3-tap kegerator featuring a 20-gallon Co2 tank, bevlex hosing, and brass fixtures.
- I clean the lines with FiveStar PBW after each keg is emptied.
- Kegerator gas tank is set at about 10psi.
- I recently replaced the dispensing lines completely and spec'd them to what I read would be appropriate (~6 feet hose length from keg to tap)

I think most dispensing calculators assume 3/16 inch inside diameter lines. I saw a great improvement when I moved from 1/4 to 3/16. You can also get longer dispensing lines; I think mine are about nine feet.

Advice greatly appreciated! I put a bunch of time into brewing and I'd really love to step up my game so I can be proud to share my beers with more people.

Cheers,
-Jason

Click to expand...

propsout said:

1) When I put on a new keg in my kegerator, there's always a lot of wasted beer and time getting it to dispense with minimal foam and proper carbonation.
Sometimes, there's an initial huge blast of foam in each pour, but the beer itself is not well-carbonated. So I pour off the foam for a while, and then try to force-carbonate the keg by rolling it while attached to the gas line. This often causes beer to back up a bit into the gas line, so I empty the gas lines separately, and repeat all this fuss until the foam and carbonation finally work themselves out (usually 1/3 of the way through the keg or so).

I have installed a fan-based cooling hose to push cool air to the dispensing tower as well, and the kegerator is otherwise well-insulated and runs at ~39 degrees. Each beer gets at least 2 weeks in the primary and two in the secondary before kegging. When I keg the beer itself from the secondary fermenter, I added 1/3 cup priming sugar well-boiled in fresh water, as advised by several resources I've consulted.

What can I change so I don't have to go through this extended process for each keg, and avoid wasting so much beer to overfoaming?

Click to expand...

propsout said:

2) The mash efficiency from my all-grain process is consistently lower than the target O.G. in the recipe
I've used all-grain recipes from Northern Brewer, MoreBeer, and other sources. For ex, I brewed an IPA with a target O.G. of 1.072-1.076, but my actual O.G. turned out to be 1.063. Then I brewed a Belgian with a target O.G. of 1.068-1.073, but my actual O.G. turned out to be 1.054.

I use this grain mill:
http://www.homebrewing.org/Cereal-Killer-Grain-Mill_p_2310.html
and had a local shop guy set the gaps for me and test the milling. I made the gaps a touch smaller after the first batch, but the O.G. results were the same.

I've followed the strike temp, mash-out and rest, and sparge temps and time instructions as best as I can. Maybe I'm a few degrees off here or there, but I think it's all pretty close to targets.

How can I increase my mash efficiency?

Click to expand...

propsout said:

3) My finished beers seem to all have a slightly sour back-taste. Definitely well-drinkable, but it's there and hard to ignore. Would really like to refine to get rid of this problem.

I also make a yeast starter 1-2 days before brewing per this method:
http://beersmith.com/blog/2008/04/01/making-a-yeast-starter-for-your-home-brew-beer/.

After flameout, I use an immersion wort chiller and get the beer down to the target fermentation temp within 20-30 minutes. The primary fermentations are taking place in a 6.5 gallon glass carboy, and are always well-active within a day of pitching the yeast after brewing. I leave the fermenters in my office, which has an ambient air temp of about 66-71, just about right for most of the yeasts/ales I'm brewing (though I do understand the temp wavers a bit in that range). After time in the secondary, I rack the beer to the corny keg, attach the co2 line to top-out the headspace, and then move the keg to storage in my cool, dark, ~50-55 degree basement until I'm ready to tap it.

The o-rings on my kegs also seem well in-tact, so if there is any contamination, I'm not sure where it could be coming from.

How can I remove the slightly sour taste from my brews?

Click to expand...