Off flavor after kegging : Carbonic bite?

[mhall2013]

So I think I'm having an issue kegging. Last pale ale tasted better than the previous attempt. Adjusted water profile. Hit my target numbers throughout brew day. Fermented @ 66° for 3-4 days and then ramped temp to 70° for the rest of the first week. Gravity was stable so I racked into purged keg. Sample tasted great. Cold crashed and put it on gas. Sampled it as it carbed and it developed a sharpness and lack of flavor after a few days. I figured it was just carbonic bite. Let it go a few more days. Thought I would clear out the lines and faucet in case any yeast was left in lines after settling out. About 1.5 weeks in it was really good. Next day or so it had a sharp finish again and lacked flavor. I tried running lines out again just in case and no change. I even tried warming up the sample before tasting. Flavor didn't return. Tried de gassing the sample and tasting but no luck.

Maybe I've been impatient but pitching an active starter, keeping fermentation temps in low end of range, and ramping up temp as fermentation slows should have been enough to keep off flavors at a minimum and let the yeast clean up. I would have been more discouraged if I waited longer and had the beer turn like this. If the sample tasted good post fermentation why not move it to the next stage. I carefully racked into a purged keg and that was the only transfer from primary to keg. I wouldn't think oxidation would set in that fast. The color didn't seem to darken or anything. I don't think it was an infection.

I've googled and read other forum posts about off taste after kegging but none of them really point out the issue. I'm using the set it and forget it which @ 40° and 10 psi it should end up in the 2.2-2.3 range. I'm not burst carbing so I don't think it's over carbed. I'm at a loss.

Thought I was on the way to better beer but I was wrong. So over the past couple days I've been deep cleaning my gear and contemplating hanging up my hat. I still enjoy the process but tired of not seeing the results for the work I'm putting in. Feeling defeated.

[sneezles61]

Hold on brother... So your water is...? RO, Distilled, tap? Lets just brain storm a bit here... I will believe you're following something like bru'nwater? Sneezles61

[mhall2013]

Bottled water. Tested with Lamotte Brewlab. Adjusted with salts and lactic acid with ez water to calculated 5.4 mash pH.

[sneezles61]

Are you using a pH meter too? Its hard for something like malt, and even yeast for brewing to create a harsh bite... How much acid is the program having you add? My water, since it is full of buffers I add perhaps 2 tablespoons... That is for a 10 gallon batch... There are a few times I've added way more, but that was a few days after a rain... yes, my water can change that much... Sneezles61

[mhall2013]

No meter. 2ml 88% lactic for 8.5 gallons.

[WMNoob]

I'm with @sneezles61 , let's do little examination. How do you clean and sanitize your kegs. You say your sample tasted good at kegging so to me it sounds like this issue developed from there. Things I would ask are:

1. Has the keg been used successfully before?
2. Any possibility of an excess of Star San residual in the keg?
3. Any chance there was a source of contamination in the keg from cleaning?
4. You say you cold crashed and put it on gas. Did you pressurize the keg to seat the lid and leave it on gas while you cold crashed (chilled) it?

Something seems a buit weird to me here, especially since the sample at kegging time was good.

[squeegeethree]

What kind of beers are you making?

[sneezles61]

Thats between a 1/4 - 3/8 tbs... Have you tried a couple of different bottled waters too?
I wonder if the buffering capacity of the bottled water is so little that the amount of L.A. added, and I will go out on a limb, the crystal malt lowers the pH too much? Just putting ideas out there...
Just out of curiosity, put your input in as RO water, along with your grain bill and tell me what the L.A. amount is... Sneezles61

[mhall2013]

@WMNoob pbw soak full disassembly, lots of rinsing. Air dry upside down. Soak parts in star san. Fill keg with star san. Shake it a little. Let it sit then flip keg to soak top half. Push star san out with co2 until empty. Pulled prv filled keg through out port. Seated keg with 30 psi. Dropped to 10 psi to check for leaks. Then crashed.

@squeegeethree pale ale. 11 lbs 2 row, 1 lb munich, .5 lb c40.

[damian_winter]

Does it taste like soda water. Carbonic acid also has a metallic kinda taste too.. The chances that you build up enough of it to taste it is highly unlikely. A extremely over carbed beer i mean extremely over carbed you might pick up a hint of it.. You used buffers to lower your ph so you water profile was soft water. The softer water allowed you to get more out of your hops not in ibu but hop profile and now its kinda harsh tasting. Cold condition it for awhile and this will calm down. That would be my guess to what you have going. But the carbonic acid is highly unlikely.

[mhall2013]

I checked ez water against what beersmith 3 said in water section. I'll have to check it out again and see. I want to say one was -40 RA the other was much higher I think. I think (-)30-30 was suggested.

[brew_cat]

We will help you work through this don't give up. You say the beers used to come out good? What did you change? You think kegging carbonation may be the problem. How about brewing g the exact same recipe and bottle condition it

[sneezles61]

I don't follow what the number values are you displayed... I'm just curious about the amount of acid you then would add for pH correction... My take is too low pH causing harshness...
Just for fun... pour up a glass, take a small pinch baking soda, or perhaps a bit more to your glass to see if it goes away... You could do this with any of the brewing salts you add... You'd be amazed at how it will change just a pint! Sneezles61

[brew_cat]

Once you rule out the kegging which it's probably not then it's water. Next brew a batch with no additions. 50/50 bottled/distilled . You say you had the bottle water tested well they could have changed their source

[mhall2013]

I thought you were asking about residual alkalinity.

[mhall2013]

Tested with Lamotte brewlab.

[sneezles61]

Sorry, I'm left handed... not too good explaining me self... I say there is a lack of buffering... therefore, easy to add too much acid for pH lowering... Sneezles61

[brew_cat]

What I'm saying is maybe the batch of water you had tested is not the same as the water you brewed with. I think they may use different sources or the water changed.

[damian_winter]

Oh blame it on being left handed​ im left handed too.

[mhall2013]

I tested the water day before brew day. I was going to test all water combined but all the water had matching lot numbers so I tested one. I added 7g Gypsum, 4g Magnesium Sulfate, 4g calcium chloride to 8.5 gallons.
2 mL Lactic acid