Kegging and Odd Flavours

[Bax]

Hey guys,

Well it's been a little while now since I got my first BIAB down. I made a Galaxy Golden Ale.

I cold crashed and then transferred direct to the keg.
Prior to dumping it into the keg. I connected up the gas and I went through a few cycles of pressuring the keg, venting, pressurising and venting.

I then opened the lid, dropped in the hose for transfer. And slowly trickled into the keg.

I then sealed the keg back up. Sprayed the top with starsan. Cleaned up. And then force carbed.

Had a drink a few days later, and it was delicious. Exactly what I was chasing.

During the next few days I had a gas leak, one of my duotight fittings failed. So I turned off the gas and let it sit for another couple of days until I fixed that up.

Anyway, cracked it open again a week or so later, and it was completely different. All the hops were gone. The aroma was gone. It was just a malty/bitter beer. Not much else.

What went wrong? I don't think it's oxidised, I don't see how it could have.
Infection?

Brand new keg, full of starsan moments before transfer.
Maybe a small infection in primary before I even transferred, but nothing looked or smelt odd initially?

Thoughts?

 

[MHB]

Fast fading of hops is often a sign of oxidization.
It can be from infection although that is more likely to show other signs before it degrades hop character.
It takes surprisingly little O2 to do harm and it isn't necessarily consumed so it can go on destroying flavours, what is called a free radical, think Pacman going chomp chomp, it doesn't stop.
To eliminate this you need to look at your whole process and minimise the chance of O2 pickup all the way from mashing in to packaging.
To get very low DO (Dissolved Oxygen) is a bit of a mission, there are several threads on the subject that it might be worth having a read of. One thing I will say is that repeated purging of a keg isn't as effective as many people would think.
If you want to get really low DO, try filling the keg completely with de-aired water (well de-oxygenated really) either freshly boiled water or water with a smidge of Metabisulfite, then blow the water out of the keg with CO2.
But the right answer is really a whole of process approach.
Mark

 

[Bax]

Thanks Mark great info.

I’ve seen comments made about having the keg full of star san and then using the co2 to purge the starsan out.

My issue then is what’s the point when you’re just lifting the lid to transfer anyway. I understand it’s heavier and shouldn’t be displaced as easy but reality is we are taking all these steps to just lift the lid seems backwards.

Looks like I’ve got some research to do as my preferred style is very aroma hop forward and I obviously can’t consume 19L of beer in a week.

Im assuming if I fill with boiled water.
Pressurise the keg.
Drain the water via tap.
Connect to the Gas In line to fill Keg
Syphon out as normal.
Would probably be a safer method?

 

[MHB]

I would fill through the Out Post (from the bottom), either fit a disconnect to the Gas Post with a line going to a bucket to act a blow off for any foam/excess. Or open the PRV.
Just be dam sure you don't have any hop fragments going down the line to the disconnect/post or it will fill up with hop bits in seconds, an inline filter would be a good call if you lean on the hops hard.

I don't regard detergent and phosphoric acid as no-rinse! A tiny bit of Met I could live with, SO2 is an approved beer additive. I think its a lot easier to just fill the keg with tap water, add enough Metabisulfite (say 1/2 a Campden tablet) to kill any O2 and Cl leave for half an hour then blow it out. Remember to that as the water cools it will start taking up Oxygen and that boiling wont get rid of all the Cl and any Chloramines in the water, Met will.
Truth is most of the mega-swill has some added as a preservative. Way less than they use in wine making but some.
Mark

 

[dblunn]

Hi Mark, a quick question about usage rates if I may. I have some powdered Potassium Metabisulfite and I'm guessing that a Campden tablet weighs about 4g, does that sound about right to you?
Regards, Dave

 

[MHB]

Typically contain 0.44g of Pot or Sodium Metabisulfite. enough to de-chlorinate 75L of tap water.
For de-oxidisation about 1/2 a tablet in a 19L keg should do the job.
Not sure how good your scales are, but a pincn of Pot Met should help.
Mark

 

[dblunn]

Typically contain 0.44g of Pot or Sodium Metabisulfite. enough to de-chlorinate 75L of tap water.
For de-oxidisation about 1/2 a tablet in a 19L keg should do the job.
Not sure how good your scales are, but a pincn of Pot Met should help.
Mark

Ah, I thought there was a 4 in there somewhere, what's an order of magnitude among friends. Thanks for clearing that up and the advice on usage rates.
I have been using a pinch of powdered Pot Met for de-chlorinating (sp) my brewing liquor but I didn't know it would de-oxygenate (sp) water as well.
All the best, Dave