[roguejim]

Is pediococcus a sanitation related issue, or something else?  Denny has told me that it can cause diacetyl.  I'm trying to eliminate possible causes as to diacetyl in a 1.051 APA, fermented with 1 packet of US-05 for 10 days at 66F.  I did not take a final hydro reading, assuming 10 days was ample enough time.

[denny]

It may have been enough time to reach FG but maybe not enough time for the yeast to actually finish its other work.

[majorvices]

pedio is definitely a sanitation issue and can cause diacetyl. Also, oxidation can cause diacetyl to reform in the finished beer.

[denny]

Also, oxidation can cause diacetyl to reform in the finished beer.

Ooohhh, good point, since I know the beer Jim is talking about was bottled from a keg.

[roguejim]

Also, oxidation can cause diacetyl to reform in the finished beer.

Ooohhh, good point, since I know the beer Jim is talking about was bottled from a keg.

Well, that diacetyl must have reformed in a period of 6 days then.  Bottled on Monday, tasted on Sunday.  Was there much head space in those bottles, Denny?  I thought there was very little, plus I used Oxy Caps.  Not arguing with you guys, just getting all the info out there.

[denny]

Nope, virtually no head space.  Several people wanted to know how you did that!

[majorvices]

Did you purge the kegs with co2 when racking? was there a leak in your racking cane? Did you purge the bottles with co2? Any of those times could have introduced o2. Not idea if oxidation caused it, just sayin'.

[roguejim]

Did you purge the kegs with co2 when racking? was there a leak in your racking cane? Did you purge the bottles with co2? Any of those times could have introduced o2. Not idea if oxidation caused it, just sayin'.

I never thought about purging the kegs when racking...I do purge the headspace after racking.  No leaks that I can see in my Super Siphon.  I'm not sure how I would purge the bottles given my equipment, i.e., QD+hose+cobra tap.  I insert a small length of vinyl tubing into the cobra tap nozzle for bottle filling.  Not ideal, I know.  Bottles were filled practically to the brim, and capped with Oxy Caps.

Wouldn't oxidation have been detected by the taste testers in some other way other than by merely the presence of diacetyl?  Thanks for the comments guys.  I'm still learning. 

[bluesman]

10 days at 66F with US05 was probably enough time for the yeast to consume any residual diacetyl...did you taste the beer upon racking?

Also a small tip...after kicking a keg. I clean the keg with hot water then it gets a hot PBW soak overnight. The keg then gets another hot rinse and a quart of starsan solution shaken up inside.I then purge the keg completely with CO2...pulling the pressure relief valve multiple times to evacuate O2. I store the keg pressurized with CO2 until it's ready to be filled. When ready to fill I just release the pressure and rack the beer into the CO2 filled keg.

This method mitigates potential oxidation.

[thomasbarnes]

Is pediococcus a sanitation related issue, or something else?  Denny has told me that it can cause diacetyl.  I'm trying to eliminate possible causes as to diacetyl in a 1.051 APA, fermented with 1 packet of US-05 for 10 days at 66F.  I did not take a final hydro reading, assuming 10 days was ample enough time.

I'm not sure that pedio infection is your problem here.

As others have pointed out, pedio IS related to sanitation, but it takes some time to develop. It's more likely that you're just getting normal diacetyl due to yeast action.

If you're getting loads of butterscotch/diacetyl and also lactic (i.e., yogurty, without much aroma) sourness, you might have a pedio infection. If you're just getting lots of diacetyl, but not much sourness, you probably don't have a pediococcus infection, but you do have a fermentation issue.

[denny]

I can tell you that the people who tasted Jim's beer found low levels of diacetyl, and of the 8-9 tasters only 4 mentioned it (one of whom was me).  There were no other obvious flaws in the beer and no other sign of infection.

[roguejim]

Thanks for the update there, Denny.  8 or 9 tasters?  Wow!  I guess I won't beat myself up over the 4 judges tasting low levels of diacetyl, although I will be using other liquid yeast strains for comparison.

[morticaixavier]

Did you purge the kegs with co2 when racking? was there a leak in your racking cane? Did you purge the bottles with co2? Any of those times could have introduced o2. Not idea if oxidation caused it, just sayin'.

I never thought about purging the kegs when racking...I do purge the headspace after racking.  No leaks that I can see in my Super Siphon.  I'm not sure how I would purge the bottles given my equipment, i.e., QD+hose+cobra tap.  I insert a small length of vinyl tubing into the cobra tap nozzle for bottle filling.  Not ideal, I know.  Bottles were filled practically to the brim, and capped with Oxy Caps.

Wouldn't oxidation have been detected by the taste testers in some other way other than by merely the presence of diacetyl?  Thanks for the comments guys.  I'm still learning.

purgeing kegs: If you add co2 to an empty (air filled) keg and then release the presure and then repeat you will not get all the o2 out. yes o2 is lighter than co2 but it is still a gas. alchahol is lighter than water but if you pour water into a glass of rubbing alchahol until it overflows an amount equal to the volume of alchahol you do not end up with pure water. fluids mix. They may not stay mixed but they do mix.

I like to fill the keg to the very brim, as close as I can get to 0 air space, with sanitizer and then force that out with co2. the result should be an almost perfect absence of o2 (almost perfect because 1. I can't seem to get the keg totally full of  liquid and 2. some o2 that is disolved in the sanitizer solution will probably come out as it drains and thus introduce some tiny amount.)

does this make a difference? I have no idea. this is how I have always done it but it seems like it could make a difference in the long term.

[bluesman]

Did you purge the kegs with co2 when racking? was there a leak in your racking cane? Did you purge the bottles with co2? Any of those times could have introduced o2. Not idea if oxidation caused it, just sayin'.

I never thought about purging the kegs when racking...I do purge the headspace after racking.  No leaks that I can see in my Super Siphon.  I'm not sure how I would purge the bottles given my equipment, i.e., QD+hose+cobra tap.  I insert a small length of vinyl tubing into the cobra tap nozzle for bottle filling.  Not ideal, I know.  Bottles were filled practically to the brim, and capped with Oxy Caps.

Wouldn't oxidation have been detected by the taste testers in some other way other than by merely the presence of diacetyl?  Thanks for the comments guys.  I'm still learning.

purgeing kegs: If you add co2 to an empty (air filled) keg and then release the presure and then repeat you will not get all the o2 out. yes o2 is lighter than co2 but it is still a gas. alchahol is lighter than water but if you pour water into a glass of rubbing alchahol until it overflows an amount equal to the volume of alchahol you do not end up with pure water. fluids mix. They may not stay mixed but they do mix.

I like to fill the keg to the very brim, as close as I can get to 0 air space, with sanitizer and then force that out with co2. the result should be an almost perfect absence of o2 (almost perfect because 1. I can't seem to get the keg totally full of  liquid and 2. some o2 that is disolved in the sanitizer solution will probably come out as it drains and thus introduce some tiny amount.)

does this make a difference? I have no idea. this is how I have always done it but it seems like it could make a difference in the long term.

...however if you hook up the CO2 to the dip tube post and open the P.R. valve you will evacuate most if not all of the O2 in the keg.

[morticaixavier]

Did you purge the kegs with co2 when racking? was there a leak in your racking cane? Did you purge the bottles with co2? Any of those times could have introduced o2. Not idea if oxidation caused it, just sayin'.

I never thought about purging the kegs when racking...I do purge the headspace after racking.  No leaks that I can see in my Super Siphon.  I'm not sure how I would purge the bottles given my equipment, i.e., QD+hose+cobra tap.  I insert a small length of vinyl tubing into the cobra tap nozzle for bottle filling.  Not ideal, I know.  Bottles were filled practically to the brim, and capped with Oxy Caps.

Wouldn't oxidation have been detected by the taste testers in some other way other than by merely the presence of diacetyl?  Thanks for the comments guys.  I'm still learning.

purgeing kegs: If you add co2 to an empty (air filled) keg and then release the presure and then repeat you will not get all the o2 out. yes o2 is lighter than co2 but it is still a gas. alchahol is lighter than water but if you pour water into a glass of rubbing alchahol until it overflows an amount equal to the volume of alchahol you do not end up with pure water. fluids mix. They may not stay mixed but they do mix.

I like to fill the keg to the very brim, as close as I can get to 0 air space, with sanitizer and then force that out with co2. the result should be an almost perfect absence of o2 (almost perfect because 1. I can't seem to get the keg totally full of  liquid and 2. some o2 that is disolved in the sanitizer solution will probably come out as it drains and thus introduce some tiny amount.)

does this make a difference? I have no idea. this is how I have always done it but it seems like it could make a difference in the long term.

...however if you hook up the CO2 to the dip tube post and open the P.R. valve you will evacuate most if not all of the O2 in the keg.

that's my point. doesn't matter if you add the co2 to the bottom or the top, unless you go incredibly slow, there will still be alot of mixing, gases mix even better than liquids. I am sure it's fine I am just saying that if the goal is to remove as much o2 as possible you have to start with a medium so much more dense than air that it will not mix.