Diacetyl Rest Too Long?

[Mutant]

I was fermenting an 'American Lager' in three different kegs. At the end of the ferment, I ramped up the temps for a diacetyl rest. I then transferred the first keg to a secondary keg by running through a filter. The FG was 1.010 and it tasted nice. The next day, I transferred the second keg getting the same FG, but the result was a different taste that I couldn't put my finger on. Today, I will be transferring the 3rd keg. What are the possible consequences to the beer if the diacetyl rest is too long? I may try to taste the three kegs side-by-side when I can get taps hooked up. Given the FG were fundamentally the same, I don't believe the taste difference is that it is just slightly drier. I am hoping that the lagering will polish up whatever this difference is.

 

[Jag75]

No , there's not a definitive time length on diacetyl rest that I'm aware of. I think it's more of an issue cutting it short rather then longer, not allowing the D rest to be completed.

If you have the same batch , split into 3 different kegs to ferment there really shouldn't be anything different. Especially if all 3 were fermented at same temp , had proper amount and same yeast ect....

First thing that pops into my mind is maybe it was something in your keg that is giving it an off taste. If you could express what that flavor is , it would be easier to pin point.

 

[Mutant]

I'll need to get the third keg transferred, set up some taps, and compare. I couldn't put my finger on what I was tasting different. In some ways, it tasted drier but the FG was fundamentally the same. Almost all batches of beer/ale that I make are developed around three kegs at a time. It maximizes what fits into a kegerator, keeps everything pretty much consistent, and allows me to transfer to secondary without exposure to oxygen. It'll take a couple days to get everything transferred, chilled, and tapped for comparison.

 

[dmtaylor]

Beer will taste slightly different when placed in different fermenters. This is normal.

I find that diacetyl often takes up to 3 to 4 weeks to clear up completely... at least for those with a sensitive palate. There is nothing wrong with leaving a lager on a diacetyl rest for several weeks. So, an extra day or two won't hurt anything, and might even help.

I think you're just getting the slight variability from unknown variables from the fermenters themselves -- geometry, slight contam, slight temperature differences, etc. Nothing to worry too much about.

 

[hotbeer]

Might be just from other things that change the beer as time goes by. Did you taste the first keg and see if it tasted the same as when you kegged it?

How soon after it reached FG did you start the rest? how long was the rest and how long between sampling the two?

 

[Jag75]

Just a note , diacetyl rest should be done before ypu reach FG. Normally when your 3-5 points off. I will start it when it's about 75% done slowly ramping up the temp each day .