Consistent Slow Fermentations After Switching to Plate Chiller

[mull0263]

Greetings,

Hoping the community here can help provide some insight on what is becoming a very frustrating problem for me.

I have been all-grain brewing for a number of years and generally haven't had any problems with stuck fermentations and I always use a starter for my 10 gallon batches. I recently upgraded my system to a Brutus 10(ish) with a plate chiller. Since I have made this transition I have had six straight batches with vveeerrrryyyy slow fermentations. I have used a starter for each batch, and other than having new kettles and pumping my wort, the plate chiller is really the only new step in my process instead of my old immersion chiller.

I do not recirculate my wort while chilling and the best conclusion I can come up with is that my wort isn't getting enough oxygen when going from brew kettle, through the chiller then to my carboys. I generally have vigorous fermentation for 24-48 hours then pretty much crickets - the beers have all fully fermented, but it has taken over one month in each case.

Anyone have any additional thoughts on this? Would whirlpooling or stirring my wort before cooling help?

Thanks!

 

[kombat]

Even after just reading the thread title, I was thinking "lack of oxygen," but it seems that's already occurred to you. I would recommend trying an oxygenation system and seeing if that makes a difference. Other than that, make sure you're pitching plenty of healthy yeast. For 10 gallon batches, that would be at least a 5 liter starter for ales.

 

[jddevinn]

Have you measured the gravity at the 48 hour mark? Depending on the yeast strain, if you have a good level of yeast and proper oxygenation you may be "done" after 48 hours.

 

[mull0263]

Yes, I have measured after ~48 hours on a couple of the batches with a couple of different strains and still have had a relatively high gravity after a fairly vigorous early fermentation. Usually, after transferring these batches to the secondary it seems to rouse the beer enough to finish fermenting eventually (1 month +), but attenuation has been noticeably low after sitting in the primary for a couple of weeks prior to moving to the secondary.

 

[jddevinn]

Hmm, do you end up chilling in one pass then? To the correct temperature? Are you filtering trub that you weren't before? A month is a very long time!!! (I'd discourage secondaries unless needed for fruit/experimentation solely based on oxidation)

 

[mull0263]

Yes, I am cooling in one pass and typically pitch once the wort is ~70 degrees (give or take a few degrees depending on conditions). I use the same filter for my trub in the Brutus that I did in my old kettle, so no changes there.

I am planning to brew again this weekend and I'm going to use my old immersion chiller instead of the plate chiller, while holding all other things constant, so we'll see if that solves the mystery (for my sanity, hoping it does, though I really liked the cooling efficiency of the plate chiller).

 

[aron2382]

If not enough oxygen is your issue try a carboy shake, or better yet throw a kettle screen on the end of your transfer hose and it will def aerate your wort.
Your issue isn't your chiller in terms of attenuation, although it may be causing the lack of oxygen which would result is a lack of yeast propagation, thus affecting attenuation.

Would love to hear your results on this.