Slow fermentation..

[Stauffbier]

I'm re-posting this from another one of my threads..

Ok.. I'm at 18 days now. This batch is still moving very slow, and starting to worry me. It's still dropping by .001 every day.
OG was 1.071
Predicted Final Gravity is supposed to be between 1.015 to 1.018
I took a reading tonight, and It's at 1.021...
Should I just let it keep chugging along at this slow pace, or should I order some more yeast and re-pitch? 18 days just seems way too long to ferment out... I've read that some people leave their lagers in primary for as long as a month before racking to secondary for lagering. Can It actually take that entire month to ferment out?

 

[jester5120]

if it's a lager then you should try doing a d-rest. let it warm up to room temp for a day or 2. that'll get the yeast to be a little more active and it'll get rid of some of the off flavors. that's very common practice to do in between primary fermentation and lagering.

 

[Stauffbier]

Believe it or not, I have already done that. I brought it up to 62 for 2 days when my gravity was half way to finishing gravity.. that was about 8 days ago. I should mention that I'm using the white labs San Francisco Lager yeast... Maybe 62 wasn't a high enough temp for d-rest with this yeast?! I also added a yeast nutrient today, which I hope was not a bad thing to do.

 

[wailingguitar]

Sounds fine to me. I have had big lagers take a long time to ferment, this isn't unusual. Remember; slow, steady ferment = clean beer... You'll have a nice doppelbock I'm sure.

 

[Stauffbier]

That's what I was hoping to hear! Thanks!

 

[osagedr]

Don't "tinker" with it anymore than you already have. Who really gives a crap if it's 1.021 vs. 1.018? You think you can taste the difference? Repitching for three to six gravity points would be pure insanity.

You've done the right thing so far by keeping an eye on your SG and getting the d-rest out of the way (not sure I get why you did it at 50% attenuation but not much you can do about it now; I would have suggested a d-rest around 1.026). Let the beer do its thing; leave it alone; rack it when it finally does stop, and let the lagering begin. Keep it cold until next March, then enjoy!

 

[Stauffbier]

(not sure I get why you did it at 50% attenuation but not much you can do about it now; I would have suggested a d-rest around 1.026)!

I was pointed to an article on this web site that said to do it at 50%. I've heard some people say it should be more like 75%?! Next time I'll wait a bit longer for d-rest...

 

[Stauffbier]

This is the info I was going by..

https://www.homebrewtalk.com/f13/preventing-diacetyl-hold-butter-please-70438/

 

[osagedr]

This is the info I was going by..

https://www.homebrewtalk.com/f13/preventing-diacetyl-hold-butter-please-70438/

I remember reading that thread long ago; the part about being halfway to FG when starting a d-rest (I guess it depends on how gradually temperature is raised at that point) never caught my eye so it's certainly not your fault for following what you thought was good advice. I think most lager brewers making a 1.050 beer with an expected FG of 1.010 would agree 1.030 is too early to start a d-rest; personally I would go at 1.020 at the earliest.

Still, thank you for pointing that out; it makes me feel better about occasionally starting a d-rest a bit on the early side and gives me hope that your beer will be okay.

 

[Stauffbier]

I've decided to just RDWHAHB and leave it alone for a couple weeks. I'm not even going to check gravity again until then...

Thanks for the advice!

 

[jester5120]

yeah it'll all be good. lagers usually have some residual sweetness in them anyhow and since you're not that far off on your gravity you'll be fine. either way it's gonna be beer and that's what really matters