Diaceytl rest, is it time yet?

[losman26]

Hi, I'm brewing up my first lager, using one pack of wyeast 2124 bohemian lager yeast with an original gravity. I pitched the yeast 9 days ago, but signs of fermentation didn't start until 7 days ago.

My gravity reading right now is at 1.017 and the project gravity is supposed be right around 1.010. I'm getting 1 bubble every 6 secs in the airlock. Should I go ahead and start the d-rest, or wait it out a little longer?

Thanks

 

[BigB]

I would go ahead and do it... unless your OG was really low, you should be about 75% complete now.

 

[fxdude]

Agreed, sounds like it's time, good luck!

 

[losman26]

Thanks again. Do you guys recommend that I gradually raise the temp, or just throw the carboy in the room at room temp?

 

[BigB]

Just move it to room temp. Yeast are not shocked by warming up quickly like they are when the temp is dropped quickly.

 

[losman26]

Should I go two days for the D-rest. How do I know when to stop? I didn't taste a lot of buttery flavor like I expected. You transfer to secondary after the d-rest, right? Also, in the lagering phase where should my temps be at? I here lowering it gradually, but to how low? My wine fridge only goes down to 46, but I could put it outside to get it in the 30's if need be.
Thanks.

 

[losman26]

I would go ahead and do it... unless your OG was really low, you should be about 75% complete now.

OG was 1.040

 

[BigB]

I typically go 3-4 days on the d-rest, but that is just my personal preference. The d-rest is done when the beer reaches FG. There is a dispute as to how fast you drop the temps, some say its unnecessary, others say it is. I'm on the fence, but I do slowly lower the temp by 2-4 degrees per day just as a precaution. I prefer to lager at 35 degrees for 42 days. Many lager at 38-42. It is a matter of preference. EDIT: You could lager at 46, but most people feel that you get a cleaner taste profile by lagering cooler.

 

[fxdude]

I believe you're supposed to do the rest towards the end of fermentation, not once it's finished. That seems to be the majority of what I've read. I do usually raise the temps gradually over a few days though.

 

[fxdude]

I usually take a few days to raise the temps, one to two day hold depending on whenever I reach my target FG, then two to three days to drop the temps back down. You should lager around 15 degrees below your fermenting temp so if you fermented at 54 you should lager around 39. I also lager around 35 though

 

[fxdude]

Sorry, forgot to mention I transfer to a secondary before I start dropping the temps back down.

 

[losman26]

Thanks again. I have raised the temp in the wine fridge to 60.
Airlock is moving a little faster and krausen is slightly higher.
Did I do it too soon? I'm guessing this is perfectly normal to get
A slight increase in c02

 

[fxdude]

yup, totally normal, little yeasties are picking up the pace now

 

[losman26]

So, I guess I'm exactly right on schedule right? Original gravity was 1.040, target gravity is 1.010, right now I'm at 1.017. I've read a lot to do the d-rest at about 2/3 of the way towards the target. Is this correct? Is 60F a good temp for the first day of the d-rest or should I go higher. My room temp is usually around 68F and my wine fridge will go all the way up to 64.

 

[1Mainebrew]

Bring the temp up to room temp for the D-rest. Rest for 3-4 days (you would be suprised how long it takes to bring a 5 gallon batch of beer up from 50 to 68). Then you rack to secondary and begin the lagering process. The purpose of slowly decreasing the temp to lagering temp is to promote yeast activity even at very low temperatures to create that very clean crisp flavor profile we all expect from lagers. Otherwise with a crash cool, you will make your yeast flocc out. Both work really well. I'm not convinced its necessary to drop the temp slowly. I've made lagers where I dropped it to lagering temp directly after the D-rest and they finished just as clean as could be. Have fun brewing it up.

 

[g-star]

Good advice here. Next time I would advise making a starter, something that is really mandatory for lagers. 7 days lag time is excessive. Withe the right sized starter, you should see activity in 12-24 hours.

 

[1Mainebrew]

Yeah the starter is another topic all together

 

[BigB]

I sincerely doubt he had 7 days of lag time. I've made numerous lagers and often there is little to no krausen or airlock activity, yet there is plenty of fementation.

 

[jfrank85]

Good advice here. Next time I would advise making a starter, something that is really mandatory for lagers. 7 days lag time is excessive. Withe the right sized starter, you should see activity in 12-24 hours.

He pitched 9 days ago and got activity 7 days ago. 2 days of lag. Still not optimal but better than a full week.

 

[losman26]

Yeah it was pretty much over 30 hours before I say any activity. I had it at room temp as well in the beginning. I did pitch the yeast at a low temp, slightly below 60F.

 

[g-star]

I mis-understood, thanks for the clarification. 30hrs is still on the long side, and pitching warm is asking for trouble, IMO. With the right sized starter an good aeration, you can pitch at 44F and let it slowly rise to 50F. This seems to produce the cleanest lagers, IME.

 

[1Mainebrew]

I mis-understood, thanks for the clarification. 30hrs is still on the long side, and pitching warm is asking for trouble, IMO. With the right sized starter an good aeration, you can pitch at 44F and let it slowly rise to 50F. This seems to produce the cleanest lagers, IME.

that cannot be emphasized enough!

 

[losman26]

I didn't use a starter, so I guess that could explain the huge lag-time.

 

[losman26]

So I've been doing the Diacetyl rest since friday (3 Days), and there seems to still be some Co2 with 1-2 bubbles per minute in the airlock. Right now it is at 68 F, and tomorrow is day 4. What is the longest I can do a D-rest for without picking up off flavors? If I still notice co2 activity is it too early to rack?

 

[fxdude]

Fermentation can be complete even with airlock activity, the warmed up liquid may just be releasing gas since it's been warmed up. Best way to know is to take a reading but I would start cooling it down now, that will probably take a few days anyways.

 

[BigB]

^Right. You need to do a hydrometer reading. But likely you have reached FG. If so, I would start lowering the temp slowly. That way if there is still some fermentation activity, the yeast won't go dormant from a sudden temperature change.

 

[losman26]

Well today I did a hydrometer reading and it was 1.008, so racked it to the secondary. I'm just really concerned about the large head space in the secondary as there doesn't seem to be much co2 activity going on. Should I replace the airlock with a regular stopper to absorb some co2? Or just leave it be.

 

[1Mainebrew]

Can you purge with CO2?

 

[BigB]

Leave it be. The co2 is in solution and will continue to come out enough to layer the top. Just don't go splashing the carboy around. I use 6.5 gallon glass carboys for 5 gallon batches all the time. Never had an oxidation issue.

 

[losman26]

I actually took a look at the airlock 5 minutes after posting this, and it seems to be going now at around 5-6 per min, so I think I'm ok. Thanks again for all your help!