Fermentation Drive for High Gravity Lager - Doppelbock

[Noob_Brewer]

So, Im still new to brewing lagers as I've only brewed two others before (czech dark) with Imperial Urkel, but now Im fermenting a Doppelbock using a new (to me) yeast strain, WLP833 German Bock Lager. I'm currently only at day 3 of fermentation at 50F, but Im curious as to two things:

1) when do ya'll start increasing temps for the D-rest, and
2) how fast do you increase the temps to d-rest. Ive read plenty here and on other sites and opinions seem to vary wildly from "let it ride at 50-52 for two weeks" to "start increasing temps by 1 degree per day at around day 4 when fermentation starts to slow".

For more information: my OG was 1.093 and expected FG is 1.024 - 69 total point drop to FG. I used brewers friend for yeast count and based on a 2.0M cells/ml/P pitch rate, I needed ~920B cells. So I started with three packs of fresh WLP833, ran a 3.25L starter and then crashed to decant and stepped it up once with another 3.25L starter to get me there. It was a HUGE starter and by my estimation the lag phase was only about ~10-12hrs (it started while I was asleep). Oxygenated well at pitching as well. So I think I got a solid batch of healthy yeast.

As of right now, by my tilt readings (I know absolute values aren't perfect but its a data point that I use) are 1.063 (a little over 3 days post pitch) so Im 30 points down from OG. I've noticed the krausen falling today, but airlock activity is still consistently galloping along.

So with this information, how do ya'll determine when to start raising temps for the d-rest and how fast do you get the temps there? I was planning ultimately on increasing the temps to 65F for the d-rest but want your opinions on when to start this and how fast should I ramp it.

Thanks in advance.

 

[Red over White]

It sounds like you have ticked all the boxes and may not even need a d rest. You can do a forced test to determine if it is necessary, this link has some good info about it.

https://escarpmentlabs.com/blogs/resources/the-forced-diacetyl-test

 

[HighVoltageMan!]

It's really hard to say without seeing it and watching it. I've brewed with 833 in the past and it used to be one of my favorite lager yeasts. I still like 833 yeast and in my experience it isn't prone to diacetyl. The d-rest can be started near the tail end of fermentation, but that depends on so many things that it is hard to say when it should happen. Typically it's when the beer has 2-4 gravity points left. The key to a d-rest is to preform it when the yeast is still active.

I usually preform a d-rest when I start to see the airlock slow, not very scientific, but it works. The temperature doesn't need to hit 65F, high 50's is plenty high. Then I leave it at that temp until it hits it's FG.

 

[OLBrews]

I have a Doppelbock going right now, also with 833 yeast.
I will typically start raising the temperature about 4 gravity points from FG and start spunding at the same time. However, if the gravity trace from the Tilt starts to plateau I'll consider bumping the temperature earlier. I typically adjust 3 degrees F twice per day.
Your yeast process looks good. If you can easily take a sample give a forced diacetyl test a go - it has helped me assess lager yeasts I haven't brew with prior.

 

[Noob_Brewer]

Thanks for the input all! @HighVoltageMan! I agree completely in that visual inspection of the ferm process gives solid info on when to start ramping up for D rest. Ideally a few points shy of FG is great, but in my case since I don't have the expereince with this beer style or yeast that can be tough sometimes too. @OLBrews your timing on adding your Tilt profile gives me a good understanding of this yeast. Mine seems to be tracking similar to yours but perhaps at a tad slower rate. Im now 4days and 7hrs into my fermentation and still have some krausen (although its still falling) and the airlock is still consistent. Seems you started ramping around day 6 when your gravity was pretty close to FG it seems. What was your actual OG for this brew?

Thanks again all, this has been helpful. I'm pretty patient but just wanted some advice so I can be more strategic when the time comes to start letting the temp rise for d-rest. Just want this to finish out the way I expect it. Fun times!

 

[OLBrews]

Thanks for the input all! @HighVoltageMan! I agree completely in that visual inspection of the ferm process gives solid info on when to start ramping up for D rest. Ideally a few points shy of FG is great, but in my case since I don't have the expereince with this beer style or yeast that can be tough sometimes too. @OLBrews your timing on adding your Tilt profile gives me a good understanding of this yeast. Mine seems to be tracking similar to yours but perhaps at a tad slower rate. Im now 4days and 7hrs into my fermentation and still have some krausen (although its still falling) and the airlock is still consistent. Seems you started ramping around day 6 when your gravity was pretty close to FG it seems. What was your actual OG for this brew?

Thanks again all, this has been helpful. I'm pretty patient but just wanted some advice so I can be more strategic when the time comes to start letting the temp rise for d-rest. Just want this to finish out the way I expect it. Fun times!

The OG was 1.087 for this batch. It was pitched directly on yeast cake from a prior batch of a Dunkel, so the yeast was good to go.

 

[Noob_Brewer]

The OG was 1.087 for this batch. It was pitched directly on yeast cake from a prior batch of a Dunkel, so the yeast was good to go.

Thanks! By the looks of the graph it seems you ramped it up to 60 then ultimately 63 for the D-rest set points? Hard to tell with the temp fluctuations. Thanks again!