repitching - Saflager W-34/70 Lager Dry Yeast

[m1k3]

I brewed 10 gallons of 1.061 Oktoberfest in two 5 gallon buckets with two packets of Saflager W-34/70 Lager Dry Yeast (properly rehydrated) for each 5 gallons (4 packets total).

Now I am going to repitch into a Baltic Porter (target 1.089)... it will also be a 10 gallon batch. I do not plan to wash the yeast or collect it in advance (sure probably a best practice but I don't plan to do that)

The Oktoberfest was done in two weeks and then spent one week at 35F.
(three weeks total from 1st brew to repitching)

Question 1:
Should I just dump the chilled Baltic Porter wort into the existing fermenters (once emptied) and then break up the yeast cake with a sanitized brewing spoon, then oxygenate?

Or it is worth using a clean fermenter and harvesting the yeast with a sanitized pyrex dish and pitching the yeast into the new fermenter?
(mainly it would be to avoid the funky krausen ring in the old fermenter but has a little more risk)

Question 2:
In the photo below you can see the 1/2"-3/4" of yeast... should I pitch as much of that as possible. (the photo was taken before cold crashing but as you can see it dropped pretty bright and not much more yeast fell out in the week at 35F)

Thanks!

 

[m1k3]

View attachment ImageUploadedByHome Brew1431569637.903945.jpg

 

[NTexBrewer]

I have done the pour and measure slurry two times with good results. I use Brewers Friends slurry calculator to estimate how much treat to use.
Fermentation takes off quickly.

 

[d3track]

Personally I'd harvest so I could use a clean and sanitized fermentor

 

[m1k3]

Personally I'd harvest so I could use a clean and sanitized fermentor

I think I'll go this route too.

But for the sake of argument, keeping the yeast in the fermenter that just produced a clean beer should give less of a chance from introducing infection, right?

Since I am only going with this single repitch and then I'm done with this yeast, I am sure my process will be clean enough. Also, there is so much yeast it should pretty much out compete any other wild yeast that would be introduced. I won't be doing any warm/extended aging of the beer either... but even so at 9.4%ABV bacteria would not find it a friendly place.

Since, it is a lager and I want low fusels and low esters... I think any over pitiching will be fine.

 

[m1k3]

Brewed the batch today, and I ended up doing it both ways.

Now, before you give me too much credit at being scientific and doing some actual research on my own...
It turned out there was a practical reason.

I collected the first 5-6 gallons in another bucket and dumped it on the yeast cake from on of the Oktoberfest fermentations.

Then I collect another 6-7 gallons in another bucket... this was going to be too much to repeat the same process... so I harvested the yeast and pitched it into the 7.9 gallon (wine style) bucket.

Because of over collecting the runnings the gravity turned out at 1.081 (instead of the 1.089 listed in Brewing Classic Styles).

Fermentation started with wort bubbling out the top when I came to check on it a few hours later.