Using "yeast cake"?

[brants77]

I have a batch of NB's Lefse Blond in my fermenter right now & am contemplating using the yeast left in the bottom after bottling for a second brew. Was planning a fairly high gravity over hopped Belgian wheat/Trippel.

Is this feasable? can I simply pour cooled wort directly on to "cake"? Think I saw Jake doing somthing like this a few eps of Brewing TV ago.

Thanks in advance for any help. . .

 

[jvp1]

Yeah, do it up. You might try "washing" the stuff first.

https://www.homebrewtalk.com/f163/yeast-washing-illustrated-41768/

 

[brants77]

Sweet! Thanks Man! Hadn"t even heard of "washing" before, I'm gonna start saving yeast for sure.

 

[jvp1]

I haven't bothered to yet, but it's definitely a good idea, and can save a few bucks here and there. I've read a few sites that recommend against using several generations of yeast (ie, using a yeast from a beer that you brewed from a washed yeast that you obtained from another beer you previously brewed, etc) and that suggest future beers may inherit some of the characteristics of the previous beer from the washed yeast, but nothing too extensive.

 

[dbhokie]

It can save it, but if you use the whole cake (especially for primary) it will be severe overpitching. From what I understand:

White labs says:

If the beer is overpitched, yeast do not grow though a complete growth cycle. This results in few new yeast cells, which makes for unhealthy yeast and low viability by the end of fermentation.

So I'd say your biggest primary concern is re-using the yeast again, and also if you are using yeast from primary there is more trub in it as well, and it may contribute flavors from your previous beer to your next. Using secondary yeast or washed yeast makes this a bit less of a concern, although I don't think it's that much of one as long as they are somewhat similar.

 

[Cranny04]

Mr Malty has a re-pitch option on the calculator...

This way you can use your yeast cake with out over pitching...

 

[solbes]

I've done this 3 times and had excellent results each time. I usually skim the yeast off of the top, trying to avoid the denser trub/break layer underneath. I add this to a large sanitized jar that's 1/3 full of boiled/cooled water. Shake and let settle for ~ 10 minutes. Pitch the slurry on top.

1) 1.048 Patersbier to 1.080 Tripel - Skimmed about half of the WY3787 yeast on top from PB and pitched to Tripel. Acitivity in 3 hours. Fermenter blew the lid about 18 hours in. Finished nice and dry, ended up really great.

2) 1.051 Pale Ale to 1.064 Bells 2H clone - Skimmed about 1/4 of the Bells yeast on Top and pitched to Two Hearted clone. Activity in 4 hours. One of my favorite brews to date.

3) 1.050 Porter to 1.102 Russian Imperial Stout - Skimmed all of the Bells yeast on top and pitched to bucket. Activity in 3.5 hours. In progress, but I checked the gravity 6 days into primary fermentation and it's already down to 1.029, around 5-10 points higher than where I had hoped it would finish. Still slowly cranking away. Hydrometer sample tasted pretty decent actually.

 

[brants77]

Thanks for the replys. solbes, your #1 example is fairly close to what I'm planning, the cake is in a 6 gallon glass carboy, to skim the yeast should I just swirl & pour it into a jar leaving thicker trub?

So pretty much agreed that just pouring wort onto whole cake = overpitching?

 

[bk0]

So pretty much agreed that just pouring wort onto whole cake = overpitching?

I've just pitched the wort right on top of the old cake. Works fine.

 

[Skarekrough]

I've just pitched the wort right on top of the old cake. Works fine.

I've done this as well and had good results.

 

[dbhokie]

It will be an overpitch, if it is the whole primary cake, this doesn't have as many negative effects as underpitch, your beer will be fine, it may lead to less viable yeast if you want to reuse them after this batch.

If you do rack to secondary (a lot don't), I usually (If I am pitching straight onto a cake), pitch onto the secondary cake (there's a lot less trub and other undesirables in there as well).

Mr. Malty has a convenient re-pitching calculator to avoid overpitching should you wish to.

Or you can pitch onto the primary and quite probably be happy with the end result. Just be however anally retentive you want to be I suppose.

 

[solbes]

To brandts, I use a bucket for primary so have never had to swirl. I guess in concept it sounds like the best thing to do.

Be careful using yeast from a secondary. Yes there is no trub to deal with but you are A) using yeast that is likely more stressed and less viable and B) selecting those yeast cells that are less flocculent. You may have a hard time getting the beer to clear. Just some warnings that I read from others here.

 

[mattmcl]

I always pour right on the old cake. BE CAREFUL with a high grav beer! Pitching that much food onto that much cake will definitely require a blowoff tube. Ask me how I know.

 

[brants77]

Blowoff tube, cool. Should be bottling the blond next weekend & have ingredients for trippel, guess I could do bottling & brew day next Saturday. Big beer day!

 

[william_shakes_beer]

Pitching on a cake generally works well going from light to dark brews but not the other way around. If you usually do starters and have a stir plate you can also harvest yeast samples from your starter. That's what I do, so the yeast I use for a new batch has never touched another beer.

 

[Malticulous]

You can probably get away with pitching a whole cake once. Use it twice and your likely going to run into some yeast health issues. A cake might have around 800 billion cells. Pitch that into 20L and the rate is 40 million/ml. Normal pitch rates are 5-20 million per milliliter. That's about a quarter to half cake into 20L. At that rate the yeast can bud 1-3 times. You will have a more healthy culture that could be re-pitched indefinitely. I normaly consider beers over 1.070 or so to be a dead end beer and dump the cake. I keep my yeast alive making normal gravity beers.

 

[bk0]

Seems all like speculation to me. Unless I hear about people actually experiencing off flavors or yeast health problems, I will continue using cakes as-is.

The main issue I've run into is that after a few consecutive batches the fermenter gets very dirty and crusted with old krausen, so after 2-3 I like to clean it out and start fresh again.

 

[hogwash]

I would go for it. You'll need lots of yeast to dry out the Tripel.

 

[brants77]

Good call on the blowoff tube, brewed last night & it's going crazy! OG was almost 1.090, by far the biggest beer I've ever made.