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Re-using a yeast cake?

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threeeight

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Jun 24, 2009
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Location
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Here's what I want to do:
1. Brew an ESB (og 1.047)
2. Pitch WLP005
3. Rack to secondary after 7-10 days.
4. Brew a Robust Porter (og 1.065) the same day the ESB goes into secondary, and rack the porter straight onto the WLP005 yeast cake from the ESB.

I've heard of other brewers doing this kind of thing with good results...is there anything special I need to do for this to go well? Can I literally just rack the ESB out and rack the Porter in, or are there more steps involved?

Thanks in advance for the help...
 
Yes you can and yes it's that easy. There are some who don't and never would repitch like this but I have done it many times with great success. You generally want to have your 2nd batch a darker style (which you do) and use a blow off tube - you have billions of hungry yeasties looking to chow down. I usually take a clean sponge soaked in starsan and wipe the krausen ring out of the top of the fermenter prior to pouring the 2nd wort in but other than that it's very straightforward and as simple as it sounds.
 
So is there any 'catch' to doing it this way short of possibly needing a blow off? Will fermenting too quickly cause issues? Will you lose a lot to blow off even with a 6.5 gallon fermenter and 5 gallon batches?

If this is as easy as it seems I'm going to have to start doing it...saves me $6 on a vial of yeast, and I know it's going to work...don't have to clean out the fermenter entirely either.

So going from a blonde ale to pale ale or IPA would be OK for this?
 
There isn't really a catch. For your particular situation it will be over pitching a bit, since your 2nd batch will only be 1.065. Another thing I do to re use my yeast is to rack it off into sanitized bottles and cap them for later. I usually fill up the bottle about half way. If you do it that way you can make that vial of yeast last a LONG time. People usually say not to use the old yeast after 3 months or so, but I've reused year old yeast w/no problems at all. And it feels good saving all that money!
 
Wow, thanks for all the help everybody! I generally do my primary fermentations in a 6.5 gallon carboy (5 gallon batch). Will I still need a blowoff tube?

I tend to err on the side of overpitching, and I've never needed a blowoff before...
 
From what I've read, overpitching can result in fewer esters or lazy yeast.

But for the most part, I think it is could be another home brew bogeyman. I've made the same recipes where I've pitched a smack pack in some, racked onto a used cake for some and a starter from washed yeast in several others. I've not noticed a difference or anything that makes me feel one is better than another. Keep in mind these were all pale ales. A lager or more delicate beer may be different. But I say RDWHAHB.
 
Did this today, and holy cow! I didn't really think I'd need a blowoff tube, but it's a good thing I peeked in on it about 5 hours after racking...the airlock was full of krausen, and when I pulled the stopper out, gooey gunk shot out onto the wall! Never again will I pitch onto a cake without using a blowoff!
 
I brewed a light ale and used WLP 007. It turned out great. When I bottled the light ale I also brewed a pale ale and used the yeast cake from the light ale. It worked great. It took 48 hours for the light ale to really get fermenting good and only a matter of a few hours for the pale ale to really churn. All in all I liked the process. Less cleaning, saves money, and I have heard that the 2nd and 3rd time you reuse yeast the better the beer gets. Not sure if it is a myth or not, but I see a lot of pros to reusing the yeast cake and not a lot of cons.

Just my 2 cents.
 
It was pointed out to me that it is not very difficult to sanitize a measuring cup, scoop the yeast needed (ala mrmalty.com) into a freshly sanitized ferementer, then rack onto it.


I was being lazy and racking unto cakes multiple times. It does work... but if proper pitching is so close and you can do it into a sanitized fermenter... why would I not, other than laziness?

By all means, repitch that yeast. I call your buddies and see if anyone needs a jar of whatever you are racking off of!
 
I'm assuming you can store yeast slurry in a sanitized sealed vessel in the fridge?

You sure can. There are great threads here on washing yeast. That is one way to do it. I have stored whole cakes in gallon glass bottles, topped with clean water. I also store slurry that I pump into pint jars with my autosiphon. mrmalty.com will let you pick a harvest date for your slurry to adjust the amount to pitch.

I have pitched 6 month old slurry with no problems. I have used washed yeast that was over a year old.

It is worth investigating and experimenting with. For my brewery, it is a win.:mug:
 
If your racking a new brew on existing yeast cake, without washing, do you care about any hop residue left over from the previous brew? Still starting out here, and I mostly do extract kits for now, but theres always alot of old hops sitting ontop of the cake.
 
Did this today, and holy cow! I didn't really think I'd need a blowoff tube, but it's a good thing I peeked in on it about 5 hours after racking...the airlock was full of krausen, and when I pulled the stopper out, gooey gunk shot out onto the wall! Never again will I pitch onto a cake without using a blowoff!

congrats you got your first yeast facial! :D
 
I've got an RIS with an apparently stuck fermentation. I've already pitched new yeast, but as many stated here, with little result. As soon as my IPA is done, I'm racking the stuck beer onto the IPA yeast cake. I've read this is an effective way to finish a stuck fermentation. Don't mean to hijack the thread; just a related aside.
 
I'm new to this forum, but I have been brewing for 20 years. It seems to me chefmike is giving good advice (in other words, his experience is mine). You could pitch right on top of your cake, but you are risking infection because of poor sanitation and you are probably overpitching (altering the way the yeast profile is supposed to unfold as it multiplies). I re-use yeast frequently. I even propogate it in my spare fridge (so technically, it is all re-used, except when I re-start with ur-yeast from another pack). But since I have the luxury of several carboys, I use a sanitary one each time I brew and either pitch from sanitary slurry (if I am brewing back-to-back) or from my home-made liquid yeast bottles (labeled, of course). Using enough (sanitary) yeast reduces chance of infection (because you get to beer faster) and reduces your cost per batch by as much as 25%. And if it makes you nervous enough to care more about sanitation, so much the better. (Did I mention sanitation?)
 
can you rack on to a (dry yeast) yeast cake?

yes. once pitched, it is all treated the same.

Still, as we said above, scoop out what you need and pitch into a clean fermenter. If you have to, you could always saitize a bowl, scoop the needed amount of slurry into there, cover it. Then wash your fermenter out (15 minutes tops?), pour in your yeast slurry and rack on to it.

Better safe then sorry. :rockin:
 
I've been doing a little research on this over the last couple of days and here is what I have found to be some good points to keep in mind...

-Generally you can count on there being 1.5billion yeast cells per mL of slurry
-Typically you want to pitch 200-400billion cells per 5g batch give or take a few billion, depending on the OG
-You want to pitch about twice as much yeast for a lager than you would an ale(not sure on the why just yet)
-Use The Mr.Malty calculator

I'm no longer liking the idea of pitching onto the whole cake. I'd rather start with a clean fermenter and the proper amount of slurry. There's too much other stuff in an entire cake and I really don't want my fresh batch sitting on it.
 
scoop out what you need and pitch into a clean fermenter. If you have to, you could always sanitize a bowl, scoop the needed amount of slurry into there, cover it. Then wash your fermenter out (15 minutes tops?), pour in your yeast slurry and rack on to it.

Better safe then sorry. :rockin:

That's what i did today and i've got "solid" fermentation about 4 hours after i pitched. Im not planning on a blow-off, but the yeasties might have different plans :D
 
You could pitch right on top of your cake, but you are risking infection because of poor sanitation and you are probably overpitching (altering the way the yeast profile is supposed to unfold as it multiplies).

Why are you risking infection because of poor sanitation? If it was sanitary when I put it in the fermenter, it should still be sanitary after it has fermented or you screwed up the sanitation in the first place.

In my experience, racking onto a full cake is fine if you are using a clean fermenting yeast such as WLP001 or Wyeast 1056, but if you are looking for certain esters such as when brewing belgians, you may want to start with a more precise pitch of yeast to develop those esters.
 
We are on our 13th generation of an original slappack of London 1968 with no problems whatsoever. We simple draw the yeast slurry from the bottom of the conicals, place it in Nalgeen bottles in the fridge until we're ready to pitch again. We've made Pales, IPA's, Browns, and Porters with this same batch of yeast and each tastes as good as the last..
 
Why are you risking infection because of poor sanitation? If it was sanitary when I put it in the fermenter, it should still be sanitary after it has fermented or you screwed up the sanitation in the first place.

Bingo! If you didn' sanitize well or have the beginnings of an infection how are you to tell until your first batch is ready? If you're uncertain about your sanitizing regimen then pitching on a cake is not recommended.
 
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