quick reuse yeast cake question

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bitteral

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Just bottled a batch today, and am in the midst of brewing another. If I want to reuse the yeast cake in my primary fermenter, do I just leave it there, with the gunk around the top from the last batch, and pour the new wort/water on top of it?

Or do I need to move the yeast cake into a newly cleaned fermenter?

TIA
 
Leave it be and pour wort on top, the results will be explosive. Seriously you'll have the most vigorous fermentation you've ever had and it will start up in a hour or two. Attach a blow-off tube not an airlock unless you like cleaning up messes.

My Celebration IPA was dumped onto a 1056 cake and it turned out wonderful.
 
Thanks. I'm going to give it a try. It will be less than 3 hours from the time emptied the beer from the primary til the time I'm going to pour in the new wort (less than an hour from now). I left just a small amount of beer over the yeast cake, probably like a 1/4 inch and covered the top with plastic in the meantime.
 
Help!

Its been about 10 hours since I put the new wort/water over the old yeast cake, and I see no activity. No bubble from the blow-off tube, and I briefly opened the fermenter to peak in and saw no activity.

Should I wait a while longer, or pitch some new yeast?
 
bitteral said:
Just bottled a batch today, and am in the midst of brewing another. If I want to reuse the yeast cake in my primary fermenter, do I just leave it there, with the gunk around the top from the last batch, and pour the new wort/water on top of it?

Or do I need to move the yeast cake into a newly cleaned fermenter?

TIA
Click to expand...
You didn't do a secondary?

Did you pour hot wort on the cake? That would shock the yeast something fierce.
 
HB, I had not used a secondary, just 19 days in a primary. (Haven't yet bought a carboy for secondary, and have been doing ok with primary only so far--- I've only brewed 4 batches to date.)

Wort and water and old yeast cake were all at about 70F, probably withing a degree or two.

I did not pour in the wort to rigorously, but did pour the water on top fairly vigorously. I stirred the batch up, but didn't make any attempt to stir up the yeast from the bottom.
 
Pouring on top of a yeast cake doesn't mean it'll take off in quick.

I've done this many times and it still takes around 16-24 hours.

It will work though, have patience.
 
Thanks. Glad to hear that. Now I'll feel comfortable to wait it out for the rest of the day. 11:30pm will be the 24 hour mark.

I'll post the result either way.
 
OK, I was just asking those questions for clarity.

Make sure you stir the yeast up off the bottom next time. It was probably packed a little. If the yeast had been more in suspension then it may have taken off faster. :D
 
I'd say pitching on the cake requires the least amount of aeration out of all pitching methods due to the extremely high number of already viable yeast cells. I wouldn't want it completely devoid of O2, but just a little is good enough. My opinion only.
 
Just a note that fermentation is going fine now. After 24 hours, I still did not see any bubbles. I decided to swirl the bucket around then check one final time in the morning. Within minutes I was getting a steady stream of bubbles.

This has happened to me two times: got impatient with no bubbling after 24 hours, swirled the bucket around, and minutes later regular stream of bubbles. I guess that the fermentation was in progress, and my swirling precipitated the release of C02 from the wort, which then continued on. Looks like I should be learning a lesson in patience.

Thanks to all for the comments/help.
 
Well, I went away for the weekend, and when I returned, there is still on-going fermentation, though at a lower rate of course. But when I took a whiff of the canning jar where my blow-off tube is bubbling, the odor was quite different from what I've smelled from the other batches I've brewed --- the odor was a very strong citrus flavor, like grapefruit.

I'll probably just wait this out a couple of weeks until I'm ready to bottle and find out what is really going on then. But in the meantime, is this a bad sign? Any chance that infection would cause such an odor? I worry since I did open the fermenter bucket a couple of times early in the process, which I never did before.

I should note also that this is the first time that I've used a blow-off tube. In previous batches, I used the air lock, and probably the odor was the gas emitted directly from the bucket. In this case, the gas is going into a jar half full of water, so I wonder if the water itself, somehow affected by the gas, is giving the odor?

I know this is an unusual question, but...
 
In retrospect, my last post seems like a really stupid question. Sorry. Who knows how well the canning jar was cleaned and what had been in it.

I've replaced the blow-off tube setup with an airlock. I can't detect any strange odor at this point.
 
bitteral said:
In retrospect, my last post seems like a really stupid question. Sorry. Who knows how well the canning jar was cleaned and what had been in it.

I've replaced the blow-off tube setup with an airlock. I can't detect any strange odor at this point.
Click to expand...
If you are going to use a blowoff tube then the tube and the container you blow off into should be sanitized. And it is a good idea to use a sanitizer solution in the blowoff container.
However citrus flavors/aromas are common hop flavors/aromas. Did this beer have more late hop additions or different hop varieties? That may be your citrus aroma.
Craig
 
Whoa... whoa.... you just pour wort onto the remains of an emptied (except for the trube) primary?

Don't you then introduce your wort to the undesireable stuff that settled out of your last batch in addition to the yeast?
 
San Jose State University said:
Whoa... whoa.... you just pour wort onto the remains of an emptied (except for the trube) primary?

Don't you then introduce your wort to the undesireable stuff that settled out of your last batch in addition to the yeast?
Click to expand...

it will all settle out again.

I have reused yeast cakes two times now, and after draining the wort into the primary, I shook the hell out of it to aerate. I have had unbelievably active fermentation within an hour or two, and have finished fermentation 24-48 hours later...my most recent was a high gravity milk stout (1.079) onto a WLP004 irish ale yeast cake from a irish red sort of beer...24 hours after the SG is at 1.024 and it is still going....not bad!
 
Want to hear a secret? You can just plug in your blow off tube, tie it in a very loose half-hitch knot, and not use any liquid in the blow off bottle at all! I usually put some water in there at the end of fermentation so I can hear the bubbling to determine when to rack.

Others attest they have to have a sanitary laboratory jar with 200 proof liquor but I think this is a waste of booze.
 
CBBaron said:
If you are going to use a blowoff tube then the tube and the container you blow off into should be sanitized. And it is a good idea to use a sanitizer solution in the blowoff container.
However citrus flavors/aromas are common hop flavors/aromas. Did this beer have more late hop additions or different hop varieties? That may be your citrus aroma.
Craig
Click to expand...

The blowoff tube I used was sanitized and long (more than 4 feet), and the container was clean but not sanitized, and filled with tap water. Because of the long length of the tube, I hope that I'm safe this time. But thanks for the advice --- I'll be sure to use it next time.
 
ColoradoXJ13 said:
it will all settle out again.

I have reused yeast cakes two times now, and after draining the wort into the primary, I shook the hell out of it to aerate. QUOTE]

Just a note that I saw in Palmer's book that the stuff clinging to the sides of your fermenter can impart a strong bitter flavor if it is mixed in with a new batch. So if you reuse the yeast cake and shake or stir it to the point that the stuff on the sides mixes into your wort, it may result in a very bitter beer. I have no direct knowledge of that myself ... just passing along what I read. I guess I'll see for myself when this new batch is done.
Click to expand...
 
bitteral said:
ColoradoXJ13 said:
it will all settle out again.

I have reused yeast cakes two times now, and after draining the wort into the primary, I shook the hell out of it to aerate. QUOTE]

Just a note that I saw in Palmer's book that the stuff clinging to the sides of your fermenter can impart a strong bitter flavor if it is mixed in with a new batch. So if you reuse the yeast cake and shake or stir it to the point that the stuff on the sides mixes into your wort, it may result in a very bitter beer. I have no direct knowledge of that myself ... just passing along what I read. I guess I'll see for myself when this new batch is done.
Click to expand...

Yes, please let us know. I might try that myself soon if it works for you okay.
Click to expand...
 
San Jose State University said:
bitteral said:
Yes, please let us know. I might try that myself soon if it works for you okay.
Click to expand...

It doesn't taste bitter at all to me, but it is a chocolate milk stout that I racked on to a yeast cake from a very malty, lightly hopped Irish Red...
Click to expand...
 
I have only tried the yeast cake thing once so far (I am actually going to do it tomorrow with wheat yeast) but it was a wild fermentation to say the least, and a huge mess, because I didn't use a blowoff tube.

I would think that if you are really worried about the scum from the krausen, you could add some water to the trub and make a slurry, transfer that to a sanitized container of some sort, and then clean your fermentor and re add the yeast to the wort afterwards.
 
mjm76 said:
I would think that if you are really worried about the scum from the krausen, you could add some water to the trub and make a slurry, transfer that to a sanitized container of some sort, and then clean your fermentor and re add the yeast to the wort afterwards.
Click to expand...

That sounds like a good idea. Depending on how the current batch turns out, I may try it next time. Thanks.
 
Looks like this repitching on the yeast experiment worked out ok. Thanks to all for the advice along the way. Here are a couple of things I learned from the process:

1. Fermentation may not take off like a rocket. In my case, no bubbles in the airlock until about 24 hours. But in the end I had a good fermentation (1.061 to 1.016).

2. Remember when you go to rack from the primary (to secondary or bottling bucket) that you have twice as much yeast on the bottom. Take that into account when you plunge your racking cane into the primary. In my case, I was going directly from primary to bottling bucket, and I think accidentally siphoned up quite a bit of yeast. The ale was quite cloudy as I bottled it.
 
I want to reuse a cake I racked off the other day - but I have been busy so I took some out and washed it, put it in the fridge in case the remaining cake goes 'bad'

whats the longest you have held a cake in primary before reusing? I believe I repitched
on an old cake in a covered primary stored in my dark cool cellar a week or more with good results (ie it made beer not poison) any thoughts here?
 
chillHayze said:
Want to hear a secret? You can just plug in your blow off tube, tie it in a very loose half-hitch knot, and not use any liquid in the blow off bottle at all! I usually put some water in there at the end of fermentation so I can hear the bubbling to determine when to rack.

Others attest they have to have a sanitary laboratory jar with 200 proof liquor but I think this is a waste of booze.
Click to expand...
You know you are probably correct. I still think it is a good idea to sanitize the tube but its probably not a big deal, especially if you replace it with an air lock after some time. I've been watching Beer Nuts recently and many of the brewerys they are visiting use open fermentation vats. It did not appear that extreme measures were take to keep the rooms completely sanitary. My only concern with home brewing is that the environment of the fermenting may be less clean and a dirty blowoff tube sitting in water polluted with wort/krusen may provide a vector for an infection. Using a little idophor in the blowoff water should kill any possible problems. Probably over kill but it is cheap insurance.
Craig
 

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