Reusing Yeast Cake

[msehler]

I had a quick question regarding reusing the yeast cake. Last night I bottled an Irish Red (Northern Brewers) (it spent 1 day shy of 4 weeks in primary), followed by brewing an Amber (Autumn Amber from Midwest). The amber kit had dry yeast and the Red used Wyeast American Ale II, so I thought it (the Wyeast) would work rather well with the Amber INSTEAD of using the dry muntons yeast.

My question is this: everything I've read says the fermentations usually take off like a rocket when reusing yeast. I woke up this morning expecting it gurgling away and there was nothing...not a bubble (~9 hours).

How long should I wait before adding the dry yeast to get this fermenting? Any Idea on what may have caused the yeast to go dormant? Is there something I missed completely?

And don't worry...I will RDWHAHB...just making sure I'm not missing something.

 

[MalFet]

If you assume that your beer isn't fermenting because you don't see bubbles, you are liable to get yelled at around here. At 9 hours, I think it is far, far too early to make any assessments. Your yeast isn't dormant.

 

[tjpfeister]

I'm on my fourth yeast cake batch, and like the others it has yet to take off violently. I suspect the little guys are sleepy and the 8-12 hour lag I have been seeing is because they need to wake up. I have not had any rocket-batches, but they have all been solid 3-4 day primaries. No piddle-piddle-poop-poop out of the airlock if you catch my drift. I wish I could draw a graph on here to better explain what I have noticed.

That being said, I still start each one off with a blow off tube; just in case.

 

[GIusedtoBe]

I have always harvested or washed the yeast and kept it in mason jars for re-pitch into starters so i really do not know what you guys are talking about when are talking about using a yeast cake. Do you siphon off the beer and then pour the new wort right back in?

Last batch I did I poured all the yeast into a sanitized mason jar refrigerated for a week and then pitched it into a India Brown Ale Saturday night. This is WLP 001 and by Sun morn I had a nice krausen.

Regards,
Alan

 

[MalFet]

I have always harvested or washed the yeast and kept it in mason jars for re-pitch into starters so i really do not know what you guys are talking about when are talking about using a yeast cake. Do you siphon off the beer and then pour the new wort right back in?

I don't do it, but that is what people mean when they talk about pitching on a yeast cake. It's a fairly common practice.

 

[patrck17]

Assuming you didn't toss the new wort on there at too high of a temperature I think you will see it kickstart into action pretty soon. Other concern may be a leak in your fermenter seal. I've had entire batches go without me seeing a single bubble in the airlock. I traced it down to my rubber grommet not creating a seal with the plastic lid. I RTV'd the hell out of it and now I get a good airtight seal.

 

[tjpfeister]

Mine just started, approximately 16 hours later. Now, to be fair to this yeast, it was lager yeast that had been sitting in the bottom of a cold secondary for two months, so the fact that it woke back up and is going to work on my new steam beer makes me thrilled. Even if it did sorta take it's sweet time about it ;-)

I have always harvested or washed the yeast and kept it in mason jars for re-pitch into starters so i really do not know what you guys are talking about when are talking about using a yeast cake. Do you siphon off the beer and then pour the new wort right back in?

Yes, the practice at a rudimentary level is to just pour the beer on top. I don't like planning schedules that tight so I normally leave a bit of beer on top and slosh it into a slurry then store this in a mason jar. I'm not actually washing it, so I still consider it to be cake status.

 

[BlueMonkTrane]

There are many issues and problems about re-pitching onto a yeast cake or using a fresh slurry that I have found to be true. Yeast can be quite finicky. When re-pitching you must consider the OG of both the beers. Say for example, you brewed a BIG beer that finished with 10+ % abv, and the yeast cake has flocculated. In this case, the yeast, most strains, that is, are worn out and are conditioned to survive in that alcoholic environment. It's gonna be a high grav. yeast at that point IMO, better suited to beer brewed in high grav. styles and revitalized using a starter. The most efficient way to pitch on a yeast cake is from lower OG to higher OG. Consider that yeast are cultivated in low gavity environments, ~1.020, packaged and then are pitched onto higher gravity wort, where they are ready to go, not pooped out from a vigorous, alcoholic fermentation. But, thats not why yours is taking a long time because I dont think that your two beers have a huge difference in OGs, correct me if im wrong.
The yeast has probably taken a long time to start fermenting because they have been in primary for a long time and have fully flocculated, and the yeast strain is an American ale style, which are typically moderately to highly flocculant. When you want a faster ferment start, a good idea when pitching onto yeast cakes that have flocculated like yours may have is to somehow rouse the yeast and suspend them into the wort. Or brew and pitch on the yeast cake right after primary finishes, while the yeast is ready to go. That is how breweries typically cycle yeast cakes, but this requires frequent monitoring of gravities, and LOTS of brew days to keep the yeast going.
But, again it is a holistic view when looking at fermentation problems, alot of times it is not one singular mishap that makes the ripple but a combination of everything and all too much troubleshooting.

Happy Brewing

 

[GIusedtoBe]

Mine just started, approximately 16 hours later. Now, to be fair to this yeast, it was lager yeast that had been sitting in the bottom of a cold secondary for two months, so the fact that it woke back up and is going to work on my new steam beer makes me thrilled. Even if it did sorta take it's sweet time about it ;-)



Yes, the practice at a rudimentary level is to just pour the beer on top. I don't like planning schedules that tight so I normally leave a bit of beer on top and slosh it into a slurry then store this in a mason jar. I'm not actually washing it, so I still consider it to be cake status.

Well thats what I did but usually my brew sessions are farther apart so I need to wash and store the yeast and revitalize them in a starter. I've had yeasts refrigerated this way that have lasted over two years. Getting ready to try and resuscitate an old Bavarian lager and an old Wyeast 1056.

Have never had a stuck fermentation but then again 1.075 to 1.080 is about as high as I've ever gone.

Alan

 

[msehler]

For the record:
I understand no bubbles doesn't necessarily mean no fermentation, although I've never found that to be true

To clarify, I chilled the wort to ~70*F (my laser thermometer said about 76, my analog thermometer showed about 65*), and then poured the wort onto the yeast cake. It definitely stirred the yeast up and oxygenated the wort (I'm not gentile on this step).

The OGs should be almost identical (both around 1.050-1.055... don't know for sure because I don't have my brewbook here in front of me).

Lastly, I KNOW the fermentation started because I saw the bubbles This was ~10 hours later when I got home from work, so 19 hours after pitching. Thank you all for your help! Now I need to read up on "yeast cake saving" (washing and yeast starters seems like a lot more work)...that stuff gets expensive.

EDIT: oh yeah...and it's far from a violent fermentation, but pretty healthy none-the-less.

 

[tjpfeister]

Good to hear boss! FYI, the initial expenditure on an erlenmeyer flask will pay for itself quickly. I know my starters are small by comparison, but I typically work in ratio of 1/2 cup to 600mL water. (I know, crucify me for measuring DME by volume). But long story short is that each starter costs me about $1. Now if you take into consideration that a vial of white lab's yeast is around $8 at the LHBS, I can rapidly regain my $20 flask investment by propagating cultures of my favorite yeasts. But I'm rambling because I have a tummy full of whiskey and I digress... So I'm glad to hear your cake worked sir!

*Edit*
PS, I like the sarcastic winks about the airlock bubbles

 

[kmk1012]

Last time (the only time) I pitched directly onto a cake, the fermentation was the quickest and most violent that I'd ever had. It was pitched directly after the previous fermentation was complete.