Using Yeast Cake

Hey all, I have been planning on reusing part of a yeast cake from a previous brew. I am planning on pulling the switch off in minimal time (racking off the old cake and pouring the new wort onto it). I have read a lot that pitching on an old yeast cake is considered overpitching. The cake is from a 1.067 steam style beer and I am pouring a 1.050 steam style beer onto it. (I want to re-do the Steam as my first is way out of the ABV guidelines for the style, its gunna be heavy but it will still be an awesome beer i think?)
MY question is, would it be advisable to scoop up only a cup or two of the old yeast cake, and pitch that into the new wort? I believe that would solve my overpitching problems, but I dont want to "Underpitch". Also, I definatly do not want to wash the yeast as I just dont have the time or patience. would tossing in 2 or 3 cups of the old yeast cake into a new and clean primary suffice??
Thanks a lot for the help guys! have a great day!

I have poured the new brew on top of the complete yeast cake from a previous brew without any ill effects. You will want a blow off tube though.

I think you'll be fine pitching onto the old yeast cake. It's hard for a homebrewer to overpitch. It's good you are doing the same style though, that way it won't matter about some crossover between the two.

Some would say that the yeast is too stressed by a 1.067 brew but you should have plenty of healthy yeast left over to do well on your next brew.

I actually do that fairly often. I take a spoon and a beer glass and scoop out 6 or 8 oz. of trub and add that when I pitch my yeast. Be ready for a fast ferment, and I would definetaly use a blow off hose.

It will be overpitching, however over pitching does not guarantee off flavors.

but you do need to keep tabs on it the first day or so. fermentation will be damn near explosive, even a 5 gal batch in a 7 gallon bucket can blow krausen out the airlock, or pop the lid off.

I only reduce the cake if it is more than 2 quarts. And that is strictly because of the location of the faucets in my fermenters, I don't want too much trub.

Generally you pitch a higher gravity wort on a smaller wort but I don't think it will make a great difference. I lost a 1\2 gallon of wort when I did this once because it was blowing off so explosively.

I pitched my milk stout directly onto the yeast cake of a porter and it turned out to be the best brew I think I've ever made. It did take off like a rocket, though.

I'm going to do this for my next batch, and all the advice I've gotten from here is that you need to go "darker" for the second batch...otherwise, they say, you'll get the flavors of the previous batch. Ie. you wouldn't want to try to brew a pale ale on top of a yest cake used for a stout.

Blender

"Generally you pitch a higher gravity wort on a smaller wort but I don't think it will make a great difference. I lost a 1\2 gallon of wort when I did this once because it was blowing off so explosively"

I have a 1.052 on deck now and I am planing a 1.075, ? this would work on top of
the yeast cake from the 1.052?

Last night I breweed up a beer similar to Edwort's Haus Pale Ale. I added a coffee cup full of trub from a beer I named Dark & Hoppy Honey. The Dark & Hoppy Honey had a half pound of dark Caro 3 and a half pound of Crystal 120 and it was hopped with chinook. Last nights batch was two row, crystal 40 and viena hopped with cascade. I used a new pack of Nottingham also. I don't care if the dark trub flavors carry over to beer #2 a little. I only added about 6 ounces of trub. I will see if this beer is as clear as I expect it to be..... (in a month or so)

I'm confused about "stressed" yeast. Isn't it simply reproducing? Wouldn't the dead yeast be the stressed yeast, and the newly created yeast still be fresh? How do places like white labs generate yeast for sale, if not by feeding and reproducing a small amount of yeast?

If you pitch on a yeastcake USE A BLOW OFF TUBE!!!

I did a PM brown ale yesterday and racked it onto a yeastcake of safale US 50 from and amber I brewed....Luckily I had read enough advice on here to put a blow off tube on it rather than an airlock....

As I as leaving for work this morning I heard a strange rumbling sound emenating from my brew closet....I peaked in to see all manner of gunk in the bottom of the conatiner of sanitizer that the hose sat it...and huge bubbles breaking forth.... It is the most active fermentation I have ever seen.

I like to take the tip off my racking cane, dip it into the yeast cake while the beer is still in there, and siphon off a cup or two of yeast off the bottom into my new fermenter/new wort.

This way I don't have to rush my first beer just to get some yeast for a second beer. Plus I don't over pitch, and I can use that orignal yeast cake for future batches.

Could you do this with lagers also?If so,at what stage?I usually go a week or two at around 66 degrees then go cold(30-40)for a month before i keg.
Cheers

Could you pitch onto the sediment from a secondary instead of a primary as long as you didn't dry hop? I would suspect the yeast is still viable since you are using some of hte buggers to carb bottles.

I like BeirMuncher's idea as well.

Onescalerguy said:

Could you do this with lagers also?...

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Yep. I've done it before.

If you pour your wort on to the yeast, will that throw off your hydro readings?
(Assuming your wort is 2-3 gallons, and your adding water, like me) Would I need to mix in one vessel, take reading, then pour onto yeast cake?

Plan9 said:

If you pour your wort on to the yeast, will that throw off your hydro readings?
(Assuming your wort is 2-3 gallons, and your adding water, like me) Would I need to mix in one vessel, take reading, then pour onto yeast cake?

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If I'm racking onto a yeast cake I usually cool the pot, fill that with my top off water (I have a 5 gallon pot, so I fill to right up to the brim) stir it to mix the water, take my hydro reading there, then I use my auto siphon to transfer from my kettle into my fermenter.

You can also take a hydro of just the wort (undilluted) and use the dillution ratio calculator that most brewing software has to figure it with the additional 2-3 gallons of top off water.

I'm sure there's also a formula floating around that you can use to calculate if you don't have brewing software....

Plan9 said:

If you pour your wort on to the yeast, will that throw off your hydro readings?
(Assuming your wort is 2-3 gallons, and your adding water, like me) Would I need to mix in one vessel, take reading, then pour onto yeast cake?

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The yeast cake shouldn't throw off your SG.

i just racked onto a cake with no problems. the first beer in there was a barley wine and i racked that off to settle in the secondary, while i racked an IPA onto the same yeast cake. took off like a rocket but i never use a blow-off. i rack about 4.5 to 5 gallons when i brew and have never had the lid blow off or crap in the airlock. (knock on wood) i'll keep doing it like that until i do have a mess to clean up lol

I'm currently doing a Dunkelweizen. I started it last night and plan to leave it in primary the whole time and rack to my bottling bucket in 10 days or so. Could I simply make a 4.5 gallon Dunkel wort and pour it right on top of the trub once the old batch is gone? I'm trying to prevent needing to purchase $7 yeast (mostly Wyeast slap packs) for each batch. With that cost gone, my batch price could get below $30, making it an even more attractive "hobby" to my wife .

I got my fermenting bucket in a wine-making kit, and I think it is 7.8 gallons (a 6 gallon carboy fit inside it with room to spare), so would an airlock suffice?

Also, I'm a newbie (on my 5th batch now), so just checking but:

trub = yeast cake

Right?

Thanks!

The 'yeast cake' is comprised of yeast and trub. Trub is everything not yeast, like coagulated proteins and tannins, hops particles, and other nastiness.

For the record, pitching onto a yeast cake is hardly ever a good idea with beers which have esters as part of the flavor profile. Yes, it is possible to overpitch when homebrewing, and knocking out onto a yeast cake is virtually guaranteed to do that. One of the classic symptoms of overpitching is little to no ester production. Which makes it a terrible idea for Weizenbier of any kind.

Google the Mr Malty Pitching Rate Calculator and figure out how much yeast slurry you'll need to properly pitch your Dunkelweizen. Add 30% to that figure and harvest that much slurry from your fermenter into sanitized glass jam jars or something. Use it within seven days. Easy as pie, and it allows you to clean your fermenter.

Cheers!

Bob

Kegged a Vienna/Columbus SMaSH on Sat. and brewed a blonde that pitched right onto the yeast cake. Was the 3rd batch I've pitched onto previous yeast cake. No problems and the fermentation is off in a flash, ususally 3-6 hours.

OK, so now you've introduced a new vocabulary word: slurry.

Based on its definition - "a watery mixture of insoluble matter (as mud, lime, or plaster of paris)" - I'm guessing this is just a gathering of the "stuff/gunk/goo" at the bottom of the fermenting bucket when you rack your beer off? If so, how does this differ from "yeast cake?"

I'm not trying to be dense, but I DO understand that minor crappy practices can give a majorly crappy batch, so I want to be sure I get this right.

So, Teufel (nice name, BTW), what would YOU recommend I do?

Thanks for the different opinions!

Oh, and NQ3X, sorry for double posting. I just saw that you pretty much answered this question fully (although restating your answer here wouldn't disappoint me ) in the other thread.

Hope I didn't break the rules or anything!

Ok so I brewed an APA 4 weeks ago, 5 gal in a 6 gal BB. Tomorrow I'm brewing a 2.5 gal AG Oatmeal stout.

-Should I dump the wort onto the whole cake or should I siphon it off and then only pitch some.
-If so, how do I save the rest?
-And finally do I have to clean the BB or will I be fine taking standard sanitary precautions?

Its like making a 5 gallon starter and decanting the beer.

FYI, what I ended up doing was putting the cake+a little beer into a plastic pitcher and sticking it in the fridge for about an hour. A lot of trub, hops, and crap settled to the bottom. I poured all the top layer, presumably the healthy yeasties on top of my batch in the fermentor. I stuck the pitcher with the trub back in the fridge and let it settle a bit more overnight. I then poured what was floating into a sanitized bottle and capped it. Will the bottle be viable with a started say in a few months? The primary is bubbling away, but it took a good 18 hours to get going.

Question 1:
I have a Kolsch fermenting right now and I want to pitch an Altbier on top of the yeast cake after I transfer the Kolsch to secondary. How much time do I have after racking to pitch the Alt onto the yeast cake?

Question 2:
After racking the yeast cake temp will be about 60F. Do it need to warm it up to pitching temperature (70-75F) before I pitch the wort on top of it or can I just cool my wort to 60F and pitch it on the 60F yeast cake?

Oh , and if you're wondering, the Kolsch ferments at 60F.

citabria said:

Question 1:
I have a Kolsch fermenting right now and I want to pitch an Altbier on top of the yeast cake after I transfer the Kolsch to secondary. How much time do I have after racking to pitch the Alt onto the yeast cake?

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I prefer to do it right away, but as long as you keep it sanitary, there's no reason to leave it sitting for a few hours, or even a couple of days.

Question 2:
After racking the yeast cake temp will be about 60F. Do it need to warm it up to pitching temperature (70-75F) before I pitch the wort on top of it or can I just cool my wort to 60F and pitch it on the 60F yeast cake?

Oh , and if you're wondering, the Kolsch ferments at 60F.

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Cool and pitch at fermentation temperature, or even slightly below it. You only want to pitch warm if you don't pitch enough yeast, which is not the case when you use a yeast cake.

Over pitching can increase esters.
YEAST GROWTH - Danstar Premium Beer Yeasts

Would using the yeast from a Hefeweizen be okay for an Alt Bier?

Also, this is my first post. WOOT!

Probably not but a Dunkelweiss would be perfect.

Ok just to be clear. I'm going to be reusing a yeast cake here shortly and have a question. I'm not going to just pitch on top of the yeast cake. So my thought was after I rack the wort off the cake. Collect what is left in a container. Clean the Primary. Add the new wort. Aerate. Then pitch a portion of the yeast that is in the container (I’m not concerned with saving the rest.) Would pitching 1/2 of what is left be considered over pitching? Its just another 1.042 ale going on top of it.

thanks in advanced.

Half would be way overpitching. See MR. Malty, "Repitching from Slurry."
Mr Malty Pitching Rate Calculator
Use 2/3 cups.

hey thanks. although the "thin slurry and thick slurry" are kinda vauge, but it should give me a good idea.

thanks!

smakudwn said:

hey thanks. although the "thin slurry and thick slurry" are kinda vauge, but it should give me a good idea.

thanks!

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I can't remember which podcast it was, but there was a jamil podcast about repitching yeast where he mentions that the default setting for that thick-thin slider is about right for a yeast cake that's settled out in the fridge for several days to a week or so.

I think the viability rate drops off far too fast. Remember, the yeast companies have there hands in his site.