Reused yeast cake

[manson81]

Well I can't find my original post on this topic (on my phone so couldn't really find it in my search) but had posted that I was going to pitch and Irish red on top of the previous Irish reds yeast cake.

A lot of you said that it's not going to develop the same flavours etc as if I pitched either new yeast, or took some of the slurry and repitched that.

Just tasting the beer now and I can definitely agree that a lot of the flavours have not developed as suggested. It's still a perfectly drinkable beer, but yeah, there's just something missing!

All good though, I'm not disappointed that I tried it, but doubt I'll do it again.

Just my feedback on the result...

 

[storeboughtcheeseburgers]

Get into rinsing yeast: http://aussiehomebrewer.com/topic/55409-rinsing-yeast-in-pictures/

I don't know if I'll ever do a slurry direct pitch, read too many horror stories.. one guy said his fermenter infected the next 3 brews eek. So at least you got something drinkable out of it.

Man Irish Red sounds nice, what recipe did you use?

 

[Yeastfridge]

I'll usually chuck in about a 200ml of slurry into the next batch if I'm bottling/brewing on the same day, enough - but not too much - fresh yeast.

 

[dent]

I don't know if I'll ever do a slurry direct pitch, read too many horror stories.. one guy said his fermenter infected the next 3 brews eek.

How is it more likely to get infected from a direct pitch than with washing the yeast with water? I'd say less handling, the better.

 

[thedragon]

I pitch on to a yeast cake when it suits me.

Only ever for similar styles, but I've not noticed any issues.

The reason I do it is for the time saving.

I was quite wary the first time given the potential to waste a 5hr brew day for a 20 minute time saving cleaning the fermenter, however it' has worked well for me. I will continue to do it from time to time.

 

[StalkingWilbur]

I pitched a porter on a brown ale yeast cake recently, the best brew I've ever done.

 

[MastersBrewery]

when you massively over pitch any yeast, you will strip out flavour, I note a lot talk with wyeast 3068, repitching not giving the same results even at second gen. 150-200ml of slurry should be about right.

Regarding infections there's plenty of good info out there to enable the brewer to simply wash and reuse, split and store( for years), and to go all the way to culturing with plates and slants. With any yeast handling sanitation, in some cases sterilization practices must be sound.

MB

 

[dent]

Infectionwise the processes of yeast washing (with water) and splitting are neutral - there is nothing about the process that will decrease the likelihood of an infection taking hold in your next ferment. If, however, you're getting it down to a single colony on a petri dish you have a reasonably good chance there is no contamination. Then again, since you're starting up again from such a small sample, your processes must be excellent to grow it back up again cleanly.

Here is a good list which runs down the infection reducing aspects, or lack thereof, of several yeast washing solutions.

I've got some sodium chlorite but I still haven't gotten around to giving it a shot.

 

[storeboughtcheeseburgers]

How is it more likely to get infected from a direct pitch than with washing the yeast with water? I'd say less handling, the better.

Yeast doesn't eat all the bacteria unless it is above 2% ABV, which is why a lot of people step up with their starters and I think yeast rinsing and starting with a smaller amount of yeast is better.. I start in 300ml and raise to 1.5-2L gradually over around 3-4 days.

Its a lot easier to get up to that 2% mark with a small amount of wort than a massive full batch, meaning more bacteria growth.

 

[dent]

Huh? Yeast doesn't eat bacteria. It does alter the pH a bit, which some bacteria do not prefer, and consume nutrients that bacteria could use. I've never heard of this 2% ABV business.

 

[storeboughtcheeseburgers]

Huh? Yeast doesn't eat bacteria. It does alter the pH a bit, which some bacteria do not prefer, and consume nutrients that bacteria could use. I've never heard of this 2% ABV business.

It doesn't eat the bacteria, but if you pitch a different batch into a yeast cake, the yeast will be shocked and allow for more bacteria growth, moreso if there is some residual wort in the trub. By eating the bacteria I mean it reduces it.

The process of making a starter is to train yeast and by stepping up you make it more viable and more healthy yeast.

The issue I see with pitching direct on a slurry is the timing.. it will take a while for the yeast to adjust to the new wort and allow more time for bacteria to grow. If it was the same wort cubed it could be OK, but there are also advantages to starters such as cold crashing, where the yeast settles, some dies off and creates proteins to start more naturally.

 

[storeboughtcheeseburgers]

Also, the 2% is the estimated level at which the bacteria stops to grow.

 

[storeboughtcheeseburgers]

I read about the 2% thing here - post 6

 

[mosto]

With regards to the OP, the way I understand it, is you need your yeast to do a bit of work, but not too much. The more the yeast works the more esters and flavours they throw off. Underpitch, and you work them too much and get unwanted flavours. Overpitch, and you don't work them enough so they produce very little flavour. Get the balance right and you get the exact result you're after from your yeast.

With some neutral yeasts, like US05, pitching onto the yeast cake may not be as much of an issue as the yeast doesn't contribute a great deal of flavour anyway. However pitching onto a whole yeast cake for a yeast dominated beer, such as hefeweizen, isn't going to give you what you're after from that yeast strain.

 

[dent]

I appreciate your clarifications of your previous post, cheeseburgers.

. it will take a while for the yeast to adjust to the new wort and allow more time for bacteria to grow.

I really don't find the yeast is at all slow when used as slurry directly from a previous batch. In fact, that is the condition I find the active ferment commencing the most quickly.

I'm not convinced cold crashing to create dead yeast for the others to eat is a good concept. I wouldn't be surprised if that actually happened, you end up with autolysis type flavours as a result.

I wouldn't advocate putting a fresh batch of wort right over the top of a whole yeast cake as the ideal practice - but I don't think there is anything majorly wrong with using a portion of this yeast cake directly with no further treatment. Acid washing or ClO2 washing would be an improvement over this.

 

[Goose]

I appreciate your clarifications of your previous post, cheeseburgers.


I wouldn't advocate putting a fresh batch of wort right over the top of a whole yeast cake as the ideal practice - but I don't think there is anything majorly wrong with using a portion of this yeast cake directly with no further treatment. Acid washing or ClO2 washing would be an improvement over this.

I ferment in a stainless modded sankey keg (sabco jobby) with an adjustable drawoff tube (see below). When its turned vertical, it will allow most of the yeastcake to be pumped out using CO2 pressure after the beer is racked, but the bottom of the vessel has a dome shape on which settles a layer of yeast. I then pump in the next batch over this yeast layer.

My theory is that the most active yeast are at the surface of the cake and that that should be left behind after I pump out from the bottom. The fermenter remains closed at all times.

I am still experimenting but have repeated this 4 times without apparent deterioration in beer quality... so far.

It saves me yeast but most importantly saves me cleaning the fermenter after each batch.... these things are heavy and a bitch to clean properly. I have been criticised for this method, and referred to what a fermenter looks like after a batch and asked why I would ever wish to pump a fresh clean batch of wort into something that looks like this. What gives me peace of mind is that the system is completely closed from the moment I pitch the yeast into the first batch....

Comments welcome.

 

[storeboughtcheeseburgers]

I appreciate your clarifications of your previous post, cheeseburgers.


I really don't find the yeast is at all slow when used as slurry directly from a previous batch. In fact, that is the condition I find the active ferment commencing the most quickly.

I'm not convinced cold crashing to create dead yeast for the others to eat is a good concept. I wouldn't be surprised if that actually happened, you end up with autolysis type flavours as a result.

I wouldn't advocate putting a fresh batch of wort right over the top of a whole yeast cake as the ideal practice - but I don't think there is anything majorly wrong with using a portion of this yeast cake directly with no further treatment. Acid washing or ClO2 washing would be an improvement over this.

No Problems.

I see no reason why the same strain shouldn't be added to a slurry... Just for me (as a personal preference), I like to have a bit of idea about how much yeast I'm pitching.. For example, if its a big beer, I'd want a high krausen, high volume pitch that was built up in steps pitched in its entirety. But if it is a smaller beer, 24hrs for a starter should suffice where I would cold crash and just pitch the yeast only.

Rinsing yeast IMO is a good option to stockpile yeasts.. I think for yeasts where its hard to come by (in LHBS) or elsewhere, rinsing is an appropriate practice.. particularly if you are fond of a certain strain and its performance.

Also, if you are not brewing a similar beer and have slurry, I figure its better to collect some of the yeast and store than turf the lot.

Rinsing is time consuming and finicky but I find it has its purpose (at least for one reuse)

 

[dent]

I ferment in a stainless modded sankey keg (sabco jobby) with an adjustable drawoff tube (see below). When its turned vertical, it will allow most of the yeastcake to be pumped out using CO2 pressure after the beer is racked, but the bottom of the vessel has a dome shape on which settles a layer of yeast. I then pump in the next batch over this yeast layer.

Yeah I use a similar thing, but without the fancy super duper adjustable tube - I just trimmed 35mm or so off the end of the dip tube. I figure once I've tipped out the cake, whatever is left glued to the sides is about right

 

[Goose]

Yeah I use a similar thing, but without the fancy super duper adjustable tube - I just trimmed 35mm or so off the end of the dip tube. I figure once I've tipped out the cake, whatever is left glued to the sides is about right

yep, it definitely works. The only bit that concerns me is the possible effect of the grunge that tends to accumulate and stick on the fermenter walls, mainly around the rim of where the krausen as been. Because this sits in the first batch anyway , I am trusting that it is inert enough not to affect the second and beyond ferments... :mellow: seems ok so far.

 

[Vini2ton]

Don't ya just hate show-offs.