# Yeast died, gone off?



## trustyrusty (4/2/17)

Hi I used recovered yeast US 05 from a brew that I used the other. All was good with that result. Drinking well. With this new brew everything was clean. It started ok, bubbling.... Then 2 days later slowed and got this funny taste.Temperature has dropped so I think dead. This is about the 5 th time I haved used this yeast. Today it tastes awful, I cannot really explain the taste/smell ... off apples with vinegar? Any ideas? Thanks


----------



## MHB (4/2/17)

Infection!
If you recycle a yeast often enough its inevitable.
Mark


----------



## trustyrusty (4/2/17)

Thanks, funny thing is I tasted the yeast water before to check and it was ok..


----------



## trustyrusty (4/2/17)

If I made a starter would be better?


----------



## Weizguy (4/2/17)

MHB said:


> Infection!
> If you recycle a yeast often enough its inevitable.
> Mark


Only if due diligence is not a factor in your cultivation and brew sanitation methodology. But a big YES for real world brewing.



Trustyrusty said:


> If I made a starter would be better?


Not if the acetobacter is already in the initial yeast now. You should be aware that dried yeast may already have a small but insignificant amount of "bugs" in it, just due to the drying process. You increase that number of bugs by fermenting a batch of beer with the dried yeast, and further by re-pitching. THAT is inevitable.


----------



## manticle (4/2/17)

Sounds infected to me too.

Taste is a good indicator but not a perfect one - infection may have come from elsewhere and yeast re-use is coincidence OR contaminant numbers weren't yet high enough to reveal themselves at that point.

Whatever - vinegar and apples means bye bye.


----------



## Weizguy (4/2/17)

manticle said:


> Sounds infected to me too.
> 
> Taste is a good indicator but not a perfect one - infection may have come from elsewhere and yeast re-use is coincidence OR contaminant numbers weren't yet high enough to reveal themselves at that point.
> 
> Whatever - vinegar and apples means bye bye.


5th re-use of a dried yeast original. I'd say it's very likely, sad to say/ agree.


----------



## Jack of all biers (4/2/17)

Trustyrusty said:


> This is about the 5 th time I haved used this yeast. Today it tastes awful, I cannot really explain the taste/smell ... off apples with vinegar? Any ideas? Thanks


This happened to me years ago. It was the 4th or 5th time I re-used a yeast. It is the only time I have TASTED off flavours from an infection and the worst thing was I was splitting a double batch with a mate and his was the same. I felt really embarassed about that.

Since that brew, I made myself a golden rule. Never re-use a yeast (liquid or dried) more than 3 times. Usually, I only use once, but occasionally pitch onto yeast cakes when progressing from lager (helles/pils) to bock, then doppel bock (so 3 uses).

If you want to get more bang for your buck with yeasts, make a starter from the packet yeast and when its done split the starter into bottles and cap. Fridge them until you want to use the yeast, make a new starter, from the yeast from the bottom of the bottles (after decanting the liquid off) and use that to pitch.



Les the Weizguy said:


> a big YES for real world brewing.
> 
> Not if the acetobacter is already in the initial yeast now. You should be aware that dried yeast may already have a small but insignificant amount of "bugs" in it, just due to the drying process. You increase that number of bugs by fermenting a batch of beer with the dried yeast, and further by re-pitching. THAT is inevitable.


Les (or is it Brother Seth? :drinks: ) hit on the reason for my rule above. Real world brewing is exactly the reason.


----------



## trustyrusty (4/2/17)

Thanks I have about 10 bottles of yeast in the fridge, nervous to use now... is there a way to check? Interesting is only after a 4 or 5 uses? So liquid yeast would be better, it would never happen? 

How do the brewing companies like whiskey producers reuse yeast for 100 of years?


----------



## manticle (4/2/17)

Short of testing in a lab, you can either risk it or forget it. Maybe try a less important batch and see - if it turns out the same, you know it's cactus.

Personally, I'd wave goodbye as 1 pack = ~$5 and one infected full batch = more $ wasted plus time and equipment (which can also carry bugs, so more $).

Infection may have come from anywhere and there is no guarantee that reusing yeast from anywhere is risk free. It's just worth noting that dry yeast has a negligent amount of bacteria when fresh - if reused too often, those numbers increase beyond negligent.

As for commercials - any number of things is possible. Firstly their sanitation capabilities likely exceeds yours (and mine), secondly they will often have the means to accurately quantify and qualify contamination levels, thirdly they often have a pure culture from which they can multiply usable yeast (rather than reuse the same batch) and fourthly, in the case of distilleries, they further purify*.

*I'm not super au fait with distilling: currently only a connossieur rather than practitioner but the first fermented wash does not need to be as clean as fermented beer as far as I understand. Happy to be wrong on that last.


----------



## MHB (4/2/17)

Trustyrusty said:


> Thanks I have about 10 bottles of yeast in the fridge, nervous to use now... is there a way to check? Interesting is only after a 4 or 5 uses? So liquid yeast would be better, it would never happen?
> 
> How do the brewing companies like whiskey producers reuse yeast for 100 of years?


They go back to a single cell, and culture it up to a usable population, along the way it would be tested for taste and other performance factors before use.


----------



## Jack of all biers (5/2/17)

Trustyrusty said:


> Thanks I have about 10 bottles of yeast in the fridge, nervous to use now... is there a way to check?


10 bottles that are about to be used for their 5th time? or 10 bottles that were cultured from the fresh yeast pack? The way to check is do a small batch 2L or so, but really it is so much effort when you could buy a new pack for $5 or so.



Trustyrusty said:


> Interesting is only after a 4 or 5 uses? So liquid yeast would be better, it would never happen?


No. It will happen to liquid yeast in the home brewing environment or as Les put it, Real world brewing. Other bacteria can get into brews via the air that is in the environment or other means (eg using vinegar to clean equipment or not cleaning equipment throughly or not sanitizing equipment thoroughly etc, etc.)

The bacteria may not have started from the dried yeast, but could have gotten into your first, second, third or fourth brew from other means, where their numbers did not affect the taste, but their percentage of population were kept along with the yeast you stored from each batch. When you pitched into your fifth batch the bacteria that had multiplied over the previous brews had bred into a significant population whereby you could taste the vinegar flavours. That's one theory anyway.

The other theory is that the bacteria only got into your fifth brew. Either way, an infection got into a brew you made, which should show you that it could happen to any brew you do. This is why it is important to devise a system of yeast use that takes into account the environment you brew in so as to minimise the chances of allowing an infection in one beer becoming progressively worse over a few brews until you can taste it (it's a bit like playing Russian roulette, you eventually find the loaded chamber).


----------



## trustyrusty (6/2/17)

Hi I was thinking - is there way to of cultivating yeast before using the yeast in a brew. If I make say 4 or 5 batches from a yeast pack and then use those for brewing. If that makes sense...Like making starter, stepping up and then storing. That is only ever one use, maybe keep for one more brew but dump after two uses...
So getting about 10 brews from one yeast pack?


----------



## manticle (6/2/17)

Yes. There's some great tutorials on splitting packs. I'll see if I can find one.

Sanitation needs to be spot on.


----------



## manticle (6/2/17)

Start here: http://aussiehomebrewer.com/topic/67590-splitting-yeast-packs-in-pictures/


----------



## trustyrusty (6/2/17)

Thank you


----------



## Jack of all biers (6/2/17)

Trustyrusty said:


> Hi I was thinking - is there way to of cultivating yeast before using the yeast in a brew. If I make say 4 or 5 batches from a yeast pack and then use those for brewing. If that makes sense...Like making starter, stepping up and then storing. That is only ever one use, maybe keep for one more brew but dump after two uses...
> So getting about 10 brews from one yeast pack?


Um....


Jack of all biers said:


> If you want to get more bang for your buck with yeasts, make a starter from the packet yeast and when its done split the starter into bottles and cap. Fridge them until you want to use the yeast, make a new starter, from the yeast from the bottom of the bottles (after decanting the liquid off) and use that to pitch.


Kinda what I was getting at, but... 



manticle said:


> Start here: http://aussiehomebrewer.com/topic/67590-splitting-yeast-packs-in-pictures/


that thread is another take on it.


----------



## Rocker1986 (7/2/17)

I harvest yeast from yeast starters each time I make one. I could do the whole make a big one and split it into 5 or 6 jars, but I don't use the same yeast on every batch so the latter couple would probably die before they got a chance to be used, or at least be very low in viability which would mean more work by having to step them up once or twice. My basic process is to build the starter bigger than necessary, and once fermented pour the excess (well mixed up) into a mason jar and store this jar for next time, repeating the process each time with the yeast from the jar. Generally they're used again soon enough that I don't need to do a step up.

I went to 9 or 10 generations with US-05 until it started throwing awful phenolic type flavours rather than vinegar, so no infection but will limit it to 7 in future to be on the safe side. Conversely, I've been re-using a Wyeast 2001 smack pack since April of 2015 with this method which has yet to produce a shitty batch. Unfortunately I've lost track of the generations but it would be over 10. I'm also up to 6 gens on a 1469 pack, which is still going well. I have to figure my cleanliness and sanitation is good to be able to keep using them like this. B)


----------



## trustyrusty (7/2/17)

Rocker1986 said:


> I went to 9 or 10 generations with US-05 until it started throwing awful phenolic type flavours


When you say 9 or 10 generations - so you make a starter from the left from each starter... that is sort of what I was thinking because you are not taking yeast from a beer batch that had other ingredients in it , and had more chance of getting or starting an infection or 'bugs' that carry over to next batch. ( I have found dry hopping has caused a problem before with infection)..

Anyone know where you can buy those vials with the screw top that is in those pictures.
Thanks


----------



## Jack of all biers (7/2/17)

Scientific equipment shops (chemical retailers sometimes too), eBay, from memory some of the HBS like beer belly. On my phone so cant give you the links right now, but a quick google search will get you there.


----------



## Tony121 (7/2/17)

https://proscitech.com/?navaction=show_page&chapter=l&page=9


----------



## Rocker1986 (7/2/17)

Trustyrusty said:


> When you say 9 or 10 generations - so you make a starter from the left from each starter... that is sort of what I was thinking because you are not taking yeast from a beer batch that had other ingredients in it , and had more chance of getting or starting an infection or 'bugs' that carry over to next batch. ( I have found dry hopping has caused a problem before with infection)..
> 
> Anyone know where you can buy those vials with the screw top that is in those pictures.
> Thanks


Well, sort of... Say I have a fresh pack of yeast. I make a starter too big for the batch, pitch the pack of yeast (re-hydrated first if dried yeast) and then take the excess into a jar once it ferments and store this jar in the fridge, then pitch yeast in the starter itself into the batch wort. Next time I use that yeast, I simply do the same thing with the yeast in the jar from the last one, and then harvest the excess back into the same jar, obviously cleaning and sanitising the jar first. So yeah, the yeast is not harvested from batches of beer but from the yeast starters.


----------



## Jack of all biers (7/2/17)

Or if you don't want to buy hundreds or a thousand at a time
http://www.ebay.com.au/sch/i.html?_from=R40&_trksid=p2050601.m570.l2632.R2.TR12.TRC2.A0.H2.Xtest+tubes.TRS0&_nkw=test+tubes&_sacat=11815

Or
https://shop.beerbelly.com.au/sterile-petri-dishes-20-pack.html

Or
http://aimscientific.com.au/index.php?main_page=product_info&cPath=4_35&products_id=1177

I have an account with the last one and the screw capped test tubes range from $1.80 (100mmx12mm) up to $2.80 (180mmx18mm). These types of retailers are everywhere so you will find one more local to you.


----------



## Tony121 (7/2/17)

I got 50 x 50ml free standing tubes delivered from Proscitech thinking that would do me for years. 3 months in and am kicking myself for not ordering more and saving on delivery!


----------



## trustyrusty (8/2/17)

Thanks guys - I was wondering - does any one have the volumes LDM / Water + Yeast / SG FG to make a enough to throw in as yeast for the beer without making a starter, enough to brew. I am thinking I am going to save time and less chance of contamination without making another starter each time. Is that a good idea or have a I missed something? I have a yeast pack that is out of date that I might do a test on...

BTW does a starter have to used LDM or Malt or can you use sugar?

Thanks


----------



## manticle (8/2/17)

Don't use table sugar. Use malt.

There are various yeast calculators aroound but sufficient yeast amounts depend on beer type (lager needs around 2x ale or more), yeast freshness and wort gravity. So, like so many things - it depends.


----------



## trustyrusty (9/2/17)

Hi I watched a video online where someone at then end of a brew washed the trub with about 2 L of sanitzed water and made up 5 or so 500ml bottles which he stored. That would give him 5 batches of generation 1 yeast. The 500 ml of water would produce about an 2 inches of trub in the bottle which had enough yeast for another batch..Not a bad way to do it? Thoughts?
Thanks


----------



## manticle (9/2/17)

Yeast washing, acid rinsing. Threads on here about that too with some good detail.

Definitely worth looking at if you are serious about yeast reuse.

Also look at top cropping.


----------



## trustyrusty (19/2/17)

PS fermenter vessel tap may have been infected - so now not sure this is this was the issue.


----------

