Whats wrong with this idea?

[Dronfieldbrewer]

So we have all managed to salvage yeast from bottles. Carefully stepping up starters 10ml-100ml then 200ml and so on. So I have a supply of my own bottles with a smear of yeast on the bottom ready for when they are needed then it occurred to me....

I usually bung the first 19 litres of a brew into a cornelius keg, add finings to this. Gas it up then spend the next few weeks drinking it. Its constantly gassed so no way would any oxygen get to it. When its finished I usually get a load of dregs up and spend an hour or so cleaning it all out, throwing these away.....

Why not use these dregs and miss out a step or two??? So in the name of experimentation, my beautiful Topaz Pale finished yesterday. I've emptied this into a large sterilized jar and found that quite a bit of yeast has dropped out along with a bit of junk...Ive let it settle and poured off the top bit, in the meantime I've boiled up a litre of DME at 1035 and crash cooled it...

If this works, the advantages are:-

1) you know that the donor beer is free from infections as you have been tapping into it
2) a good few steps will be missed so less possibility of infection in new brew.

 

[LeithR]

That sounds perfectly sensible. It has been said on here previously that the best yeast is one which has been preserved under a nice thick layer of beer.

 

[robsan77]

For me, the question is whether the finings will cause any future issues.

 

[Dronfieldbrewer]

For me, the question is whether the finings will cause any future issues.

This occured to me too but when dragging it from a bottle, its been sat in finings for yonks in some wharehouse before I've been able to get my sweaty mits on it.
so a sizeable starter is the order of the day

 

[brewtim]

For me, the question is whether the finings will cause any future issues.

Finings don't kill yeast; they assist yeast in flocculating faster by clumping them them together so they drop to the bottom of the container faster under gravity clearing the beer faster, therefore fined yeast is still viable

I think recovering yeast from a corny is as good as recovering from a bottle, however the most viable ale yeast is to be had from top cropping during fermentation.

 

[pittsy]

I too agree with BrewTim :)

 

[Dronfieldbrewer]

Its bubbling nicely

 

[graysalchemy]

Yeast which is in a bottle or in a keg is the yeast which has taken the longest time to settle so by using that you are selecting for yeast which won't floculate. Continuing to do this will eventually produce a strain of yeast with poor flocculation. This is why the best yeast to use is top cropped as it has a greater genetic variation and is obviously viable. I always scoup out the yeast over the first few days and leave it in the fridge in a large sterilised tupperware tub until it is settled. This can be kept for a few weeks and pitched again if washed or split up and frozeen using glycrine.

:thumb: :thumb:

 

[Dronfieldbrewer]

Yeast which is in a bottle or in a keg is the yeast which has taken the longest time to settle so by using that you are selecting for yeast which won't floculate. Continuing to do this will eventually produce a strain of yeast with poor flocculation. This is why the best yeast to use is top cropped as it has a greater genetic variation and is obviously viable. I always scoup out the yeast over the first few days and leave it in the fridge in a large sterilised tupperware tub until it is settled. This can be kept for a few weeks and pitched again if washed or split up and frozeen using glycrine.

:thumb: :thumb:

Yep....not all the time, but was for this next brew and I left it too late to top crop

 

[Hoppy]

Hello All.

The yeast that takes longer to settle, ie the stuff still in suspension just at the end of a fermentation is the youngest (smallest and hence take longest to settle) cells that are highest in viability (this is because they have not budded yet).

You are not selecting a non-flocculating yeast that takes longest to settle from suspension. The yeast in suspension is on its way to the top, its just that when they were formed at the end of primary fermentation, there weren't enough amino-acids and zinc left in fermentation! If there was another day of fermentation to go these would rise to the top!

The cells at the very bottom are larger, old cells that are covered in budding scars, these have lower viability, as the scars prevent them replicating (in aerobic conditions before fermentation). Sluggish start to fermentation, then re-pitching, sound familiar?

What you need is the layer on the top of your sediment.

Nearly all the yeasts you have in home brew (and commercial) are now single strain yeasts that have VERY LITTLE GENETIC VARIATION (ie ideally NONE). No brews would EVER be consistent. This has nothing to do with viability. Yeast is not like an animal that needs to widen its gene pool.
Brewers that used to use multiple strain cultures have moved away from it, they had to keep re-culturing up as one strain becomes dominant over the others. If the strain that produces the best flavour is dominated by another, then the character of the beer will change, and you will have some unhappy folk if they have been drinking your beer for 25 years and know what to expect!

There is nothing wrong with your idea, obviously, commercially it is easier to remove a larger top layer and re-use (done it, resulting beer, 1st in class and 2nd in overall GBBF). The only folk who don't want you to is the producers of yeast.


Regards

Hoppy

 

[graysalchemy]

So you are saying that every time we pitch a yeast it undergoes no mutations due to environmental conditions and no natural selection and as a result there is absolutely no genetic drift?

 

[calumscott]

Nearly all the yeasts you have in home brew (and commercial) are now single strain yeasts that have VERY LITTLE GENETIC VARIATION (ie ideally NONE). No brews would EVER be consistent. This has nothing to do with viability. Yeast is not like an animal that needs to widen its gene pool.

That's got nothing to do with the yeast and everything to do with commercial brewers. Yeast, being a single celled, short lived, rapidly replicating (sexually and asexually) organism is very prone to genetic mutation given changes in it's environment. You keep the same yeast in the same environment perfectly, you're right, mutations are unlikely to gain the upper hand. Change the conditions though...

What you'll find most smaller scale commercial brewers doing is brewing on the trub. Yes, using the trub from the last beer to pitch directly on to. It's just part of a standard brewing cycle. Ten or 12 brews per "yeast cake" is not uncommon. Most will then re-culture from lab stock.

Hooky top-crop. They run 6 top crops before a full re-culture from lab stock of their yeast.

I can't say what the really big boys (your Fullers/Green Kings etc) do because I've never met one...

Anyway, much digression...

Assuming you have "house" yeast, the norm seems to be to bank a known good crop as your back stock, then either pitch cakes or top-crops for six to twelve cycles.

Why only a dozen?

Genetic drift of course.

 

[calumscott]

Genetic drift of course.

*cough* Sorry...

The *risk* of genetic drift of course...

 

[Hoppy]

There certainly shouldn't be, because the conditions in brewing are perfect for yeast, it has no need to drift. It has been naturally selected by US because each strain grows perfectly in beer, at the exclusion of less wanted contaminants.
Brewers are yeast harvesters, beer is the by-product!

That is how you get consistent beer! You'd be having off flavours every brew. You re-pitch, its the same strain each time. Yeast doesn't 'mate' and take on other attributes. Their progeny are in effect clones.

Yeast replicates by cell division, conservative replication of DNA, if there is anomaly they usually die, natural selection!

How have breweries stuck with the same strain for so many years? OK, these days many re-culture from slopes,but some are on 1000s of generations and the beer hasn't changed.

For yeast to mutate there has to be some pretty vile conditions, eg high concentration copper(causes elongation of cell), poor nutrition can cause yeast to sporulate, this is when it turns into an 'egg' and multiplies inside and makes numerous strains, then bursts, hoping at least one of its progeny will survive. Your brewery is long infected by then anyway, yeast being of little concern.

The way you crop, by definition, are collecting the yeast I mentioned to crop. It is just very hard to catch the slightly newer cells that have been produced in suspension because they haven't reached the top yet.

Hope this clarifies things
Kind regards
Hoppy

 

[graysalchemy]

So you are saying that every time a home brewer brews the wort chemistry is exactly the same, oxygenation levels are exactly the same and pitch temp are exactly the same. :wha:

I don't think so. Most of us use one yeast on various different recipes so conditions will vary from one brew to another in any case. And we simply don't measure all the variables so we can't possibly have a consistent environment or wort for the yeast every time.

And as for consistent results how many of us can honestly say that batches taste exactly the same.

Yes in an ideal environment perhaps you may be correct, but brewing 23l in a bucket in your garage are hardly going to give you the perfect lab conditions you are suggesting.

 

[calumscott]

Yeast replicates by cell division, conservative replication of DNA, if there is anomaly they usually die, natural selection!

conservativeISH replication.

The process of Mitosis (or budding in the case of lots of yeasts) includes a phase of DNA Recombination which produces subtle genetic variation through the swapping of parts of each chromosome before the cell splits, you don't get clones.

 

[dennisking]

The head brewer at the brewery I've been getting yeast from over the the last few years tells me all they do is top crop. Never wash or rinse. He has worked there over 3 years and was surprised when he started that they just continued to re-use and to his knowledge it's been that way for over 30 years. They have won the GGBF supreme champion award. But I can't make the same yeast go more than 2-3 generations having tried both top cropping and taking from the fermenter.

 

[Hoppy]

I appreciate my term clone was not an exactitude, but have you looked at how bad conditions need to be for sporulation?

My point was there should not be a noticeable drift, certainly over a few generations of home brew.

The reason a lot of breweries (I see Hook Norton mentioned) re-culture regularly, is they have a multiple strain culture that has 4 strains of 2:1:1 (If I remember correctly) that does drift in proportion, as a certain strain becomes dominant. I have first hand experience of this brewery and their culture.
I have isolated (with help, some years ago) 1 strain from this culture and is used in a dozen award winning breweries in the UK. One in particular has used this yeast for 6 years now, double brewing each day, with no ill effect and to much effect from an award point of view.
There are countless breweries with hardy yeast that have been used for many generations. They have mucked up with O2 levels, I have, doubled my O2 level during a 5000 litre transfer, tasted the same as the 2nd batch that afternoon, when tried 7 and 14 days later, the change is so small! I'm not denying change doesn't happen, we've made it happen in the labs, under pretty horrid conditions. The conditions mentioned by the OP and others would not really constitute poor conditions.

I'm well aware of what smaller brewers do Callumscott. I have visited over 600-700 UK brewers to date and well aware of their brewing practices.
Brewing on trub (dirty FV) really is not one of them, very, very few would do this. It really is not standard practice, not from 4 Million Hectolitre brewery or down to a 92 litre brewery and every size inbetween I have dealt with.

I doesn't matter that you don't have exactly the same environment each time. That why (presumably) we drink craft beer (i'm not opening a can of worms on this definition) because of 'character'. I would rather drink a beer that can vary a little, but not bland insipid products.
My closing point to the OP is (and was) that you have so many other variables to contend with a little mutation (which I said happens, to the tiniest degree anyway) is not worth worrying about.

Regards

Hoppy

 

[calumscott]

I'm well aware of what smaller brewers do Callumscott. I have visited over 600-700 UK brewers to date and well aware of their brewing practices.
Brewing on trub (dirty FV) really is not one of them, very, very few would do this. It really is not standard practice, not from 4 Million Hectolitre brewery or down to a 92 litre brewery and every size inbetween I have dealt with.

Well I know for a fact (first hand information) that at least one of the UK's award winning breweries does exactly this and he assured me that in today's ultra modern (closed, temperature controlled fermenter) breweries he is one of very many. He's the head brewer of quite a large craft brewery employing more than a dozen staff...

I would be very surprised if you hadn't spoke to him if you've visited 700 breweries.

EDIT: I suppose I should also point out that the process is not "dirty FV". The trub being pumped from a complete fermentation to the fresh wort in a sterile FV. Apologies if I insinuated otherwise.

 

[calumscott]

And anyway...

...just while we're here. The whole point of top cropping yeast is to get them early, in the first few replication cycles such as to limit any genetic drift when not re-culturing from lab-stock.

Those that settle towards the end of a (in homebrew land) 10-14 day ferment will be a few hundred generations away from those organisms which were first pitched. Top cropping in the first day of fermentation gives a usable number of cells only 10 - 20 generations (assuming a replication rate of 100 minutes).

Clearly the big boys get away with more as their cycles are shorter, 4 or 5 days for a typical ferment (72 generations roughly).

So if we take ten brews at 70 generations each that's 700 generations as a sensible (industry led) maximum per re-culture.

By top cropping that means you could theoretically push the culture to 35 brews without a noticeable drift.

There is of course, with breweries like Hooky, the fact that they open ferment which introduces the need to guard against wild strains polluting their cropped-on cultures, shortening the brew life of the culture and going back to the lab reduces this risk without having to change fundamentals of the brewery (i.e. they keep their open fermenters).