Yeast Problems Using a Yorkshire Yeast Strain

[Brownster]

Hi All,
After three years and a good number of AG brews I have just had to tip a whole batch away as it became infected (first time) so I'm looking for advice on what went wrong and why.
The problem hinges around using a new yeast I hadn't tried before, now before I say anything else I blame myself for this and not the supplier, I suspect that somewhere along the line I have done something wrong.
I bought a vial of Yorkshire No.1 on an agar slant from Brewlabs and decided to split the culture up into a number of bottles. Following the advice on here I used some frozen wort I had stored, re-boiled for ten minutes, cooled to below 25C and introduced the yeast (500ml of wort). Now here's the first thing that I should cough to, I had trouble controlling the temperature as at the time the room was too cold at about 15C; I was using a wine makers heat mat to stand the yeast on. Through my sloppiness the temperature went too high for 24 hours, it was in the high 20's like 27C, fermenting like mad and then I tried to bring the temp. down by moving the wort further and further off the mat till it dropped to low 20's. After a couple of days I cultured up again by adding a litre of wort (boiled and cooled) using a demi john this time and again it fermented well but with the temperature controlled better at around the 22c mark. I allowed to ferment out for 5 days then split and stored in 4 x 500ml bottles in the fridge.

So that's the yeast background, now the first brew I did using one worked but with problems and I posted on here about it in a previous thread. I had cultured up one of the bottles first with 500ml, then 1ltr before draining off the bulk of the wort and tasting it which was lovely I have to say, and used to brew a TT Landlord. It stopped at 1022 as I went to bottle at 10 days and found out after getting all my bottles ready lol. Anyway I roused by stirring gently so as not to introduce any air, put a thermostatic heater in to replace the large heat mat it was on to control the temp. better (why I didn't do this in the first place I don't know) and it slowly got going a krausen of an inch appeared and it finished off, taking a total of 3 weeks from beginning to end. I was glad it made it and the beer tastes fine and unfortunately is going all too fast

Now to the disaster, I used another bottle of starter culture, stepped it up using the same process using frozen wort, 500ml for 2 days, 1ltr for 4 days before adding to a new brew (black sheep ale) using the thermostatic heater I took readings each day and was satisfied it stayed at 22C daily which I checked for about a week. At 2 weeks I took a SG reading to find it had stopped at 1022 as in the previous brew, the head had all but gone, it tasted fine with no off flavours but I noted a slightly stale or acidic odour on removing the beer lid. I decided to use a new culture to get it going and used a 500ml starter bottle (using 4 tbsp malt extract, 300ml water, boiled for 10 minutes and cooled) and got the culture growing for 2 days before pitching into the beer, rousing gently too in the hope that maybe the yeast present might get going too.
Four or five days later, total time 3 weeks, I took another SG reading and it was 1020 but it was infected, acetified, just awful, did the only decent thing and watered the garden with it; flowers are still alive which is something.

The way I see it there are a number of possibilities and I'm a bit stumped as to why this yeast has not fermented out without problems in the first instance and with disastrous consequences in the second.

Firstly I am thinking did over heating the yeast during the initial culturing up before storing cause problems, mutation or weakening of the yeast strain, is that likely or even possible?
Secondly did I grow the yeast cultures up enough before pitching and was the problem due to a lack of yeast cells to see the job through quickly?
Thirdly is it down to yeast type as mentioned in the Graham Wheeler book on Northern yeast strains (page 26 of BYOBRA) where it is stated "... Northern yeast does not particularly enjoy making alcohol and needs frequent rousing to maintain fermentation..." which goes on to suggest twice daily rousing to introduce more oxygen is required and further mentions the processes of a number of Northern Brewers ?
On this point I note that Brewlab do not give specific advice to rouse this yeast and on their general help notes advise against rousing after pitching.

Thanks,

Wayne.

[Wolfy]

Hi All,
The way I see it there are a number of possibilities and I'm a bit stumped as to why this yeast has not fermented out without problems in the first instance and with disastrous consequences in the second.

Firstly I am thinking did over heating the yeast during the initial culturing up before storing cause problems, mutation or weakening of the yeast strain, is that likely or even possible?
Secondly did I grow the yeast cultures up enough before pitching and was the problem due to a lack of yeast cells to see the job through quickly?
Thirdly is it down to yeast type as mentioned in the Graham Wheeler book on Northern yeast strains (page 26 of BYOBRA) where it is stated "... Northern yeast does not particularly enjoy making alcohol and needs frequent rousing to maintain fermentation..." which goes on to suggest twice daily rousing to introduce more oxygen is required and further mentions the processes of a number of Northern Brewers ?
On this point I note that Brewlab do not give specific advice to rouse this yeast and on their general help notes advise against rousing after pitching.

The obvious answer for why it didn't ferment out without problems - you have already answered yourself - is that you did not treat the yeast in a way it was used to, expected or needed in order to produce the beer you wanted.

Mid/high 20s is a fine to grow starters (the yeast can cope up to 37degC), but ideally the starter temp should be between 18 and 24degC. At warmer temps the yeast's metabolism will be a bit quicker and it will throw lots of flavors and esters but since you are growing yeast not making beer those things don't matter so much. However, too warm and the yeasts cells will be weaker, and too cool you get slower and less growth, and it seems you pushed your starter through both. What might be more an issue than the min/max temperature is how quickly you changed that temperature, thermal shock can cause the yeast to mutate and have other unwanted consequences, so when you put it on, or took it off the heat-mat it may have heated or cooled more quickly than the yeast were easily able to cope with.

I use a stir-plate, but a 1 to 1.5L starter seems like a resonable size to grow yeast for a UK-ale, so if your yeast were healthy and viable, that should not have been a problem.

While your experiences may have discouraged you from using this yeast ever again, I'd suggest that you use it one more time, but next time follow the advice from BYOBRA. On the page you reference, you'll see that breweries keep the yeast active by pumping it around on a frequent basis, so unlike other yeasts you may have used in the past, don't be afraid to thrash it around, really stir it in, or shake the fermentor to get the yeast and fermenting beer well mixed (up to twice per day for the duration of the fermentation as per BYOBRA) - since this is what the yeast is used to - don't worry about it being a different process to what you are used to. I'm not sure the book suggests the rousing process is about introducing more oxygen as much as it is to stop the yeast from being lazy and settling out before its job is done.

On a related note, I've found that BrewLabs "Sussex 1" yeast (which may well be related to the one you are using) also needs similar rousing and attention to get it to attenuate to the levels required.

[Oscar Brewer]

I've used Brewlabs Yorkshire 1 yeast a few times in the past and haven't found problems or needed to rouse or give additional areation during fermentation. This yeast shouldn't be confused with a "Yorkshire Square" strain such as the type used by Sam Smiths or Black Sheep which are highly flocculant and certainly require pump rousing during fermentaion, and I would think that it is these particular yeasts that Graham refers to in his book as "Northern Type." If you look at the Brewlab information sheet, Yorks 1 is marked as "medium flocculation" and it behaved well for me, fermenting a 1.039 beer down to 1.008 in about 5 days at 20 -21C. A couple of things to check; make sure you aerate the wort well before pitching of if you can't easily achieve this at least aerate the starter as as an alternative. A 1/4 - 1/2 teaspoon of a yeast nutrient such as Brupaks yeast-vit or Wyeast Nutrient added to the wort before pitching ( or at the end of the boil ) will do no harm at all and correct any nutrient defficencies in the wort. This yeast is very suitable for top-cropping if you wish to re-pitch and may need skimming near the end of the fermentation.

[Beer O'Clock]

I've used Brewlabs Yorkshire 1 yeast a few times in the past and haven't found problems or needed to rouse or give additional areation during fermentation. This yeast shouldn't be confused with a "Yorkshire Square" strain such as the type used by Sam Smiths or Black Sheep which are highly flocculant and certainly require pump rousing during fermentaion, and I would think that it is these particular yeasts that Graham refers to in his book as "Northern Type." If you look at the Brewlab information sheet, Yorks 1 is marked as "medium flocculation" and it behaved well for me, fermenting a 1.039 beer down to 1.008 in about 5 days at 20 -21C. A couple of things to check; make sure you aerate the wort well before pitching of if you can't easily achieve this at least aerate the starter as as an alternative. A 1/4 - 1/2 teaspoon of a yeast nutrient such as Brupaks yeast-vit or Wyeast Nutrient added to the wort before pitching ( or at the end of the boil ) will do no harm at all and correct any nutrient defficencies in the wort. This yeast is very suitable for top-cropping if you wish to re-pitch and may need skimming near the end of the fermentation.

Am I missing something here ?

I thought 'flocculation' referred to the yeasts ability to compact down, where 'attenuation' referred to it's fermentation vigour.

Have I got this wrong ?

[Brownster]

Mid/high 20s is a fine to grow starters (the yeast can cope up to 37degC), but ideally the starter temp should be between 18 and 24degC. At warmer temps the yeast's metabolism will be a bit quicker and it will throw lots of flavors and esters but since you are growing yeast not making beer those things don't matter so much. However, too warm and the yeasts cells will be weaker, and too cool you get slower and less growth, and it seems you pushed your starter through both. What might be more an issue than the min/max temperature is how quickly you changed that temperature, thermal shock can cause the yeast to mutate and have other unwanted consequences, so when you put it on, or took it off the heat-mat it may have heated or cooled more quickly than the yeast were easily able to cope with

.

So a thermal shock might have been the cause - enough to mutate the yeast cells, I would add that when the initial starter temp. was too high it was bought down over 24 hours cooling naturally rather than using a cold bath or anything. But still this could be the answer.

I use a stir-plate, but a 1 to 1.5L starter seems like a resonable size to grow yeast for a UK-ale, so if your yeast were healthy and viable, that should not have been a problem.

This is another thing, I look around and get different answers for this, it seems many people get away with just the one 300ml starter from either the bought flask in the case of Wyeast or the agar slant from Brewlabs, and even it would seem in the directions online for growing up a starter from a stored split of yeast. Yet in the John Palmer book and on the Mrmalty website both suggest much higher pitching rates grown up from the sort of size of starter I prepared, it would seem both work but I wonder if using the former has caused problems for others in the past, particularly with stronger 5%+ brews?

I never monitor the SG whilst it's fermenting, only just before when I think it will be done, do you take regular readings of SG / Temperature as a matter of course? I did at one time leave the hydrometer bobbing in the beer but I found that lumps of yeast would attach and weigh the thing down giving a false reading.

On a related note, I've found that BrewLabs "Sussex 1" yeast (which may well be related to the one you are using) also needs similar rousing and attention to get it to attenuate to the levels required.

I have used a Brewlabs Sussex yeast before which I never split, grew up once to 300ml and pitched and it fermented out a charm, but then I never had the problems with temperature control at the beginning.

I've used Brewlabs Yorkshire 1 yeast a few times in the past and haven't found problems or needed to rouse or give additional areation during fermentation. This yeast shouldn't be confused with a "Yorkshire Square" strain such as the type used by Sam Smiths or Black Sheep which are highly flocculant and certainly require pump rousing during fermentaion, and I would think that it is these particular yeasts that Graham refers to in his book as "Northern Type." If you look at the Brewlab information sheet, Yorks 1 is marked as "medium flocculation" and it behaved well for me, fermenting a 1.039 beer down to 1.008 in about 5 days at 20 -21C. A couple of things to check; make sure you aerate the wort well before pitching of if you can't easily achieve this at least aerate the starter as as an alternative. A 1/4 - 1/2 teaspoon of a yeast nutrient such as Brupaks yeast-vit or Wyeast Nutrient added to the wort before pitching ( or at the end of the boil ) will do no harm at all and correct any nutrient defficencies in the wort. This yeast is very suitable for top-cropping if you wish to re-pitch and may need skimming near the end of the fermentation.

That's great to know you have used it without problem, I always aerate by dropping the cooled wort from the boiler into the fermenter which causes masses of foaming which then requires a few hours to dissipate before I can fix the lid. Should I perhaps be more vigilant with this and use a paddle in a drill to give it a real beating? Did you split the initial culture or just use the agar slant the once?

[Oscar Brewer]

Re the original Brewlab slant I used in once, making a 200ml starter which I stepped up to 2L as this particular brew was for 30L. However for a 23L brew of low-medium gravity I've used a 300ml starter direct as Brewlab suggest and the fermentation / attenuation was normal. If I'm re-pitching yeasts I skim some off at after about half way through the fermentation and keep this in the fridge for up to 5 days and then use the necessary quantity for the next brew as determined by the "Mr Malty" calculator. And I streak my own agar slants for medium-long lerm storage. Re the areation question, the method you suggest would seem to be fine.

Re the question of "flocculation," the point I was making is that a yeast with a "medium" rating shouldn't require rousing to reach the required attenuation whereas a strain with a "high" classification may well require some rousing ( by stirring the yeast head back in with a paddle ) to attenuate the beer fully. A high flocculating strain will drop out of suspension ( settle to the bottom or top of the FV depending on the strain ) more quickly than a medium strain and if not roused may leave the beer with a higher final gravity, leading to possible problems later when bottling.

[Brownster]

Re the original Brewlab slant I used in once, making a 200ml starter which I stepped up to 2L as this particular brew was for 30L. However for a 23L brew of low-medium gravity I've used a 300ml starter direct as Brewlab suggest and the fermentation / attenuation was normal. If I'm re-pitching yeasts I skim some off at after about half way through the fermentation and keep this in the fridge for up to 5 days and then use the necessary quantity for the next brew as determined by the "Mr Malty" calculator. And I streak my own agar slants for medium-long lerm storage. Re the areation question, the method you suggest would seem to be fine.

Hi, how many steps do you do? I went from culture + 500ml starter, then added 1ltr giving around 1.8 ltrs approximately. Should I be doing: culture+500ml, step 2 + 500ml more , step 3 + 1 ltr or is that unnecessary do you think?
I am ordering some more of the Yorkshire 1 today to have another go. Meanwhile I am currently in the midst of brewing the Black Sheep Ale again since my order for dried yeasts came in the post today

Cheers,
Wayne.

[Wolfy]

I use a stir-plate, but a 1 to 1.5L starter seems like a resonable size to grow yeast for a UK-ale, so if your yeast were healthy and viable, that should not have been a problem.

This is another thing, I look around and get different answers for this, it seems many people get away with just the one 300ml starter from either the bought flask in the case of Wyeast or the agar slant from Brewlabs, and even it would seem in the directions online for growing up a starter from a stored split of yeast. Yet in the John Palmer book and on the Mrmalty website both suggest much higher pitching rates grown up from the sort of size of starter I prepared, it would seem both work but I wonder if using the former has caused problems for others in the past, particularly with stronger 5%+ brews?

That's because the only real answer you will find is "whatever works best for you". There are many factors that we as home brewers cannot easily measure when growing and pitching yeast and at best even those measures are only estimates. But most confusion is that - as you suggested - there are a number of different and very variable suggestions that all seem to work. Here on these forums, the techniques and methods used show that various people are happy using starter sizes that range from 300ml up to 2L for an 'average' batch of the same beer.

Another important factor when making starters is yeast health, the 'Yeast' book suggests that health might be more important than cell density, because a smaller number of healthy yeast can reproduce and ferment better than a larger volume of sick yeast (which might have been a factor if the first starters you made were not looked after very well).

Brewlab's instructions suggest making a 300ml starter and pitching that directly into your beer - that is quick, easy, and one would assume they know their product and how you can get the most from it - so unless that method does not work, why not try it?
(I'm sure that is where you got the 300ml starter from, because pitching a Wyeast pack into such a small starter would not do it too much good).

Then we have MrMalty, which is a fantastic resource that uses the 'industry standard' pitching rate:
"The general consensus on pitching rates is that you want to pitch around 1 million cells of viable yeast, for every milliliter of wort, for every degree plato"
To simplify the maths lets use 20L of 1.040 wort, which means that calculation suggests 199.9 billion yeast cells.
However then the calculator applies a multiplier for the type of beer you are making, 0.75 for an ale, and 1.5 for a lager, but the interesting thing is that in the recently published 'Yeast' book, the author (who also wrote MrMalty) suggest that a more appropriate multiplier for an UK-ale is 0.5 (but this information is not on MrMalty).
Then to apply another often quoted reference we can "assuming maximum cell density 100million cells per ml" (ref. Chris White) of yest cells in our starter.
So our 20L of 1.040 wort needs either a starter that is 1L or 1.5L.
MrMalty (assuming the 0.75 multiplier) suggests a 1L starter because it assumes you start with fresh pack of 1billion yeast cells not a slant.

Ray Daniels' suggests a "home brew pitching rate" ('Designing Great Beers' pp118) rather than the 'industry standard' rate used by MrMalty, after all we are making beer at home not in a commercial situation. The 'home brew pitching rate' is "A reduced rate that is achievable and gives good results is a total of 10 to 20 billion yeast cells for 5 gallons of beer" , compared to the 200-400 billion the 'industry standard' calls for, so we might get good results from using 10 to 20 times less yeast than MrMalty says! But to add more confusion Daniels ('Designing Great Beers' pp119) says that when using slants, a good cell count in a starter is "50 million cells per milliliter" and so the minimum starter size is 1qt (0.94L) and the optimal starter is 1.2 gal (4.5L). But if we use the previous 10billion/ml assumption, we'd only need a 200ml starter to achieve the "home brew pitching rate"

Re the question of "flocculation," the point I was making is that a yeast with a "medium" rating shouldn't require rousing to reach the required attenuation whereas a strain with a "high" classification may well require some rousing ( by stirring the yeast head back in with a paddle ) to attenuate the beer fully. A high flocculating strain will drop out of suspension ( settle to the bottom or top of the FV depending on the strain ) more quickly than a medium strain and if not roused may leave the beer with a higher final gravity, leading to possible problems later when bottling.

It is disappointing that Brewlab do not provide attenuation information for their yeast, because I don't think that you can assume that attenuation is directly related to flocculation.

I have found the 'high' floculating "East Midlands 1" yeast fermented very quickly, attenuated well, and then dropped out, all within 3-5 days (1.050-1.008 in a week). Where the 'medium' floculation 'Yorkshire 1' and 'variable' floculation 'Sussex 1' (most likely from the Ringwood brewery) like to hang around, get lazy, float in rafts on the top of the wort and do not attenuate well or drop out without attention and rousing (1.037-1.022 in 10 days and then needing daily rousing to get it down more). So my experience is that the attenuation is not at all directly related to the listed floculation characteristic.

[Brownster]

Excellent info Wolfy, thank you, that has shed a great deal more light on the whole yeast subject for me.
I should have a new slant from Brewlab soon then I will be trying again with a much tighter control on things
In the mean time I have taken a bottle of my Harvey's Best Bitter and reclaimed the yeast to make a starter. It's going well now after three days, I shall step up again I think just to be safe(r) !

Cheers,

Wayne.

[Oscar Brewer]

I made a 200ml starter from the slant and went directly to 2L making a total of 2.2L available for pitching. There's no point in making smaller steps which will increase the risk of contamination; x10 is the reccomended industry standard as far as I'm aware. And 300ml if you're only going to make one starter.

My comments on the flocculation and attenuation of Yorkshire 1 was based on my own experience with 2 brews I made 5 years ago according to my records.

Cheers,
Oscar