Danstar Windsor Attenuation

[Brownster]

Hi All,
I've just recently brewed a 'Hook Norton Hooky Dark' from the latest GW book. I've been using SF04 but had heard it mentioned that all though not so good at flocculating, Windsor imparted some good flavours, being a bit adventurous I decided to try it out.
The OG was 1031 and the target FG 1006, which seems quite low, anyway, it's fermented down to 1012 which is some way off the target. I checked the SG after 5 and 7 days and no further drop, decided to 'rouse it up' by gently stirring, checked the temperature and it was 18C (I use a heated beer thermostat thingy), left it another couple of days and no change, still 1012.
After reading various posts on the forum I heard it mentioned that this yeast does not attenuate so well as others (SF04?) so my question is, do you think it's the yeast that's hit it's natural level or do you think I've suffered a stuck ferment?
BTW I did a starter bottle as per the instructions on this site (the tips section) and it was fermenting extremely well before pitching, had a good head on it for three days at least.
I shall bottle in a couple of days after letting it settle a bit and have a taster, hopefully the flavours good which is the main thing, it's just going to be an extra weak beer, about 2.7% instead of the intended 3 or so %. I wanted a weaker session beer but perhaps not THAT weak!!!

[simple one]

Yes I would say it had finished. Thats about a 61% attenuation. Low, but I think this is just in the range for Windsor, which is one of the poorest attenuating yeasts (i have been told). You may expect a drop of a gravity point in condtioning, and maybe the priming sugars may make a slight rise in the final ABV. I get an alchol ABV for 2.5% for this using the calculator on this site.

Now, there are 2 ways you could up it slightly if its really important to get nearer the 3%. One way. By using the sugars already in solution is to rack the beer to secondary and introduce a starter with a more aggresive (attenuative) yeast. The lowest FG I calculate it would go down to would be around 1008, 3.03%.
Disadvantages- Increased risk of infection, oxidation and it might not shift the 1012 gravity one bit, the body of the beer just might not be fermentable (at all/enough). The beer will have a mixed yeast flavour profile.

Second way is to introduce some sugars to the solution. The ways are end less from spray malt or tins of malt wort which shouldn't thin the beer to much, to probably a less favourable option of syrup, simple sugars..... although honey might be a good idea. What ever you add, calculate the amounts needed, boil it in some liqour and add.
Disadvantages- Changes the recipie. Slightly increased risk of oxidation and infection. Simple sugars may thin the beer, making it dry.

There is a third way.... And you get to keep all of the original flavours from your recipie....... Just bottle/keg and put it down to experience for dealing with windsor in the future.

[Brownster]

Yes I would say it had finished. Thats about a 61% attenuation. Low, but I think this is just in the range for Windsor, which is one of the poorest attenuating yeasts (i have been told). You may expect a drop of a gravity point in condtioning, and maybe the priming sugars may make a slight rise in the final ABV. I get an alchol ABV for 2.5% for this using the calculator on this site.

Thanks for the reply Simpleone that explains things, as an aside I d/loaded the GW beer engine s/w and pumped the ingredients in there and got a lower OG figure / FG too. EDIT: I had missed off the sugar addition in the recipe software, it does in fact match, that will teach me to get the book in future! /Edit
It raises another question, is this lower attenuation the ability to ferment out the last little bit as such? The reason I ask is because of future brews. Given that many recipes are around the 1010 FG range could I expect that it will end at 1012 ish again or, like this recipe, always an additional 4 - 6 points higher regardless of specified FG?
Am I right in thinking that the FG is largely dictated by the unfermentable sugars that remain in the beer, a product of mash temperature and possibly certain grains and their sugar profile?
Speaking of mash temperature - the recipe said 67c, when I pitched the grain it went to about 70c whilst I adjusted it down with cold additions, the whole process would have taken no more than 5 minutes, after which it was bang on the money, could a short spell at a higher temperature have an effect? My whole theory with the strike temp. is to overshoot slightly on the basis it requires very small additions of cold to adjust down rather than the other way, perhaps this is a problem?

Funny thing was I bought the ingredients for two brews, the other being a 'youngs special', a bit stronger at about 4.7% , I bought some SF04 too and decided on using the Windsor in the mild in the end on the basis that if it didn't clear too well it wouldn't notice so much

[simple one]

Heres how i understand it. Lower mash temperatures, around 62-63C ish will encourage the enzymes to produce more simple sugars from the starch compounds. A higher temp, 67-68C will produce more complex sugars. Now, some yeasts will convert simple sugars easily to alcohol, but when presented with more complex sugars fail to convert (like windsor), leaving a higher gravity. Other yeasts (like nottingham or to the extreme, champagne yeast) tend to munch through most sugars. There will always be a positive gravity in AG because the grains leach other non fermentable compounds in to solution (esp darker malts).

There will always be some compounds left in an AG wort after fermentation which will give some sweetness and body. But how much will depend on yeast and mash temps.

I think though we also forget the recipie itself to. If there is a large amount of additions which add to colour and flavour (eg roasted malt) but not sugar, then the the OG and FG will be higher. This is usually taken in to account in most brewing software though.

I love S04 yeast because of what it doesnt do, more than what it does. S04 leaves compounds from the malt which give the beer character. I hate nottingham yeast because it ferments/conditions compounds that S04 leaves behind. Although some say this makes the hops come to the forefront. Windsor is like an extreme version of S04, It leaves more malty (grain flavour) taste by fermenting and or conditioning less sugars and unfermentables.


Matt

[simple one]

Firstly I have never used it, but looking on this forum and talking to people that have. I would have said that it was regarded as the least attenuative yeast.

So if they describe it as moderate what yeast sits in the low bracket?

And I know this sounds odd, but just reading the first part of the thread, it just sounds finished.

Chris, what are the reasons behind a stuck fermentation? What processes are best avoided to prevent them?

[Parp]

I recently used Windsor for the first time in an all grain brew using Pale, Vienna, Amber and Light Crystal malts.

It went from 1054 to 1013.

Fermentation was steady and the flavours are good. It also cleared out no bother (Bottles).

If I can get that sort of performance regularly, I'll probably not bother with S-04 again.

[Philipek]

Excellent thread!

Very informative as to Windsor's pros and cons.

I'd been wondering about Windsor yeast and all the information I could find was the pithy description on the Danstar website.

[simple one]

Cheers chris.

Brownster what you doing with it? Lets us know the results.

Personally I would taste it. If it tasted not to sweet then I would bottle it. Just using less priming sugars. There is a risk of bottle bombs if it suddenly drops to 1006, but I can't see it.

[Brownster]

Windsor is described by Danstar as having a moderate attenuation, i'd put that in the low 70's. I'd want to try and get that gravity down closer to 1010 before racking from the primary.

Reading what you're saying along with Matts' advice makes me think perhaps I should try adding another yeast starter but I don't want to ruin it now by oxidising it either. What I will do is have a taste as suggested and see what it's like, if the flavours good and not too sweet I'll bottle as is, if on the other hand it's too sweet I might have to attempt a re-start with SF04

I recently used Windsor for the first time in an all grain brew using Pale, Vienna, Amber and Light Crystal malts.

It went from 1054 to 1013.

Do you know if the FG was as low as predicted, by recipe, software or otherwise? It would be interesting to know for future. From what you have said, the flavour was good.

From what has been said so far it would seem reasonable to expect a higher FG using Windsor but how much higher is less predictable, perhaps I can use the attenuation figures you mention in comparison with SF04 to achieve an approximation of a likely FG? Is this where you have got your 1010 from Chris?

Thanks Chris and Matt for all your advice, it's much appreciated

[Parp]

Do you know if the FG was as low as predicted, by recipe, software or otherwise?

It actually attenuated one point further that the software expected.

I was happy with its performance for that starting gravity and that ale style, an ESB.
It tastes balanced, I wouldn't say it was sweet/underattenuated.

[Brownster]

It actually attenuated one point further that the software expected.

I was happy with its performance for that starting gravity and that ale style, an ESB.
It tastes balanced, I wouldn't say it was sweet/underattenuat

That's good to know it worked so well for you

perhaps I can use the attenuation figures you mention in comparison with SF04 to achieve an approximation of a likely FG?

SO4 reputedly has an attenuation of 73% which I think is more likely derived from combined personal experience rather than figures published by the manufacturer. Yeast doesn't always play the game though, I tend to get closer to 80% with it and others probably closer to 70%.

Is this where you have got your 1010 from Chris?

Basically. The only official information we have is that Windsor is described by the manufacturer as having moderate attenuation but so is SO4, we know that most people (certainly not everyone though) report getting a lower level of attenuation with Windosr than SO4 so it's not unreasonable to work to 70% with this yeast ie this would fall into the moderate attenuation bracket given by the manufacturers and it's a shade lower than SO4.

1009 would be approximately what I would be aiming for if I was pitching this yeast myself but fermenation has stalled and the yeast might not be in the best of shape so although I think you need to try and get it lower I wouldn't want to influence you to into chasing something that might not happen. IMO 1010-1011 would make quite a pleasant mild. Much above that and you'd need to taste it and make a judgement whether you are happy with any underlying sweetness that may be there.

Thanks for all this info. I'm learning so much with each brew yeast attenuation is another area I now know a little more about, I'll have to do a bit more reading up on it.

The good news is I did a taster today and it's pretty damn lovely by all accounts no noticeable sweetness just a lovely maltiness with good hop character, also quite soft, noticeable less bitter than my other brews which is to be expected with smaller quantities of bittering hops. A good session beer which won't get me too kerfuddled...
I'll get it bottled this week and move onto the 'Youngs Special' recipe.

[Robdog]

Ive been wanting to try Windsor so think i may give it agio next i order yeast.

I never seem to get below 1012 even with Nottingham. Not sure what im doing wrong like but the results i get are always tasty but i want to try a yeast that gives a bit of character to the brew.

[johnmac]

Windsor gives a lovely taste but the slow floculation is a pain. I plan to brew a strongish IPA with Winddsor in October and leave it in the garage until February. If it's not clear by then, you'll probably hear me scream

[Parp]

I bottled a windsor batch after 10 days in the fermenter and It cleared nicely at room temperature.

It had dropped a hell of a lot in the first 24hrs and by about the 4th day was almost crystal.

[Brownster]

Well I bottled the 'Hooky Dark' today without any sugar added as the 1012 FG is higher than expected. I'll see how the the Windsor yeast settles over the next few weeks and post back the results. In the mean time I have a not quite full bottle that needs 'finishing off'