Windsor attenuation - 77,5%

Having used Danstar Windsor several times without getting the attenuation needed, I decided enough was enough and grabbed the bull by its horns.
I mashed low, rehydrated properly (@35°C), aerated and fermented slighly warm at an ambient 21°C temperature.
It fermented from 1.054 to 1.012 in less than 48 hours = apparent attenuation of 77.5% - yes! - using Danstar Windsor ale yeast.

I thought I'd share the experience, so here's my recipe and notes:

Style: Extra Special/Strong Bitter (English Pale Ale)
Batch size: 20.5 l
Boil volume: 29.0 l
OG: 1.054
FG: 1.014
Bitterness (IBU): 42.6
Color (SRM): 10.6
ABV: 5.3%

Grain/Sugars:

4.50 kg Pilsener (Belgian), 86.5%
0.30 kg Crystal 50-60L (British), 5.8%
0.20 kg Brown Malt (British), 3.8%
0.20 kg Amber Malt, 3.8%

Hops:

33.00 g Challenger (AA 7.3%, Pellet) 90 min, 32.2 IBU
30.00 g Fuggles (AA 4.0%, Pellet) 20 min, 9.1 IBU
30.00 g Fuggles (AA 4.0%, Pellet) 2 min, 1.3 IBU

Yeast/Misc:

Danstar Windsor, 1.0 unit(s), Yeast

Recipe Notes:

Mash as low as possible - Windsor will poop out early anyway and leave lots of residual sugar. Carbonate below 2 vols.

Batch Notes:

25/9 2013
Mashed at 60°C for 1 hour in 15 liters. Drained and batch sparged (added 19.5 liters) . Used bottled, low mineral water (Laqueille, eau de source de montagne)
Ca=6.5; Ma=2; Na=4,4; CaCo=44; Cl=1; So=0,2
26/9
Boiled 31 liter wort for 2 hours.collected 20.5 liters to ferment. OG=1.054. Rehydrated yeast in 1.5 dl, sterile water @ 35°C, 20 minutes, then cooled down to 22° (10 mins) before pitching into wort at 24°. Aquarium pump with 0.5 micron stone ran for half hour before and half hour post pitch.
27/9
Vigorous fermentation for 24 hours, then sudden dropout, SG=1.014 - 24 hours post pitch. My best attenuation result thus far using Windsor.
28/9
SG=1.012, Very cloudy. No more activity in airlock.

29/9
sg=1.012

01/10
sg=1.012

Interesting...and how does it taste after fermenting that high?

It's fruity, but not extreme - (no nail varnish/banana/bubblegum).
Also, not as sulfury as it has been with other beers i brewed.
Judging by the fresh hydrometer samples - I detect no obvious flaws, and I think this will become a very drinkable ale in a few weeks, when bottled and carbed.

I wonder if it's the combination of mashing low and fermenting high, or more one of the two? I'm about to brew an ESB with Windsor, I might try mashing close to 60C, and fermenting at 19C to see how that works.

CarnieBrew said:

I wonder if it's the combination of mashing low and fermenting high, or more one of the two? I'm about to brew an ESB with Windsor, I might try mashing close to 60C, and fermenting at 19C to see how that works.

Click to expand...

Having used both, I'd choose S-04 over Windsor in an ESB any day of the week. Pitch around 60-62*F, hold at 63-64*F the first few days then let rise to finish at about 68*F.

Do you really want to mash this at 140*F (60*C)? Why? The ESB I have in my keezer right now I mashed at 150*F, used 1968ESB, and it's fairly dry. Next ESB batch, I'll mash at 152-153*F (67*C) for a more balanced character.

@CarnieBrew
My feeling is the low mash temp has more to do with my result.
If I had the possibility to ferment lower, I would have done it.
Also I'd make sure to rehydrate as per danstar.
I would appreciate to hear how it turns out for you.