wy1007, any issues?

[brewbeast]

so ive been brewing a blonde ale type thing (recipe below) and have used wyeast 1007 (german ale)...it seems to have stalled at about 5 brix (1.019 or so)...

i made up a 2L starter (the bag swelled before i put it in)...this was crash chilled and i pitched 3/4, saving the rest

its been brewing since the 16th...ive transferred it to 2ndary after 4 days and wacked it into a keg with polyclar and some hops 9 days later (saturday)....recorded the gravity (stupidly after the transfer was done) as it was at 5 brix....have left it at room temp (around 20-22 here in brisbane) and keep burping excess co2 off it, not that there is much to burp, it may just be co2 coming out of solution?...checked it tonight and it still seems stuck at 5

any ideas? just leave it? im pretty sure a bit of yeast slurry made its way into the keg

i have the 1007 i saved, reckon i build it into a starter and wack it in? will it be safe to ferment in the keg provided i let the pressure off daily?

the other thing i realise now is ive mashed too high for a blonde and i figure the target gravity in the beersmith recipe will be below what i can achieve...but 1.020/1.019 still has to be way too high

any help greatly appreciated


here's the recipe:


Type: All Grain
Date: 9/08/2009
Batch Size: 20.00 L
Brewer: Tom
Boil Size: 23.93 L Asst Brewer:
Boil Time: 60 min Equipment: Brew Pot (6+gal) and Igloo/Gott Cooler (5 Gal)
Taste Rating(out of 50): 35.0 Brewhouse Efficiency: 77.00
Taste Notes: not tasted yet

Ingredients

Amount Item Type % or IBU
3.50 kg Pilsner (2 Row) Bel (3.9 EBC) Grain 87.50 %
0.50 kg Munich Malt (22.5 EBC) Grain 12.50 %
10.00 gm Hallertauer [4.80 %] (Dry Hop 13 days) Hops -
10.00 gm Saaz [4.00 %] (Dry Hop 13 days) Hops -
20.00 gm Pearle [6.00 %] (60 min) Hops 15.0 IBU
10.00 gm Saaz [4.00 %] (20 min) Hops 3.0 IBU
10.00 gm Hallertauer [2.40 %] (20 min) Hops 1.8 IBU
10.00 gm Hallertauer [2.40 %] (1 min) Hops 0.1 IBU
10.00 gm Saaz [4.00 %] (1 min) Hops 0.2 IBU
30.00 L Brisbane, Australia - to be diluted with distilled 1:2 Water
1 Pkgs German Ale (Wyeast Labs #1007) Yeast-Ale



Beer Profile

Est Original Gravity: 1.047 SG
Measured Original Gravity: 1.047 SG
Est Final Gravity: 1.011 SG Measured Final Gravity: 1.020 SG
Estimated Alcohol by Vol: 4.62 % Actual Alcohol by Vol: 3.52 %
Bitterness: 20.1 IBU Calories: 450 cal/l
Est Color: 9.2 EBC Color: Color


Mash Profile

Mash Name: Double Infusion, Medium Body Total Grain Weight: 4.00 kg
Sparge Water: 8.86 L Grain Temperature: 22.2 C
Sparge Temperature: 75.6 C TunTemperature: 22.2 C
Adjust Temp for Equipment: FALSE Mash PH: 5.4 PH

Double Infusion, Medium Body Step Time Name Description Step Temp
30 min Protein Rest Add 7.51 L of water at 55.6 C 50.0 C
30 min Saccrification Add 6.68 L of water at 91.8 C 67.8 C
10 min Mash Out Add 5.84 L of water at 96.5 C 75.6 C

[drsmurto]

5 Brix = ~ SG 1.020 only prior to fermentation beginning.

Once the yeast is added and fermentation begins ethanol is produced which messes up this simple calculation as ethanol diffracts lights differently to sugar.

If your OG was 1.047 then post fermentation, 5 Brix is equal to ~ 1.004 (calcs from here - Link

That seems to a tad low to me...... 90% attenuation is too much for this yeast in my experience.

If you already know about this then ignore all of this and start reading..... now.

Each time i use Wyeast 1007 in my dusseldorf altbier it stalls at 1.020. I then rack it and it kicks off again and normally gets down to 1.013/4 (from an OG of 1.052 - mashing at 65/6).

It surprises me each time i use this yeast as its a very vigorous fermenter, 20L in a 30L fermenter and i still get yeast coming out the airlock.

What temp was the initial 4 day primary ferment at? How vigorous was it?

Taking it off the primary yeast cake after 4 days is way too quick IMO. I would generally leave it for 2 weeks before racking.

Hope that helps!

Cheers
DrSmurto

p.s - this yeast makes a killer altbier and a very nice kolsch. I have also seen it used in APAs and even aussie pale ales!

[brewbeast]

thanks Dr geez can't believe how little i knew about the refractometer...that answers a lot of questions i had regarding my yeast health not just in this brew but in some others....saved me a lot of stuffing around there

taking another measurement its probably more like 6...i had to recalibrate it...which comes out to 1.010

it is very vigorous isn't it...im glad ive saved some and put it away for later

again cheers for that

[drsmurto]

No worries.

Beersmith has a refractometer tool which allows you to calibrate it and then use a refractometer to take readings during fermentation.

I still use a hydrometer cos i like to taste the beer as its fermenting.