Brew Day: Craftbrewer Double Chocolate Porter-June 7, 2009

Brewday: Craftbrewer Double Chocolate Porter - June 7, 2009

Recipe Values:

Volume to fermenter[ltr (gal)]:	24.00	Total volume[ltr (gal)]:	25.68	Losses [ltr (gal)]:	1.68
Original Gravity[SG]:	1.055	Colour [SRM(EBC)]:	46.74(92.08)
Mash Efficiency [%]:	65.00%	Bitterness[IBU]:	42.72

Preboil Values:

Mash water volume [ltr (gal)]:	28.06 (7.41)	Mash tun volume [ltr (gal)]:	43.98 (11.62)	Mash tun loses [ltr (gal)]:	1.50 (0.40)
Preboil wort volume [ltr (gal)]:	55.00 (14.53)	@ mash out temp.	56.31 (14.88)	Preboil gravity [SG]:	1.027

Postboil Values:

Evapouration [ltr (gal)]:	30.00 (7.93)	Evapouration Rate [ltr (gal)/hr]:	20.00 (5.28)	Boil time [Minutes]:	90.00
Postboil wort volume [ltr (gal)]:	25.68 (6.78)	@ boiling temp.	26.75 (7.07)	Boiler lose [ltr (gal)]:	1.00 (0.26)
Postboil target gravity [SG]:	1.059	mash items only	1.059

Style: 12B. Robust Porter

Description:

Developed by Ross from Craftbrewer, adapted for Chalks brew rig.

Estimated Original Gravity[SG]: 1.059	Estimated Final Gravity[SG]: 1.013	Alcohol By Volume[%]: 6.20
Bitterness [IBU]: 42.72	Colour [SRM(EBC)]: 46.74 (92.08)
Balance: 1.598	BU:GU ratio: 0.720

Fermentables

Type	Gravity [SG]	Gravity(%)	Weight [gms (lbs)]	Weight(%)
Amber Malt (Bairds)	1.003	5.16%	413.14 (0.91)	5.15%
Brown Malt (Bairds)	1.005	8.10%	703.46 (1.55)	8.77%
Carafa Special Type 2 (Weyermann)	1.001	2.43%	234.49 (0.52)	2.92%
Caramalt Malt (Barett Burston)	1.004	6.87%	580.63 (1.28)	7.24%
Chocolate Malt (Bairds)	1.002	2.85%	234.49 (0.52)	2.92%
Chocolate Malt Pale (Bairds)	1.002	2.85%	234.49 (0.52)	2.92%
Maris Otter Malt (Thomas Fawcetts Floor Malted)	1.036	60.01%	4678.55 (10.31)	58.36%
Munich II Malt (Weyermann)	1.007	11.72%	937.94 (2.07)	11.70%

Hops

Hop Utilisation Method: Tinseth

Type	AA(%)	IBU	IBU(%)	Weight [gms (oz)]	Time(minutes)
Magnum	13.10%	19.25	45.07%	17.80 (0.63)	60.00
Willamette	4.60%	15.11	35.38%	39.78 (1.40)	60.00
Willamette	4.60%	8.35	19.55%	21.98 (0.78)	60.00

Yeast

Type	Flocculation	Attenuation	Min Temp[C (F)]	Max Temp[C (F)]	Alcohol Tolerance
Nottingham British Ale - Danstar	High	78.00%	14.00 (57.20)	21.00 (69.80)	Medium

Estimated required yeast cells (billion):

247.50

Dried yeast (gm):	13.16

No of liquid yeast(Wyeast/Whitelabs) packs:	2.63	(Assumes 94% viability)

Approximate amount of solid slurry (ml):
One hour settling	351.06	(Assumes 25% trub and 94% viability)
One day settling	175.53	(Assumes 25% trub and 94% viability)
Longer than 1 week settling	91.67	(Assumes 25% trub and 80% viability)

Note yeast viability reduces greatly over time as demonstrated in the table below.

Age	Viability	Age	Viability
1 week	80%	2 weeks	70%
3 weeks	60%	4 weeks	50%
5 weeks	40%	6 weeks	25%
7 weeks	15%	8 weeks or older	less than 10%

Viability deterioration varies greatly between different yeast strains. You should consider doing a yeast starter for any yeast older than 2 weeks to ensure yeast viability prior to pitching.

Liquor to grist ratio [ltr/kg]:

Saccrification rest - 3.00 to 4.00 [ltr/kg] is recommended.

A lower liquor to grist ratio will produce a less fermentable wort (with more complex sugars) while a higher liquor to grist ratio can result in a more fermentable wort.

Both extremes will require a longer rest time ( up to 90 minutes )

Protein rest - less then 2.50 [ltr/kg] is recommended.

Mash Schedule

Name	Method	Step temp [C (F)]	Step time [minutes]	Addition amount [ltr (gal)]	Addition temp [C (F)]	Liquor/grist ratio [ltr/kg]
Saccrification	Direct	67.00 (152.60)	60	0.00 (0.00)	0.00 (32.00)	3.20

Mash Details

Mash water required [ltr (gal)]:	28.06 (7.41)	Mash tun volume required [ltr (gal)]:	43.98 (11.62)
Grain Weight [gms (lbs)]:	8017.19 (17.67)	Mash gravity @ 100% conversion [SG]:	1.100

Number of batches:

General:

Minimum required efficiency:	65.00 %	Max expected efficiency	91.73 %

Sparges:

Sparge No	Water addition [l]	Expected recovered volume [l]	Required gravity	Max expected gravity
1	10.54	27.50	42.51	60.74
2	27.50	27.50	12.23	17.47
Combined	38.04	55.00	27.37	39.10

Assumed constants:

The following are assumed in calculations below and will eventually be able to be set.

Absorption [l/kg]:	1.3	Grain displacement [l/kg]:	0.67