AG#31 Raspberry Blonde

It’s been a while (AG#31 British Hopped IPA, still to write up).  This one is my entry for the Northern Craft Brewers & Saltaire Brewery competition.  

“The Homebrew Competition is to brew a speciality beer:
It could contain Herbs, Spices, Vegetables, Fruit but the idea is you get a 5th ingredient to compliment and add to the Water – Malt – Hops – Yeast”.

I decided to play it safe and go with a simple recipe.

Original Gravity (OG): 1.044
Final Gravity (FG): 1.010
Alcohol (ABV): 4.46%
Colour (EBC): 7.3
Bitterness (IBU): 24 (Average)

2.800 kg Golden Promise Pale Malt
0.800 kg  Pale Wheat Malt

10g Amarillo (8.7% Alpha) @60 minutes from the end (Boil)
30g Amarillo (8.7% Alpha) @10 minutes from the end (Boil)
50g Amarillo (8.7% Alpha) @0 minutes from the end (Boil)
1.400 kg Raspberries (from frozen) in secondary for 5 days

WLP001 California Ale Yeast.

Strike temp of 74C, 9.0L liquor for 3.600kg grain. Mashed in at 66C (single step infusion).   Mashed for 60 minutes.   First runnings 1.082.  Sparged at 76C 19.8L liquor.  Collected 24L at 1.040. 60 minute boil.  Amarillo in at 60 minutes (from the end of the boil), followed by additions at 10 minutes and 0 minutes.

I collected 18L of wort, post boil, with an OG of 1.044.

Pitched WLP001 California Ale Yeast starter at 19C.

Update: 10/02/14  1.024 

I’ll be transferring to secondary and adding 1.400 kg of raspberries (bought forzen and defrosted).

Update: 16/02/14 – Added 1.4kg raspberries to 18L. The FG was higher than expected at 1.014, making the beer nearer 4.0% abv

Update: 22/02/14 – transferred off raspberries. 15L.

Update: 28/02/14 – bottled 15L primed with 75g sugar syrup (5g/L to achieve 2.5 vols).

Not the most intersting of brewdays, or recipes, but the beer will hopefully be well balanced, with the raspberries the star of the brew.  This was a straightforward recipe, and I managed to make a note of most of my volumes and gravity readings, so thought I would try and understand ‘efficiency’ a little better.  My current understanding is poor, and it’s one of those things that I think “I’ll worry about it next time”.  To make things more confusing, an online calculator gave me one answer, and my calculation based on ‘the maths’ (edit: 12/02 – removed Brew Your Own, & Brewer’s Friend links – see update below), gave me a different answers (see below).  What I have learnt is that efficiency can be measured at each stage of the brew, and that my system, the water profile and the grist will affect efficiency.  I definitely want to get to the point where I can use efficiency calculations and brewing records to influence my brewday planning; but until I’m in a position where I have a brewkit that’s not botched together with whatever I can borrow, I’m not going to get hungup on grist and water treatment variables, too much.  Having a degree of certainty around temp and liquor losses should come first, right?

Back to this brew (I might brave a post on efficency another time).  I asked Twitter to help me out with my efficiency confusion, and the ever-reliable folk helped me out.  Thanks to; @hopsinjoor @RoostersOl @Jimthebrewer @BigAdeBrewing @Dunloptired and @tw05ers for their suggestions.   Al (@hopsinjoor) kindly shared his brew spreadsheet, which I’ll use when I have my kit ‘dialled in’

As ever, thanks for reading, and your comments are – almost – always welcome.  I’m sure there will be comments, as my understanding of efficiency; and the calculations above will be riddled with mistakes.  Hopefully, with practice, reading and comments, I’ll be able to put a more useful post together at some point.

Edit: 12/02 – see comments on efficiency:

The product of volume and gravity in brewers degrees.
For instance…
10 litres at SG 1.040 = 10 x 40 = 400 Litre.degrees.

The maltsters give laboratory extracts for the malts which you might  think of as the extract 1 kg would give in 1 litre. If that were actually possible. For decent pale malts this is probably around 300 (assuming a coarse crush / moisture as is).

That’s to say, one kg of malt mashed under ideal conditions would give you 1 litre of wort with a gravity of something like 1.300.

So, for an example homebrew mash:

Pale malt: 2.8 kg @ 293 L.deg per kilo = 820.4
wheat malt: 0.8 @ 296 = 236.8

You can get these values for extract from a recent malt analysis, but you can look up typical values on the InterWeb , or you could call it 300 and wouldn’t be far wrong.

Total potential extract 820.4 + 236.8 = 1057.2 litre.degrees

What you actually get out of the mash might be 24 litres at 1.040 Specific Gravity, i.e…
24 litres x 40 degrees = 960 litre.degrees

So your mash efficiency is something like…
 960/1057.2 = 0.908 = 90.8%

Post-boil, you might end up with…
 18L @ 1.044 i.e 18 x 44 = 792 and 792/1057.2 = 0.749
That is..74.9% which you might call brewhouse efficiency.

“Thanks Prof!” – full post and source here.

 

 

Advertisement