First Partial - Low Efficiency

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Finally did my first partial but got much lower than expected efficiency. The recipe is as;

Brew Type: Partial Mash Date: 16/04/2005
Style: Irish Red Ale Brewer: Barge
Batch Size: 42.00 L Assistant Brewer: Rell & Bubby
Boil Volume: 15.00 L Boil Time: 60 min
Brewhouse Efficiency: 44.0 % Equipment: Brew Pot (17L) and Esky Mash Tun (27L)
Actual Efficiency: 35.6 %
Taste Rating (50 possible points): 50.0

Ingredients Amount Item Type % or IBU

3.00 kg Morgans Kettled Extracts - Pale (2.5 SRM) Extract 31.9 %
4.20 kg Pale Malt, Ale (Barrett Burston) (2.5 SRM) Grain 44.7 %
0.80 kg Munich Malt - Wynnum HBS (7.1 SRM) Grain 8.5 %
0.25 kg Wheat Malt - Wynnum HBS (2.0 SRM) Grain 2.7 %
0.15 kg Roasted Malt (Joe White) - Wynnum HBS (644.7 SRM) Grain 1.6 %

25.00 gm Pride of Ringwood [8.00%] (60 min) Hops 11.0 IBU
50.00 gm Fuggles [3.00%] (60 min) (First Wort Hop) Hops 8.1 IBU
30.00 gm Fuggles [4.50%] (30 min) Hops 5.1 IBU
20.00 gm Fuggles [4.50%] (60 min) Hops 4.4 IBU

0.50 tsp Irish Moss (Boil 10.0 min) Misc

0.10 kg Light Dry Extract (8.0 SRM) Dry Extract 1.1 %
0.50 kg Dextrose (0.0 SRM) Sugar 5.3 %
0.40 kg Maltodextrin (0.0 SRM) Sugar 4.3 %

2 Pkgs SafAle English Ale (DCL Yeast #S-04) Yeast-Ale

Beer Profile Estimated Original Gravity: 1.047 SG (1.044-1.060 SG) Measured Original Gravity: 1.044 SG
Estimated Final Gravity: 1.012 SG (1.010-1.014 SG) Measured Final Gravity: 1.010 SG
Estimated Color: 13.3 SRM (9.0-18.0 SRM) Color [Color]
Bitterness: 28.7 IBU (17.0-28.0 IBU) Alpha Acid Units: 1.8 AAU
Estimated Alcohol by Volume: 4.6 % (4.0-6.0 %) Actual Alcohol by Volume: 4.4 %
Actual Calories: 408 cal/l

Mash Profile Name: Single Infusion, Medium Body, No Mash Out Mash Tun Weight: 2.00 kg
Mash Grain Weight: 5.40 kg Mash PH: 5.4 PH
Grain Temperature: 22.2 C Sparge Temperature: 75.6 C
Sparge Water: 12.61 L Adjust Temp for Equipment: TRUE

Name Description Step Temp Step Time
Mash In Add 10.80 L of water at 78.1 C 67.8 C 60 min

I mashed for an hour collected the first runnings and batch sparged for about 10 mins before collecting the remainder. I didn't time my collection rate but had the tap pretty much wide open. I've read in a few places that run-off rate isn't an issue with batch sparging.

I collected 15L of wort at 1.050 which equates with about a 45% efficiency which i boiled for an hour to get 14L. I then diluted this to 42L with the extract added.

What really confused me, though, was that the O.G. then came out at 1.033. Even if the extraction efficiency is low, i figured the extract would still get to an O.G. of 1.045 or so. I am measuring the S.G. at room temp (which accounts for a couple of points) and the wort is well mixed.

Did I run-off to quickly, is the crush poor, do i just suck balls?

Any help greatly appreciated!
Congratulations on your first partial mash. Although with a grain bill of total 5.4 kg of grain, many people would argue this could have been a full mash for 23 litre batch size.

The first partial is a real learning curve, working out how your gear works and how the process works. I recommend aiming for a pale ale of 1.045, IBU's 25, so that if things are a bit on the low side, the beer still works out. I also think that brewers get too tied up in efficiencies for their first few brews and in filling all the blanks in using brewing software. Do not worry about the efficiencies, but next time, either add a bit more extract, or a bit more grain to get your expected og.

Next time, sparge a bit slower, and make sure you stop collecting runoff before the gravity reaches 1.010. Even do two boils, the first runnings in one, the second runnings in the next.

What is holding you back is your boil size. You are not extracting the full value from your grain due to not enough sparge water volume. For instance, I would conservatively guess that 5.4 kg should give around 25 litres at 1.055, not your 15 litres at 1.050.

Maltodextrin is an additive used when making up kits and bits. Many kits end up being too thin in the body, and maltodextrin helps make this body up. Your recipe is well beyond a kits and bits recipe. Use the grain to give you the body of the beer.

Ok, say you have 14 litres at 1.050. This converts to 42 litres at 1.016.
Then you have 3kg LME, and some dextrose and maltodextrin, this should roughly equate to 1.025 in 42 litres. So I would estimate that your starting gravity was 1.041. Your stated gravity is 1.033. After you added your mini mash, LME and dried sugars, did you stir everything really well? The figure of 1.033 indicates to me that your specific gravity sample was not representative of your wort.
What Lager said :)

Really, if you can mash that much grain, why do a partial?

A question about the grain. How was the grain cracked? There are some pics in various threads that show pics of peoples grain crush. Check yours against theirs. Like lager said, with that much grain, your could have done a 23 litre all grain batch. You need to sparge a lot more sweet wort out of the grain rather than diluting with water.

I think you are right on the AG instead of partial situation. i decided to mash a 'heavy' partial in an attempt to get two kegs from my brew day as opposed to one. Until I get the hang of things I will stick to 23L from here on.

I was fairly confident everything was well mixed but now that it appears I will hit an F.G. of 1.012-13 I guess my O.G. was around 40-44. :huh:

As far as S.G. of sparge runnings, do I have to worry about this if I am batch sparging? And what about run-off rate? I read that rate isn't an issue with batch sparging. Is this not the case? I gave everything a good stir last time but next time I might sparge in two batches.

i'm not sure of the crush. I had the HB shop bloke do it and he is a spirits man. I will check the pics. Cheers Pedro

Also A bigger kettle will undoubtedly make things easier as well. Seems I'm spending more on gear than beer :( Not to worry, I will be loving it when I finally get up and running :p

Thanks for all the advice and encouragement. The more info i can take into the next brew the better.


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