Something no going right!

[Sean_Mc]

I use a spinning sparge arm and always drain one litre per min, grain bed temp of 70c on the last brew, mash porridge was 2.5 :?

 

[Mark1964]

do you use foil full of holes

 

[Sean_Mc]

No Mark, but I keep the sparge a few mm above the grain

 

[Mark1964]

we have what looks like a garden fork with the ends capped off with 1mm holes in it is specially made for our 32 litre thermo it just sits on top of the mash tun and the water just trickles through the holes but we use a double layer of foil. Ill try next time with no foil see what happens

here it is

 

[BigYin]

What temp was the wort of the runnings that you were measuring to get the specific gravity? Did you take that into account when saying you stopped at 1010?

Hot liquid is less dense than a cooler liquid. I stop sparging when the sg of the hot runnings hits 0990, a value that takes into account the temperature of the runnings being measured.

If you did not take temperature into account when measuring, you stopped sparging far too soon, which would explain the low volume you got. :hmm:

 

[bomberns127]

5 degree lost seems a lot for 2 hours, sparging temp seems a bit low, i normally sparge around 76'c, did your hydrometer state 1010 when you stopped?dont forget the temp correction when sparging, i used beer engine to make a brew and it was pretty much right on the money, to be honest i dont normally measure out the water for the whole brew just the mashing, dont seem to have a problem, i sparge till it reads around 0994-6, this gives me 1008-1010 at normal temp, has every brew you attempt with a brew program come up short?
is your mash well and truly mixed when the water is added so you have no dry lumps of mash in there?
it does sounds like a sparging problem though, i never shut the tap off when sparging, i want a continous run through so it flushes all the sweet wort out, what part of the country do you live, there must be a member close who can help.

 

[Mark1964]

i take samples every 10 mins or so and cool to 20 deg c in a trial jar so i know its correct

 

[Shug]

I realise I could have gotten 20 litres of a reasonable sg, but I guess what I'm wondering is, was it possible to get sg of 1070+ from 5kg of maris otter, and 0.5kg each of munich, caramalt and pale crystal malt?
Maybe I was paying to much attention to beersmith claims, than thinking about what the final abv would actually be.

 

[Ceejay]

Ok, so theoretically the maximum "laboratory extract" is worked out (roughly) as:

5kg pale malt = 5 x 297 = 1485
1.5 kg crystal & munich - 1.5 x 268 = 402

Total maximum gravity points = 1887

(based on lab extract figures in GW's Camra book)

Lets assume 80% mash efficiency, so you'll be looking to extract 1887 x 80% = 1510 points in total. Your target SG is 1070, so every litre of water has 70 gravity points in it.

1510/70 = 21.5 litres

So, in theory you should have collected 21.5 litres @ 1070 based on 80% mash efficiency.

 

[Shug]

Cheers ceejay.
Definately need to sort my mash n sparge then!

 

[Ceejay]

Have a listen to this:

http://thebrewingnetwork.com/shows/564

It may highlight something you've overlooked. It's a difficult one, because it sounds like you're doing everything right. However, the one thing I've learned above everything else about mash efficiency is to slow the sparge down. My sparge usually takes about 45 minutes in total for 28 litres of wort :thumb:

 

[Shug]

Kegged it up last night and had a sneeky wee taster from the hydrometer jar. Might not have got the quantity right, but it tastes everything I had hoped for.
6.4%
All wells that tastes well! :drink: