Mash Efficiency

[Gurgeh]

Absolutely certain this has been covered many times - I did a few searches of the forum and got over a 1000 matches each time. None obvious.

My mash efficiency is routinely 50-60%.

Some details:

5KG MO - have tried two different suppliers. both fresh. - 3.5L liquor per kilo

mash temp - 66C, dropping to 64C over 75 minutes.

sparging temp - 80-90C. lautered through a false bottom. continuous sparge - continuing until I have collected 25L

I used 200g chocolate malt & 30g black patent malt to try to lower mash PH a tad...

Hydrometer readings adjusted for temperature.

I reckon on my potential being over 60 points: (5x300/25) and that ignores my chocolate & black patent malts

but my BG at 53C was 1.030 - which corrects to 1.042 giving me 70% efficiency.

I have just ordered some CRS & DLS from H&G, thinking that it must be something to do with the water.

Could PH be responsible, or should I just mash for longer?

Gurgeh

[RabMaxwell]

You could also give PH 5.2 a go some people seem to be getting better efficiency using it

[PieOPah]

There could also be a problem with your sparging method. I have no idea how you are doing this...

Too quickly won't give the sugar time to dissolve properly.
Also possible that you are causing 'tunnels' in the grain meaning that the water will take the course of least resistance - again this means not all the grain is being covered lowering efficiency.

[Gurgeh]

I might just do that - have been following the threads on that topic too.

I figure I'll change one thing at a time though and try the CRS & DLS first. My understanding of that treatment is that the PH will be dropped and the extra calcium I need will be introduced. I did the calculations on the brupaks website a couple of days ago so i'll try a mash on the weekend and see if that works any better.

Thanks,

Gurgeh

[Andy]

Can you give us some more detail on your mash tun also ? What type is it and how much deadspace is there beneath your false bottom ?

And re: sparging, do you keep the water level above the grain bed ? If so what was the depth of the water level etc etc ? What was the SG of the runnings when you stopped collecting ? (If you collected to 25L only and there were still viable sugars in the mash then that would hit your efficiency).

70% is still a good efficiency BTW and grain is cheap

[Gurgeh]

I followed a link from another thread - AG newbie or something:

http://hbd.org/cascade/dennybrew/

and found...

The more inefficient your lautering system is for fly sparging, the bigger the gain in extraction you’ll see from batch sparging.

I'm using a stainless steel frying pan guard, plugged into place very tightly with a length of hose which i have cut all the way down it's length and suspended off the bottom of the mash tun with marbles. There's not a lot of recirculating to do so i think I might switch to batch sparging...
[/url]

So there we go!

Gurgeh

[mysterio]

70% is darn good, I don't know why you're complaining! Remember higher efficiencies don't necessarily make your beer better, they just save you around 50p per five % points of efficiency.

[oblivious]

Denny conn’s site is an invaluable tool!

[Gurgeh]

Can you give us some more detail on your mash tun also ? What type is it and how much deadspace is there beneath your false bottom ?

And re: sparging, do you keep the water level above the grain bed ? If so what was the depth of the water level etc etc ? What was the SG of the runnings when you stopped collecting ? (If you collected to 25L only and there were still viable sugars in the mash then that would hit your efficiency).

70% is still a good efficiency BTW and grain is cheap

It's a 5Gallon boots fermenting bin, which i've put a drum tap in the side of - as low as i possibly could. the frying pan guard with the rubber tubing around the edge fits very tightly a couple of inches from the bottom, but the goods push it down onto the marbles - which i put there to make sure it wasn't pushed all the way down. I'd say my ullage is about a pint, but next time i'll be putting in a tube so that this reduces to less than a quarter pint. I did notice that the ullage (which of course i couldn't get to until tipping out the spent goods) was quite dark, so obviously a decent gravity.

I am a follower of Palmer, so i have been sparging to maintain an inch above the grain bed.

do you think that the pint of ullage i mentioned could be responsible for such a drop in efficiency? I had assumed that the ullage would be as low a gravity as my final runnings, but perhaps there is some sort of thermocline effect happening.....?

I'm afraid I didn't take a hydro reading for the last runnings. Wish I had now!

Gurgeh

[Gurgeh]

70% is good? Oh Okay!

I've been delving to deeply into the technical stuff at the back of Palmer - he reckons i should be getting 98% with a false bottom and 85% with a pipe manifold i made earlier.

Just hate to think I'm throwing out something of use to me!

so 10p per 1% efficiency then... Perhaps I'll just get on with enjoying it and stop worrying - hey actually that suggests £10 per brew, so it's a bit less than that for me actually!

Cheers,
Gurgeh

[Andy]

I am a follower of Palmer, so i have been sparging to maintain an inch above the grain bed.

Right, I'd start with reducing that inch to 1cm maximum. You only need to keep the grain bed floating so keep minimal sparge liqour above the mash bed. Too much and the liqour will find the path of least resistance which is down the bin sidewalls, bypassing the mash.

do you think that the pint of ullage i mentioned could be responsible for such a drop in efficiency? I had assumed that the ullage would be as low a gravity as my final runnings, but perhaps there is some sort of thermocline effect happening.....?

That's not much deadspace so shouldn't be a big contributor to efficiency loss.

I'm afraid I didn't take a hydro reading for the last runnings. Wish I had now!

Worth doing, keep collecting until you reach 1006 (1010 is better) - if you can't fit all the collected wort into your boiler then you can use the excess collected to top up the boil as wort evaporates. If you're just stopping when you've collected 25L then there may well be more extract available in the mash. That would hit your efficiency.

[Andy]

Oh, DaaB will be along soon to have some words about Palmer

[Gurgeh]

Oh, DaaB will be along soon to have some words about Palmer

Whoops!

[Calum]

I wouldn't worry about trying to attain laboratory type efficiency.

I was at the SCB AGM in Kirkcaldy on Sunday and we had a very interesting talk from Stuart Cail who in head brewer at Harvieston. The efficiency question was brought up and his opinion was that rather than working by numbers and science to try and gain the best efficiency that you should taste the final product and then analyse what you did to produce it. The efficiency calculation is just one of the many indicators that you can use to gain an understanding of your process (rather than rule your process).

For what it is worth, he mentioned that Harvieston achieve around 85%.

[Gurgeh]

That's pretty conclusive then!

Thanks for your advice folks.

Gurgeh