Low Efficiency

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NegFerret

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Hi,

I've recently followed Leedsbrew's Black Chocolate Stout recipe, but have suffered a pretty appalling efficiency.

I had a similar issue on the last brew (AG#3, Big Kenny) but it wasn't quite so severe. I had put it down to sparging too quickly and at a low temp (I moved the sparge water off the hob so may have lost a few degrees).

This time I was sure to keep the sparge water on the hob at a stable 76C, and sparged slowly.

The only thing I thuoght it could be is the liquor/grist ratio, I think I've been using 3litres to a kilo whereas previously I'd been using 2.5l to a kilo. Could this cause a problem?

I'd also wondered about sparging, with the high ratio I have not had much water left to sparge with. If I run out and don't think it's done can I continue to sparge with the wort? Should I prepare more liquor and keep sparging until it's running clear?

Any help appreciated, I was over 30 points down on the stout so it's likely to be a poor 6% :shock: Hopefully still tasty though!
 
I've used a 3:1 ration without any problems, but that was batch sparging. I think efficiency tends to drop with very high gravity beers but I don't have much experience of high OG brewing.

What was the gravity when you stopped sparging?
 
Hi Mumbler.

I should've mentioned that I fly sparge, through a collinder. I try to cover the whole area.

The expected gravity was 1098, and I think I managed only 1064. I'm using Beersmith and I'm possibly being too reliant on it calculating things for me.

When I searched the forums one of your early posts was the first that popped up! I'm hoping the channeling isn't my issue, as I have no idea what to do about that.

edit: sorry, just realised you asked for the gravity after sparging. I think I had 1052 with 12 litres, I was aiming to boil off 2 of those litres in 90 mins.
 
Sorry I meant the gravity of the runnings at the end. I guess if they were high then you might have wanted to sparge more and boil off more water. I've little to no experience of fly sparging though so I might be wrong there.
 
Aha, that's a good point. I need to be measuring the runnings to see if the sparge should continue.

I don't think I'm sparging enough, I think I need to whack a few more litres through it until it becomes very low gravity. Thanks for the help Mumbler :thumb:

If anyone else has any comments don't be shy :D
 
Whenever I do higher OG beers my efficiency is nowhere near my normal levels.

I've no idea why, so not much help there ( although it may be common and you don't actually have a problem, we're just calculating wrong? ) , but am watching this thread for any good answers...
 
The fly sparge rule I use is to stop the sparge when the SG of the runnings hits 0.990

If you stopped sparging before that, then you haven't extracted all the available sugars, which will give a lower efficiency.

Obviously the more liquid you lose to evaporation during the boil, the higher the resultant SG will be post boil, so you might have lost out there?
 
BigYin said:
The fly sparge rule I use is to stop the sparge when the SG of the runnings hits 0.990

I stop around 1008, any lower you'll start to get tannin extraction
 
seanipops said:
Tell me more about tannin extraction, it sounds bad.

Chew a dry teabag - that's what it tastes like. Usual cause is mash temperature far too high or sparging too long so the pH rises too high.
 
Yeah 1008 with temp adjusted, well to tell the truth I use a refractometer so it only takes a few seconds to temp adust
 
You will find if you dont stop sparging at 1.1010 or below your readings on your hydrometer will start to go back up which means you have extracted the tannings from the grain. You must take regular readings with a trial jar and hydrometer when sparging. We start testing 5 mins into the sparge by collecting some wort from the mash tun in a trial jar then run it under the tap till the temp of the wort is 20 deg c then test with hydrometer. Do this all the way through the sparge till you get a reading of 1.1010 or below then stop :thumb:
 
I'm so annoyed with myself for not carrying on sparging! I reckon I coulda got quite a bit more out of it and been far closer to the gravity I wanted.

Thanks for all your help guys!
 
johnluc said:
hi when you say to stop sparging at 0.099 or 1.008 does this take into account temp adjustment.


0.990 is the temperature correct reading assuming the runnings are coming out of the mash tun at around 68c. That is equivalent to 1.010 at 20c. :thumb:
 
as the previos poster says, get a refractometer. Less than £20 off ebay. It will save you ages on a brewday. And you get to look like a scientist, you could get a labcoat too!
 
BigYin said:
johnluc said:
hi when you say to stop sparging at 0.099 or 1.008 does this take into account temp adjustment.


0.990 is the temperature correct reading assuming the runnings are coming out of the mash tun at around 68c. That is equivalent to 1.010 at 20c. :thumb:

Sorry BY, wondered how you were getting down to 990 :oops:
 
I sparge to a length not a gravity.
My boiler will reduce at the rate of 5ltrs/hour, so for a 1.5 hour boil I need to sparge to 7.5ltrs over required length.
23ltrs required = 30.5ltrs sparge.
Never used one of these new fangled brew calculators yet, normally end up +/- 2 points of my own calculations.
I am fortunate enough to achieve a Brew House Efficiency of an average 85%.
Personally, and again I may be fortunate, I have never had a "tanin" problem.
 

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