What to do when your mash is too efficient?

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What to do when your mash is too efficient?

Post by Manngold » Sun May 21, 2017 7:36 pm

Hi all,

The past two brews have seen my efficiency being too good. I have been aiming for 1.050, but have ended up with 1.062 each time, this is simply far too strong for me to drink as the session pale imhad wanted. It is the same recipe for both, Dennis Kings Galaxy Delight from the Malt Miller.

Could I draw off about 3l and top up with water, adding the other 3l to a demijohn? If so, other than lowering the gravity and abv, what other impact would it have?

Thanks all

gazjcollins

Re: What to do when your mash is too efficient?

Post by gazjcollins » Sun May 21, 2017 10:54 pm

Manngold wrote:Hi all,

The past two brews have seen my efficiency being too good. I have been aiming for 1.050, but have ended up with 1.062 each time, this is simply far too strong for me to drink as the session pale imhad wanted. It is the same recipe for both, Dennis Kings Galaxy Delight from the Malt Miller.

Could I draw off about 3l and top up with water, adding the other 3l to a demijohn? If so, other than lowering the gravity and abv, what other impact would it have?

Thanks all
Hi Manngold.

First of all - wish my efficiency was too good!

You could simply water your wort down until you achieve the efficiency but I would suggest that you do this pre-boil.

Do you use something like BeerSmith to calculate your recipes at all? If so, this should give you a pre-boil gravity to aim for. It also has a calculator that allows you to work out how much extra water you would need to reduce your gravity accordingly.

Ultimately, you are going to end up with more beer than expected. Shame!

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Re: What to do when your mash is too efficient?

Post by Jim » Mon May 22, 2017 7:55 am

The main problem with liquoring back (to use the technical term for watering your wort down :) ) is that you also dilute the hop oils and therefore reduce the bitterness slightly. Probably the only thing you can do though, apart from feeding the results of this back into your brewhouse calculations for next time.
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Re: What to do when your mash is too efficient?

Post by Manngold » Mon May 22, 2017 8:07 am

Thanks both. So in future, it is best for me to take a gravity reading after the mash and before boil so I can add more water as necessary? Does the boil change the gravity at all.

Gaz, I don't use Beersmith at the moment, just going by a simple recipe sheet that I follow for each brew. Could the increase in gravity also be down to me mashing for between 90 - 120 minutes. I read another thread about a 60 minute mash, maybe I should follow this.

Thanks again.

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Re: What to do when your mash is too efficient?

Post by guypettigrew » Mon May 22, 2017 8:18 am

I've just run the numbers through Graham Wheeler's 'Beer Engine'. If you're getting a gravity of 1.062 in 23 litres from the ingredients supplied in the Malt Miller kit would mean your overall efficiency is 95%. That efficiency is incredible!

Or, alternatively, you're ending up with about 18 litres of beer instead of 23, but with an efficiency of about 75%.

If it's the latter then, as suggested earlier, add extra liquor during the boil.

Your length of mash time shouldn't affect the efficiency.

Guy

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Re: What to do when your mash is too efficient?

Post by Kev888 » Mon May 22, 2017 9:21 am

You don't mention what your efficiency is, but it won't be too good. Either your predicted efficiency will be too low (therefore you will be using excessive grain for your system/process) or your volumes will be coming up short (concentrating the sugars into higher gravity), or a combination of them both.

If you are just following a recipe sheet which isn't customised to your own particular situation then it is unlikely to deliver the exact same results as it did for the author on their system and process. Ideally you would build up a picture of the mash and brew-house efficiencies you personally achieve and so be able to predict and alter recipes accordingly.

A key part of this is keeping records. Record all your ingredients weights, liquor volumes, and wort volume and gravity pre-boil, post boil and volume in the fermenter. This will let you (or software) calculate the approximate mash efficiency and subsequent volume losses included in the brew-house efficiency.

To answer your other question, during the boil you will lose water to evaporation but not sugars, so these become more concentrated and the gravity increases as volume decreases. The boil-off rate (percentage reduction in volume during the boil) is one of the things you need to know in order to judge liquor volumes correctly, unless you intend to top up the boiler to compensate.
Kev

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Re: What to do when your mash is too efficient?

Post by guypettigrew » Mon May 22, 2017 11:50 am

Hi Kev--the first post explains manngold is using the Malt Miller's 'Dennis King's Galaxy Delight' all grain kit. This uses 5kg of grain and should (according to the MM site) give 23 litres at about 1.050.

This would indeed be the case if the efficiency was about 75%.

My guess is manngold is losing too much liquid during the boil. As I said, to get a gravity of 1.062 he'd have to end up with about 18 litres rather than 23.

Guy

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Re: What to do when your mash is too efficient?

Post by Kev888 » Mon May 22, 2017 1:33 pm

Hi Guy. Yes, I agree that is very likely the case (the efficiency could even be appalling and get that same result).

Though IMO it is impossible to be certain where the gains and losses are without some of the volume and gravity figures I suggested. The recipe assumes roughly 74% or 75% brewhouse efficiency for its intended OG, which is perfectly respectable but not an upper limit - the OP could potentially be getting greater overall efficiency than the recipe expects (at least in part, its unlikely the efficiency would be 'so' much better as to account for the whole rise in gravity - that would be over 90% brewhouse..).
Kev

AnthonyUK

Re: What to do when your mash is too efficient?

Post by AnthonyUK » Mon May 22, 2017 1:56 pm

gazjcollins wrote:First of all - wish my efficiency was too good!
Really? Higher efficiency does not equal better beer unless you are looking for quantity over quality :wink:

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Re: What to do when your mash is too efficient?

Post by Manngold » Mon May 22, 2017 2:38 pm

Thanks all.

Guy and Kev, to answer your question, I must confess something. I use the BIAB method and so do a full volume mash, in 36L of Liquor (thanks Jim for pointing me in the correct use of terminology). I am normally left with approx 24L after a 90 minute boil. My system has a 2.4kw heating element.

Kev, I thought that was the case with the boil evaporating water and not sugar, but was not 100% sure.

Do you have any general tips for being more consistent with hitting the intended O.G on the day (I used to never have this problem and mashed, used the same amount of liquor, no sparge, etc as before - however the last three brews have been my first in over two years). I might just cave in and buy the Grainfather!

Thanks all

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Re: What to do when your mash is too efficient?

Post by guypettigrew » Mon May 22, 2017 3:11 pm

This is a blindingly obvious question, but have you checked your hydrometer? Getting 95+% efficiency is beyond the bounds of possibility, I'd have thought.

Guy

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Re: What to do when your mash is too efficient?

Post by Jocky » Mon May 22, 2017 3:33 pm

guypettigrew wrote:This is a blindingly obvious question, but have you checked your hydrometer? Getting 95+% efficiency is beyond the bounds of possibility, I'd have thought.

Guy
Yeah, I'd second that. The efficiency seems rather too high. If you've ever dropped the hydrometer, or put it in hot wort then there's every chance the paper insert that has the gravity scale on it has been shifted out of place.

Stick your hydrometer in tap water (@ 20c) and check that it reads 1.000 or at least within a couple of points.
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Re: What to do when your mash is too efficient?

Post by Manngold » Mon May 22, 2017 3:34 pm

Hi Guy, yes, I also thought the same so tested it in water and it came up at 1.000. I will get another hydrometer this evening and try to test it out.

Thanks for the suggestion

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Re: What to do when your mash is too efficient?

Post by Kev888 » Mon May 22, 2017 10:22 pm

It would also be worth checking your volumes - don't rely on the printed scale on fermenters, for instance, as they can be sloppy. Similarly (to a lesser degree) with checking thermometers, since if the wort wasn't at the hydrometer's calibrated temperature that will also cause an error in gravity reading. This may be a combination of smaller things rather than one major oddity. I would also say to check your weighing scales, but it sounds like you bought the ingredients ready weighed, unless the supplier has been generous.

BIAB tends to do well for minimising loss of sugars to dead-space and grain retention, so the brew-house efficiency is still fairly good relative to its mash efficiency. 'But' by my calculations if all were as it should be and your volumes are correct, then you would have to be getting over 92% brewhouse efficiency... With full-volume mashes and normal amounts of wort retained by the grain you would have to exceed the potential yield of the grain to reach that for mash efficiency, let alone brewhouse efficiency, so its 'deeply' probable there is an error in some measurement somewhere.
Kev

gazjcollins

Re: What to do when your mash is too efficient?

Post by gazjcollins » Mon May 22, 2017 10:30 pm

AnthonyUK wrote:
gazjcollins wrote:First of all - wish my efficiency was too good!
Really? Higher efficiency does not equal better beer unless you are looking for quantity over quality :wink:
I aim for quantity AND quality.... naturally...Image

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