# I keep getting lower than expected original gravity.



## CyberAle (7/11/16)

Hi guys,

Basically, the last few brews I have been getting lower then expected original gravity. When designing my beers, I use beersmith and currently have the efficiency set tot default which is 75%. That being said, this issue could simply be my brewhouse setup is just not up to 75%. Basically, my mash tun is 400 mm stock top, with a false bottom, a heating element at the bottom under temperature control and an accompanying pump that recirculates wort from the bottom near the element back to the top of the mash tun. I use a Brix Refractometer to measure initial gravity and it has been calibrated correctly. Now I have experimented with different thickness of crushed grain to no avail, however, I have no experimented with water to grain ratio, water PH or mashing temperature (the last few brews have been mashed at 67C).

The last brew I did came out with a original gravity of 9.2 Brix (about 1.038 SG) whilst the expected OG in beersmith was supposed to be 1.048. Is it simply a matter of using the wrong brewhouse efficiency in beersmith (and if so how do I improve that efficiency or is it)? or is there something more subtle going on that is causing this lower gravity?

Thanks heaps in advance for any replies.


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## Lyrebird_Cycles (7/11/16)

To help with diagnosis, post the grain bill, total volume and final extract (given as 9.2 oP).

Beersmith can be a bit screwy: I have the opposite problem with it, I have to set my efficiency to 105% to get realistic results while Brewer's Friend has me at only 96%.

Translating to actual extraction removes the influence of the software.


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## MHB (7/11/16)

Looks to me (without a lot more information) that your efficiency is about 60% (well 59.4 if you want to get picky).
Reset to that should get you close to your numbers, then try to figure out why it's so low, there is a very good chance that you are killing a lot of your enzymes with the way you have set up the equipment.
Much longer discussion required.
Mark


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## manticle (7/11/16)

As suggested, work out your real figures and input those into beersmith. It's not meant to be a prophet.

Then if your effieciency is lower than desired, work out where the deficiency is (ingredients, process step, etc) then work out how to improve from there.


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## CyberAle (7/11/16)

Grain Bill:
4 kg of Joe White Pilsner Malt
150 grams of Joe White Vienna Malt

I started with about 25 L, (this is because there is about a 10 L dead space between False Bottom and bottom of the tun, which I think may be a problem in itself), then I fly sparged with 20L at 75C over about 45 minutes.

Yeah my efficiency in beersmith when I reset to match the OG was about 60% or so. I had never thought of possible enzyme killing, it may well be the case as the heating element goes 100% whilst the pump tries to circulate the wort to even distribute the heat. Maybe I should be looking into some sort solid state relay to be able to lower that heating element power.

Thanks guys


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## Dae Tripper (7/11/16)

The Joe White malt is probably half your problem (so I hear), try another brand. Also try not using your element during the mash, you may have to insulate it well.


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## indica86 (8/11/16)

CyberAle said:


> there is about a 10 L dead space


Surely that is the issue?


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## CyberAle (8/11/16)

Under the assumption that it's my element burning off enzyme, can I propose an alteration to my system for a bit scrutiny from you guys? I'm thinking that if I enclose my heating element in some copper or stainless steel piping inside my mash tun and connect it directly to my tap at the bottom of the mash tun which in turn is directly connected to my pump, I could minimise that enzyme scorching? I'm thinking that this way any wort that is directly in contact with the element is quickly pumped away back to the top of the mash?

Yeah Inidca86, I thought the same thing and if that is the case I'm probably gunna have to live with the 60% efficiency until I setup a new mash. I'm hoping that the dead space is not the major problem here, like I thought deadspace has a relatively small affect on efficiency but still obviously something to consider when you want to achieve very high efficiency.

Thanks already for the help this has been enlightening


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## CyberAle (8/11/16)

Dae Tripper, wow I didn't know that? I will definitely try source different malt at the next brew


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## manticle (8/11/16)

Dae Tripper said:


> The Joe White malt is probably half your problem (so I hear), try another brand. Also try not using your element during the mash, you may have to insulate it well.


I believe there was an issue with JW supplying commercial breweries with under spec malt and keeping that under wraps but that doesn't mean you expect lower efficiency as par for the course. While I prefer not to use JW now (just prefer flavour of other brands) I have used them extensively with no issues and recently when hbs was out of gladfield - again no problem.


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## Rocker1986 (8/11/16)

I wouldn't be too concerned with trying to achieve sky high efficiency. Consistency is what you want and although personally I wouldn't be happy with 60%, if it's consistent at least you can design recipes around it easily and work out ways to increase it while still brewing nice beers.

I have the old Crown urn BIAB set up, don't sparge and consistently hit around 75%-78% efficiency on it, aside from beers with big grain bills where it expectedly drops. I wouldn't consider that sky high but it's good enough and it's consistent so designing recipes and having them turn out as expected is easy.


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## Parks (8/11/16)

Dae Tripper said:


> The Joe White malt is probably half your problem (so I hear), try another brand.


Joe White is almost certainly your problem. I was getting shocking efficiency with JW and switched to Barrett Burston and immediately got 10% better brewhouse efficiency.

The main problem with JW is there are massive differences in the grain size, so when you mill some or most of it looks well milled but plenty doesn't get milled.

I know of at least one commercial craft brewer how has switched because of it.

(Edit: that would be very dependent on your mill. I got good efficiency when I double or triple milled but that was more effort when another supplier has a similar product and a similar price without needing to.)


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## damoninja (8/11/16)

Rocker1986 said:


> I wouldn't be too concerned with trying to achieve sky high efficiency. Consistency is what you want and although personally I wouldn't be happy with 60%, if it's consistent at least you can design recipes around it easily and work out ways to increase it while still brewing nice beers.
> 
> I have the old Crown urn BIAB set up, don't sparge and consistently hit around 75%-78% efficiency on it, aside from beers with big grain bills where it expectedly drops. I wouldn't consider that sky high but it's good enough and it's consistent so designing recipes and having them turn out as expected is easy.


Couldn't agree more on the consistency front. 

I have mine dialled in to 75%, I usually get about that and I'm happy to keep it that way. My stuff all gets milled by my LHBS (brewadelaide) and he does a decent crush, lot of people say don't let the LHBS mill but his prices are bonkers good and for an extra 5-10% efficiency it'd take me a lot of brewing to pay for a good mill/rig. 

Maybe it'd make no difference and I'd need to alter something else in my process? Who knows, but I'm content and making good beer so the boss (also me) is happy.


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## CyberAle (8/11/16)

Yeah I am currently in the boat where I am just not happy about a 60% efficiency, I really want to be sitting at around 75% efficiency consistantly. It was one of the reasons I went from an esky to a cylindrical stock pot. I will definitely check out switching grains because honestly I have only ever been using Joe White. I think if I do make these little changes to my mash tun and change grain supplier and I still get around 60% efficiency I will just have to stick with it and aim for consistency. Thanks guys.


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## Meddo (8/11/16)

Rocker1986 said:


> I wouldn't be too concerned with trying to achieve sky high efficiency. Consistency is what you want and although personally I wouldn't be happy with 60%, if it's consistent at least you can design recipes around it easily and work out ways to increase it while still brewing nice beers.
> 
> I have the old Crown urn BIAB set up, don't sparge and consistently hit around 75%-78% efficiency on it, aside from beers with big grain bills where it expectedly drops. I wouldn't consider that sky high but it's good enough and it's consistent so designing recipes and having them turn out as expected is easy.


Rocker I might need to compare notes with you at some point please, as mentioned in that other thread my brewhouse efficiency is about 10-12% lower than yours on a fairly similar system. I'm not too unhappy with 65-ish% overall but I am curious as to where that 10% is going, and wouldn't mind bumping it up a bit if possible.


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## Rocker1986 (8/11/16)

Meddo said:


> Rocker I might need to compare notes with you at some point please, as mentioned in that other thread my brewhouse efficiency is about 10-12% lower than yours on a fairly similar system. I'm not too unhappy with 65-ish% overall but I am curious as to where that 10% is going, and wouldn't mind bumping it up a bit if possible.


No problem mate


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## Matplat (9/11/16)

CyberAle said:


> Under the assumption that it's my element burning off enzyme,


This definitely is not the issue. I run a 1V similar to yours (I use a malt pipe instead of a bag) and I use an stc-1000 (which operates a solenoid so the heater is either 100% or 0%) to control the temp while recirculating. I generally hit 70-75% efficiency...

Oh, and I'm definitely not the only one using an stc-1000 in this manner.


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## contrarian (9/11/16)

There's a few things that could contribute so it's best to be methodical about it and only change one thing at a time. 

The first thing I would check is measurement. How are you measuring your gravity and is this accurate? It might sound dumb but sometimes the simplest solution is the right one. 

If that is accurate work through the things that it could be changing one at a time to see what makes a difference. 

I don't have a recirculating system but is it possible you are getting some channeling? That could be one factor. Is it possible to mash without recirc? If so give that a try. 

Is it water chemistry? I was having problems with pale beers hitting targets and found adding 2-3% acidulated malt to the grain bill made a big difference. If you get different results with dark and light beers this could be the culprit. 

If it is the grain that is simple to test, same recipe, different grain and measure results. 

The downside of this is that you will need to make a fair bit of beer to check all the variables! I hope you have some thirsty mates!


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## CyberAle (9/11/16)

Matplat said:


> This definitely is not the issue. I run a 1V similar to yours (I use a malt pipe instead of a bag) and I use an stc-1000 (which operates a solenoid so the heater is either 100% or 0%) to control the temp while recirculating. I generally hit 70-75% efficiency...
> 
> Oh, and I'm definitely not the only one using an stc-1000 in this manner.


Yeah I run more or less the same system, got an stc-1000 running a relay that contols my heating element at the bottom of my mash, with a tap on the bottom of the stock pot and at the top and a pump circulates the two.


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## CyberAle (9/11/16)

contrarian said:


> There's a few things that could contribute so it's best to be methodical about it and only change one thing at a time.
> 
> The first thing I would check is measurement. How are you measuring your gravity and is this accurate? It might sound dumb but sometimes the simplest solution is the right one.
> 
> ...


Yeah sounds like a plan, I am fairly confident my refractometer is working but hey cant help to check it again

and yeah I guess I will just have to go through all of them! Cheers


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## dannymars (9/11/16)

It would also depend on where you are measuring the temp that controls the STC... You lose some heat through the hoses as the wort is being pumped, the amount of loss also depends on how fast you are pumping it through, how long the hoses are, whether they are insulated or not.


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## CyberAle (9/11/16)

dannymars said:


> It would also depend on where you are measuring the temp that controls the STC... You lose some heat through the hoses as the wort is being pumped, the amount of loss also depends on how fast you are pumping it through, how long the hoses are, whether they are insulated or not.


My temperature probe is located right where the pump comes out at the top right above the grain bed


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## CyberAle (21/11/16)

So I did another brew yesterday, my grain bill was:
5.25 kg of Maris Otter Ale Malt
0.25 kg Vienna Malt

I made this grist with the efficiency in Beersmith at 60%. I mashed at 67C for 60 minutes.

I got a brix reading of 7.5 Plato at 30C after cooling the boiled wort, so we can rule out Joe White malt as the cause. This is ridiculous. The wort though looked very very dark, it should not be that dark considering the grain quantity adjusted at 60%. I beginning to think that maybe my refractometer is stuffed and my mash tun may actually have no efficiency problems at all.


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## MHB (21/11/16)

As you are in Adelaide, it is also worth considering that your water may be quite alkaline, if the pH is too high, you will get low OG's, Dark beer and really rough bitterness.
Worth owning an hydrometer you can trust and making sure your sensors are telling the truth.
Mark


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## Lethaldog (21/11/16)

Also consider the speed of your flow out of the tun and whilst sparging, how long does your transfer from mash tun to kettle take? In my first few all grain brews I had a similar problem then slowed up the flow out of the tun and get 80%+ consistently and a lot of that was with JW so I can't see that being your problem, I'm sure it could be a number of things but there's just one more for you to check[emoji106]


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## Mantis (21/11/16)

Getting low effs too and using JW malts for the base. I did experiment with very slow draining of first runnings which improved things a bit but not worth the wait. Will try different malts in future as well to see if that helps with my setup. Beer still comes out great so not too concerned


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## CyberAle (21/11/16)

Awesome, I think I may go to west end brewery and grab some of their water, as they supply their treated water for free. I have my water pump going at full ball, I will definitely slow down heaps and see if that helps thanks a lot guys


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## Mantis (21/11/16)

Water chemistry helps too, ask them about stuff to put in the mash water to acidify it. This helped me too but I have let it slip as I am happy with my results just using rain water. Try different stuff as we all do but if you get a good result that you like drinking dont get too concerned. Enjoy brewing


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## manticle (21/11/16)

Mantis said:


> Getting low effs too and using JW malts for the base. I did experiment with very slow draining of first runnings which improved things a bit but not worth the wait. Will try different malts in future as well to see if that helps with my setup. Beer still comes out great so not too concerned


OT but welcome back.


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## TheWiggman (22/11/16)

Looking through the thread nobody has talked about volumes (except indica). A simple way to reduce your gravity is to add water to the brew, or dilute it in one part of the process. You're talking about OG and efficiency and forgetting about all the other important stuff.

Eg:

Mash in 5kg grain to 15l water
Sparge until you get 30l in the boiler
If you have 23l in the fermenter at 1.050, you have the same efficiency if you have 29l of 1.040. However if you lose any of that 29l elsewhere in the process and end up with 23l in the fermenter your problem is wastage, _not_ extraction efficiency / getting sugar out of the grain.

How much has been left in the mash tun? If you have 10l of dead space - which seems extreme - you're throwing a fair portion of your sugars away with your grain when you tip out your mash tun on the compost. This is what manticle was hinting at, you need to tune BeerSmith to your system to get the results you want. Prior to that, optimise your system so you're minimising waste and in general supporting good brewing practice so everyone wins.


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## manticle (22/11/16)

Once you get a brand spanking new hydro and check your refrac, go through every step and measure gravity and volume as you go. You need to find out where any weak/suspect points are before you know how or what to fix.

Make sure your thermometer is accurate too.


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## Lyrebird_Cycles (22/11/16)

Lethaldog said:


> Also consider the speed of your flow out of the tun and whilst sparging, how long does your transfer from mash tun to kettle take?





Mantis said:


> I did experiment with very slow draining of first runnings which improved things a bit but not worth the wait.


It's not the flow rate as such that is the problem, it's the differential pressure*, especially the DP of the forerunnings which is the period that sets the bed.




Fore run hook

I've been thinking about controlling this for a while and recently built this device to help. It's held in place by a pulley system which controls the height difference between the top of the hooked portion and the fluid level which in turn defines the differential pressure. The clamp controls the flow rate at the set DP.

I might have to add a short length of clear tube to the vent but if I can keep the DP below 0.3 kPa I won't need to. I use a different method on the main runnings.




*Of course the two are related: for a given average Darcy permeability of the bed one will track the other but that's actually the point: you want low DP and medium permeability which will define the flow rate.


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## CyberAle (22/11/16)

TheWiggman said:


> How much has been left in the mash tun? If you have 10l of dead space - which seems extreme - you're throwing a fair portion of your sugars away with your grain when you tip out your mash tun on the compost.


Sorry, no I don't have 10L deadspace, 10L is just the gap between the false bottom and the base of the Mash Tun. I have very little deadspace, 1-2L max (if I understand correctly deadspace is the wort you cannot mash out because it is not higher then the mash out tap).


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## mckenry (22/11/16)

Terminology is a bit wrong there. Mash out is raising temperature to end conversation. Mash out tap? I think you might mean outlet tap? Dead space is the volume of wort you can't get out post mashing, to the boiler. If it's a single vessel it's therefore 0 but you then have kettle dead space anyway.


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## CyberAle (22/11/16)

Yes thanks, I was struggling to think of the proper term for the outlet tap lol.


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## Rumper (30/11/16)

Not sure on your water to grain ratio but i usually run about 3.1 to 3.2 litres per kilo


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## Jack of all biers (30/11/16)

MHB said:


> As you are in Adelaide, it is also worth considering that your water may be quite alkaline, if the pH is too high, you will get low OG's, Dark beer and really rough bitterness.
> Worth owning an hydrometer you can trust and making sure your sensors are telling the truth.
> Mark


A bit of a myth about Adelaide water being quite alkaline. The average pH values are stated to be between 7.2 and 7.4 for just about all of the Metro area water supplies. The majority of the Adelaide water supply comes from Central which has a recorded 2016 average of 7.4. I measure it out of my tap every brew day (pH meter two point calibrated accurate to 0.01) and consistently get around the 6.8 mark.


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## CyberAle (6/12/16)

Hi guys,

I hit my target gravity last brew with a setting at 70%. I used West End's Brewing water from their Well, had my pump set to about half the flow I usually do, however, the embarrassing thing is, I decided to actually measure with electric scales the measuring container I had been using to measure out my quantities and it turned out that what I had been measuring out to 1 kg on the container was only 750g ! Thus I was only putting 75% of the amount I was planning to. But this is only valid for the last couple brews, before that when I was using 4 kg bags of milled grain from my local store I was still getting a much lower target gravity, so I am suspecting that these 3 changes I made at once all seemed to have fixed my problems. Anyway thanks heaps for all your help! I learned a valuable lesson about being thorough with all my brewing practices.


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## klangers (6/12/16)

Yeah cannot agree more with sorting out your metrology first. I had pretty crap efficiency, until I actually sat down and sorted out my measurements. Turned out it was how I measure my sparge water and I was consistently under-sparging.


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## dblunn (6/12/16)

I have a question regarding sparge technique which is somewhat related to this thread and I would like to hear the views of some of you experienced folk. I have a 3 vessel system with a separate HEX.
Which of the two following scenarios would be better a) sparge until the predetermined volume of sparge liquor has been added to the mash tun, stop adding sparge liquor and then continue draining the mash tun until the required kettle volume is reached (which should coincide with the mash tun running empty) or, b) keep adding sparge liquor to the mash tun until the required kettle volume is reached? Are the two methods equivelent or is one method totally wrong?
Regards, Dave


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## Jack of all biers (6/12/16)

Neither method is wrong. Speed of your sparge (I assume you are fly sparging) is the key. Keep it to around 1L/min and you will have a nice clean sparge (after vorlauf of course) and an improved efficiency.

EDIT - of course the pre-determined volume method works only if your measurements are accurate and temperature compensated for differing volumes etc. It worked for me on my last brew with a mash efficiency of 97.71% into kettle and almost the exact volume I wanted (300ml extra into kettle for a 58L pre-boil, but I added 600ml at the HLT for errors)


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## dblunn (7/12/16)

Thanks for the reply Jack, I have been using the predefined volume in the HLT method as it allows me to add salts and acid to the sparge liquor easily (I use Bru'in water spreadsheet + Beersmith). The only problem is I have to keep a close eye on the level because when the HLT runs dry the HEX overheats (also not great for the pump but there is still quite a bit of water sloshing about in the pump head to keep it lubricated) and last weekend that happend leaving a nasty discoloured section on the HEX element where the water level fell. If possible I will add a second sensor to the HEX housing to keep the water from boiling. I'm not sure there is room though and of course I will need to re-learn my software and make changes to the controller.
Regards, Dave


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## Jack of all biers (7/12/16)

dblunn said:


> Thanks for the reply Jack, I have been using the predefined volume in the HLT method as it allows me to add salts and acid to the sparge liquor easily (I use Bru'in water spreadsheet + Beersmith). The only problem is I have to keep a close eye on the level because when the HLT runs dry the HEX overheats (also not great for the pump but there is still quite a bit of water sloshing about in the pump head to keep it lubricated) and last weekend that happend leaving a nasty discoloured section on the HEX element where the water level fell. If possible I will add a second sensor to the HEX housing to keep the water from boiling. I'm not sure there is room though and of course I will need to re-learn my software and make changes to the controller.
> Regards, Dave


I think you have answered your question for yourself then. Given the lack of difference of resultant volume between the two methods, one is pre-measured and the other measured at the end (and likely more accurate if attention is paid), your only issue would be your salt/acid additions. Without getting into water profiles etc, I will assume that you need to add salts/acid to your sparge water and that your HLT volume is large enough to carry the extra capacity of continuous flow. If this is the case then I'd suggest making up more salted/acidified sparge liquor. The extra it will cost you in salts and acid would be minor compared to the cost of burning/blowing your pump/HEX. 

It all depends on your system set up. Your system sounds like the continuous flow method would be best so as not to damage your equipment. Of course if measuring into the kettle is a problem (which it was for me) then $2-3 for a piece of oak dowel and measure the notches at relevant volume increments is a cheap solution, or a sight glass on your kettle, or a ball valve cut off system to stop the flow/pump/HEX at the required volume setting. The last one would be more expensive, but if being present for the entire process is the problem then it may be the solution. I'm sure there are other ideas out there.

Ah, home brew. Its so simple and cheap to get into and then we want more........


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## jibba02 (7/12/16)

Dae Tripper said:


> The Joe White malt is probably half your problem (so I hear), try another brand. Also try not using your element during the mash, you may have to insulate it well.


Yep had 80kg of the stuff and had the same problem. Now I never use any Jw malt and hit my numbers every time ( give or take)


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## dblunn (7/12/16)

Jack of all biers said:


> I think you have answered your question for yourself then.


Yes, you're right. I had a play with Bru'in water and I can up the sparge volume and it calculates the correct additions for that volume without any effect on the mash additions. Although if I up the mash volume changes pH ect. so that wont work but dough in is quick and it is not a problem to hook up the hose (I underlet) and wait for it to pump in.
Thanks again, Dave


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