I keep getting lower than expected original gravity.

[CyberAle]

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.

 

[Lyrebird_Cycles]

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.

 

[MHB]

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

 

[manticle]

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.

 

[CyberAle]

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

 

[Dae Tripper]

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.

 

[indica86]

there is about a 10 L dead space

Surely that is the issue?

 

[CyberAle]

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

 

[CyberAle]

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

 

[manticle]

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.

 

[Rocker1986]

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.

 

[Parks]

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.)

 

[damoninja]

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.

 

[CyberAle]

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.

 

[Meddo]

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.

 

[Rocker1986]

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

 

[Matplat]

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.

 

[contrarian]

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!

 

[CyberAle]

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.

 

[CyberAle]

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!

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