Falling short of target OG

[DigitalGiraffe]

Hi guys,

No matter what tweaks I make I seem to be continually falling short of my target gravity. It always seems to be by approx 10points. I checked that my hydrometer was calibrated and even purchased a ATC Refractometer (It was off ebay but calibrated with distilled water).

Currently running the following setup:

50L keggle (insulated and lose approx 1.5degree over 60min mash)
2200w KK element


I've had my LHBS mill my rain twice. No improvement.
Added rice husks to help open up the mash a little (suggested by LHBS).
All my volumes are coonsistent and work out.
Boil off rate 5lph, measured the leftover at the bottom of the keggle.
Tried stirring and leaving mash.

I do use beersmith and I noticed that the default temps for grain/mash tun are 22degrees. I took a reading of my grain on Saturday and it was sitting at 14.8 (I live in Hobart), the mash tun was similar. I changed these temps and the mash temp increased by 0.2 of a degree.

I brewed an English Brown Ale on Saturday just gone, Ended up with 1042 instead of 1053, not huge but I would love to be able to hit my target as its the only part of my brewing that is letting me down. The wort smelt and looked amazing but I just know it will lack the body that I am after. I mashed 4.8kg of grain in 33.67L of water at 67.9 (heated to 72.2 as suggested by beersmith) for 60mins. I resisted temptation to stir the mash as I usually do ever half hour.

Boiled as I normally do. It's by no means a vigorous boil but a substantial rolling boil and will have to suffice till I can afford a 15A circuit installed.

Does anyone have any suggestions? Or notice where I may be going wrong?

Cheers,

Paul

 

[chaositic]

What % efficiency have you set in beersmith?

 

[DigitalGiraffe]

What % efficiency have you set in beersmith?

Tot Efficiency: 72% Est Mash Eff: 85.5%

 

[chaositic]

Are you doing BIAB? Your grain weight and water volume look very BIABish so I'll roll with that. I'd drop your Total efficiency in BS to 65% and do a little sparge on your grain bag. Just hold back a few L before your mash and pour it over or into the grain bag when its lifted. If you have the facility to heat the sparge water then that's a bonus. Then once you start hitting your targets you can look at mash ph, different crush sizes etc and try and up that efficiency a few points at a time. Just my 2c.

 

[DigitalGiraffe]

Are you doing BIAB? Your grain weight and water volume look very BIABish so I'll roll with that. I'd drop your Total efficiency in BS to 65% and do a little sparge on your grain bag. Just hold back a few L before your mash and pour it over or into the grain bag when its lifted. If you have the facility to heat the sparge water then that's a bonus. Then once you start hitting your targets you can look at mash ph, different crush sizes etc and try and up that efficiency a few points at a time. Just my 2c.

Yep BIAB, how did I forget to mention that?! Thanks for the tips MIK-E. I'm hoping to put down another brew this weekend so I'll give that a go. Cheers!

 

[sp0rk]

Have you checked your water pH?

 

[DigitalGiraffe]

Have you checked your water pH?

It's the only thing I haven't checked and had totally forgotten about until you mentioned it. We have really soft water here in Hobart and I know someone who works for TasWater and they said it would likely be around 7.2. Is it worth investing in a pH meter or just grab a container of 5.2 Mash Stabiliser?

 

[Ben1]

Might be a silly question but how did you come to 72% as your target efficiency? If you are consistently under 10 points, then your efficiency is whatever number that comes too. (Beer smith can calculate that). My efficiency for example is 62%. It's not overly efficient but consistent. On a homebrew scale a few extra points makes little difference.

 

[DigitalGiraffe]

Might be a silly question but how did you come to 72% as your target efficiency? If you are consistently under 10 points, then your efficiency is whatever number that comes too. (Beer smith can calculate that). My efficiency for example is 62%. It's not overly efficient but consistent. On a homebrew scale a few extra points makes little difference.

I spent a bit of time earlier in the year reading up on what to put there when setting up profiles but for the life of me can't remember why I settled on that figure. Maybe it was an average.

 

[Spiesy]

I spent a bit of time earlier in the year reading up on what to put there when setting up profiles but for the life of me can't remember why I settled on that figure. Maybe it was an average.

Every system is different, and even then, different batch sizes within a system and different mash profiles and different grain bills can yield different results.

As Ben1 said, set your estimated efficiency a couple of points below what you're currently getting and go from there.

 

[mstrelan]

+1 for lowering your efficiency when building a recipe. Once you hit the your target every time then you can look at improving your efficiency.

 

[Danscraftbeer]

Or you could set up an esky mash tun and do batch sparge. That'll get your efficiencies up.

 

[SBOB]

Or you could set up an esky mash tun and do batch sparge. That'll get your efficiencies up.

I think spending an extra $1 in grain is probably a simpler solution

 

[Beamer]

Gday Digital Giraffe,

When I started BIAB I had the exact same problem running between 63-65%. I found the biggest change besides buying my own mill was my thermometer, I did have a kk analog one then I bought a digital one and found the analog one was about 4 degrees out.

I have now scored my self an esky as a mash tun as Dan has suggested, started doing overnight mashes with batch sparging, and my efficiency has now jumped to 75-77.

 

[Mr B]

Good advice above. Checking temp prob most important right now, and dropping your efficiency a little in recipe.

A little (think 1 -1.5% or so) Acidulated malt might be interesting, likewise using a bit of water adjustment (maybe Calc chloride, Calc sulphate and Mag sulphate). These things gave me 5% or so efficiency boost when I was happy with temp, using rainwater (noting your soft water comment).

 

[MHB]

Just doing a quick rough as calculation I thing you could be getting close to 1.050-1.052 with what is in the post, just making standard assumptions about the grist and type of beer.
For the water to be so bad that it is what is knocking the best part of 20% out of your efficiency is improbable (nearly impossible for anything that comes out of a tap in Australia.
Get a decent thermometer and check your temperatures, I'm quietly confidant that you will be a fair way out!.
For about the 100th time - get a decent glass laboratory thermometer you can trust, use it to calibrate everything else, don't trust anything with batteries or that runs on springs.
Mark

 

[Rocker1986]

Try a coarser crush for your grains too, I BIAB as well and I noticed my efficiency jump up when I started doing this instead of the finer crush.

 

[DigitalGiraffe]

Woah so many responses! You guys are great. Currently I'm running a couple of cheap eBay digital thermometers. One with a spike probe and the other has a long wire with a probe attached that I leave in my mash.

Should I even bother monitoring the temp in my mash? I can't really do anything about can I? I'm probably best to make sure it's accurate prior and post mash. I'll swing by my LHBS and see what they have in the way of thermometers.

I should have full water report tomorrow but if it looks like my pH is sitting around the 7.2 mark should I be using something like 5.2 Mash Stabiliser?

Efficiency dropped to 65 to see how I go.

Thanks again for all your help.

 

[Jens-Kristian]

DigitalGiraffe,

Sorry, I don't want to come across as the 'did you check' guy, but I can't help noting that with 4.8kg of grain and at 72% efficiency, 1044OG is what you'd get out of a 25 litre batch. How large is the batch you're brewing?

You say you mashed the 4.8kg in 33.67l of water. With the boil-off rate of 5l per hour, give and take, that would take you down towards the 25 litre mark and then somehow sounds pretty right to me.

I don't use BeerSmith, but are you sure you've added the right volume of wort in there? Does BeerSmith have separate fields for mash volume and boil volume? I've sometimes made the mistake of putting the final 25l volume into the field in my software that's for mash volume and then not noticed to begin with that my boil volume is set to 20l. As it's the boil volume that is linked to the OG, that obviously inflates the OG beyond what my grain bill allows.

Just a thought, and I may be missing something here, but in my setup I wouldn't expect 4.8kg of grain to get me to 1053 on a 25l batch as that would require that I get 87% efficiency, and in my current setup, I've never gone anywhere north of 80% - usually more in the 70-75% range. Admittedly, my setup is ridiculously basic.

 

[Rocker1986]

It's not so much the water pH that you need to worry about, it's the mash pH. By the time you throw the grains into it, they will drop the pH down anyway. Darker grains drop it further than lighter grains too. I haven't heard a lot of good things about that 5.2 pH stabiliser either.

Beersmith does have separate fields for mash and boil volume.. or rather, it's actually the pre-boil (post-mash) volume and then the batch size itself (volume in the FV). Grain absorption and trub loss need to be taken into account as well; I'd be very surprised if someone was getting 25 litre batches out of a mash in of 33.6 litres with a 5L per hour boil off unless they dumped the entire kettle contents into the cube/FV after the boil. But yes, what batch size are you brewing? And what volume do you have in the keggle before you begin bringing it up to the boil?

My set up is the Crown urn. I normally hit between 75% and 80% overall efficiency with it. I get about 3L per hour boil off, and in order to get 25 litres of trub free wort into the fermenter I need to use a strike volume of about 36 litres water to mash in with.

 

[Jens-Kristian]

I'd be very surprised if someone was getting 25 litre batches out of a mash in of 33.6 litres with a 5L per hour boil off

I entirely agree, but I'm open to whatever may be happening.

 

[DigitalGiraffe]

DigitalGiraffe,

Sorry, I don't want to come across as the 'did you check' guy, but I can't help noting that with 4.8kg of grain and at 72% efficiency, 1044OG is what you'd get out of a 25 litre batch. How large is the batch you're brewing?

You say you mashed the 4.8kg in 33.67l of water. With the boil-off rate of 5l per hour, give and take, that would take you down towards the 25 litre mark and then somehow sounds pretty right to me.

I don't use BeerSmith, but are you sure you've added the right volume of wort in there? Does BeerSmith have separate fields for mash volume and boil volume? I've sometimes made the mistake of putting the final 25l volume into the field in my software that's for mash volume and then not noticed to begin with that my boil volume is set to 20l. As it's the boil volume that is linked to the OG, that obviously inflates the OG beyond what my grain bill allows.

Just a thought, and I may be missing something here, but in my setup I wouldn't expect 4.8kg of grain to get me to 1053 on a 25l batch as that would require that I get 87% efficiency, and in my current setup, I've never gone anywhere north of 80% - usually more in the 70-75% range. Admittedly, my setup is ridiculously basic.

Don't be sorry, I'd be more than happy for someone to point out I was doing some stupid so it could be easily resolved.

Generally I aim for a 21L batch (Usually lose a couple of litres at the bottom with trub) which gives me 19L to bottle. I also lose about 3-4L in the bottom of the keggle.

Beersmith autocalculates the boil volume and it's listing 29.96L if I have 5LPH boil off, Lose 3L too keggle, 2L loss in Fermenter and want a batch of 21L.

So perhaps my grain bill isn't large enough? Whats the average absorption rate?

 

[DigitalGiraffe]

I've just had confirmation that my water pH is generally 7.2 but can vary between 6.9-7.2.

I also re-entered the recipe for my last brew into beersmith with Tot Efficiency now set to 65%. I did also notice that the recipe was for 20L and my default was 21L so that extra water may explain why I missed my target on this brew but not my others. The total volume of water required has dropped from 33.65 down to 31.85 for my 4.8kg grain bill.

I'll check the batch sizes against the original recipes tonight.

 

[Rocker1986]

One litre extra won't throw your OG out by 11 points or whatever it was. The total water sounds about right, with my urn for 21 litre batches I use about 32 litres at the beginning. You don't have to have Beersmith automatically calculate the boil volume either. I edited it to suit my own system once I got a few batches done and worked out what it actually was. I brew two different batch sizes as well, 21 and 25 litres, depending on whether I want some surplus bottles or not. I have two separate profiles set up in Beersmith for these.

My last batch that I kegged was also a 21 litre size batch; it used a 3.73kg grain bill and I ended up with an OG of 1.0425; giving me 76.2% overall efficiency (I actually got 22L into the FV making the efficiency 80%, but intended size was 21L so I went with that). Basically exactly what you got from a kg less of grain. I think your volumes in Beersmith sound ok, but there's something happening in the actual brewing process somewhere that is causing issues with extracting the sugars from the grains.

I think having the grain milled too fine is detrimental in BIAB and that double milling is unnecessary, however, that is purely based on my own personal experiences. I don't have any proper research/data to confirm it - that's just what happened in my situation. As soon as I went to a coarse crush with very little grain flour, my efficiency improved. There were other things I did, such as stirring the mash a bit every so often, and discovering that my hydrometer was reading 2 points low as well. I've experimented on the last 2 or 3 batches with not stirring the mash at all except at dough in and during temperature ramp ups, and it hasn't really made any difference. So maybe the stirring isn't really necessary.

I haven't done much at all in regard to mash pH, mainly because I have no problems with the brewing process or how the beers turn out in the glass, so I figure it must be sitting pretty much where it should be. Would be interesting to find out what it really is though, might have to look into a decent pH meter at some point.

 

[TheWiggman]

You're missing one critical measure here - volume. Starting volume is fairly relevent, but when you're calculating brewhouse efficiency you're talking about how much ends up in the fermenter at a given gravity. That is to say that by increasing the amount of liquid you extract from the kettle you'll immediately increase the efficiency.
What was your volume in the fermenter? How much were you leaving behind in the kettle? What was your pre-boil gravity?

 

[MHB]

Apology time

Just doing a quick rough as calculation I thing you could be getting close to 1.050-1.052 with what is in the post, just making standard assumptions about the grist and type of beer.
For the water to be so bad that it is what is knocking the best part of 20% out of your efficiency is improbable (nearly impossible for anything that comes out of a tap in Australia.
Get a decent thermometer and check your temperatures, I'm quietly confidant that you will be a fair way out!.
For about the 100th time - get a decent glass laboratory thermometer you can trust, use it to calibrate everything else, don't trust anything with batteries or that runs on springs.
Mark

I didn't take out Brewery efficiency, that's about the theoretical yield, so with your grain bill, in the amount of water you mashed into - without a sparge, what you got is pretty much on the money.
So in short you aren't doing anything too wrong, you just need more malt to get a higher gravity.

I'm not apologising for suggesting you get a good glass lab thermometer, that's still a very good idea.
As mentioned above it is a good idea to do a work back from "How much beer you want" adding on all the losses, Left in the fermenter (maybe 1L), Left in the kettle 5-10% (measure it), Evaporation during the boil (you said 5L/h), Absorbed by the malt (about 0.9L/kg so 4.8kg*0.9=4.32L), splashing, samples, evaporation during mashing... (about 2% of mash water).
Should give you a very good idea of how much water you need to start with.
Mark

 

[DigitalGiraffe]

Apology time
I didn't take out Brewery efficiency, that's about the theoretical yield, so with your grain bill, in the amount of water you mashed into - without a sparge, what you got is pretty much on the money.
So in short you aren't doing anything too wrong, you just need more malt to get a higher gravity.

I'm not apologising for suggesting you get a good glass lab thermometer, that's still a very good idea.
As mentioned above it is a good idea to do a work back from "How much beer you want" adding on all the losses, Left in the fermenter (maybe 1L), Left in the kettle 5-10% (measure it), Evaporation during the boil (you said 5L/h), Absorbed by the malt (about 0.9L/kg so 4.8kg*0.9=4.32L), splashing, samples, evaporation during mashing... (about 2% of mash water).
Should give you a very good idea of how much water you need to start with.
Mark

No need for apologies. I'm stoked and thankful that everyone has offered so much help. Bunch of legends!

I will be sourcing myself a decent thermometer. You can never have too much brew gear right?

 

[Ben1]

Keep at it with beer smith. It's terribly confusing and counter intuitive to set up but once you get your head around it, it makes recipe formulation a breeze.

The key with efficiency is to not 'aim' for a certain efficiency but instead measure everything, plug it into beer smith and it will tell you your efficiency. If you then use that number going forward your beers should be spot on.

There have been some great suggestions to improve your efficiency but at this stage you want consistency rather than a really high number.

Efficiency just means how much grain you require to get a certain OG. If you have a low but consistent efficiency, you can just buy a little more grain (which beer smith will tell you the amounts)

 

[DigitalGiraffe]

I'm planning a brew for this weekend and have lowered the efficiency in beersmith as suggested. Hoping to grab a decent thermometer by the weekend also.

This is the brew I'll be putting down and have scaled it to 21L using beer smith.

https://www.brewtoad.com/recipes/mountain-goat-fancy-pants-clone-1

Here are the numbers that beer smith has given me. Do they sound about right?



Recipe: Mountain Goat Fancy Pants 40L scaled - 18/7/16
Brewer: Sparrows Talon
Asst Brewer:
Style: American Amber Ale
TYPE: All Grain
Taste: (30.0)

Recipe Specifications
--------------------------
Boil Size: 29.96 l
Post Boil Volume: 24.96 l
Batch Size (fermenter): 21.00 l
Bottling Volume: 19.00 l
Estimated OG: 1.060 SG
Estimated Color: 17.5 SRM
Estimated IBU: 33.7 IBUs
Brewhouse Efficiency: 62.00 %
Est Mash Efficiency: 70.9 %
Boil Time: 60 Minutes

Ingredients:
------------
Amt Name Type # %/IBU
4.94 kg Pale Malt, Traditional Ale (Joe White) 75.2 %
0.43 kg Caramel/Crystal Malt - 60L (60.0 SRM) 6.5 %
0.39 kg Munich, Light (Joe White) (9.0 SRM) 5.9 %
0.39 kg Cara-Pils/Dextrine (2.0 SRM) 5.9 %
0.28 kg Carared (20.0 SRM) 4.3 %
0.14 kg Chocolate Malt (Joe White) (381.0 SRM) 2.2 %
10.79 g Cascade [5.50 %] - Boil 60.0 min 6.4 IBUs
10.79 g Galaxy [14.00 %] - Boil 60.0 min 16.2 IBUs
10.79 g Cascade [5.50 %] - Boil 15.0 min 3.2 IBUs
10.79 g Galaxy [14.00 %] - Boil 15.0 min 8.0 IBUs
1.0 pkg White Labs California Ale
11.00 g Cascade [5.50 %] - Dry Hop 7.0 Days 0.0 IBUs
11.00 g Galaxy [14.00 %] - Dry Hop 7.0 Days 0.0 IBUs


Mash Schedule: 001 BIAB Mash
Total Grain Weight: 6.57 kg
----------------------------
Name Description Step Temperature Step Time
Mash Step Add 33.98 l of water at 73.1 C 67.8 C 60 min

Sparge: If steeping, remove grains, and prepare to boil wort

 

[Rocker1986]

I remember reading on here recently that someone had been having issues with Joe White malts and lower efficiency than with other brands of base malt. I wonder if that might be something to do with it? :unsure: I haven't used JW for a long time so I don't know what it's like now. Back then it was fine though.