First AG - low efficiency

[mofox1]

Hit my first all grain yesterday and was a bit suprised at the low efficiency... still wondering what went (slightly) pear shaped.

According to beer smith, I should have got an OG of about 1.045 but I ended up with 1.038. Is a 7 point difference enough to worry about?

Simple enough recipe (20L batch):
4.00 kg Pale Malt (Joe White)
0.22 kg Dark Crystal (220 EBC)
0.20 kg Crystal (50 EBC)

Hopped with Amarillo, 25g for 40min, 15g @ flameout & 10g dry hopped.

Cube chilled (15L) and added 5L cold to the fermenter.

Mash/boil details:

Mashed in with 11L, and mashed out/batch sparged with another 11L. Temp during mash started at 67deg C and finished at 64deg C over 70 mins. Mash out was ~75deg C.

The mash tun has less than a cup of dead space, and I reckon I lost about 1L for kettle trub and/or floor spillage (also a first attempt for siphoning...).

I didn't do a starch test, or take the SG of the first runnings or pre-boil, which in retrospect may have been useful now. I also don't know exactly how much I ended up with pre-boil, except that post boil was around 14 - 15 L (had to add ~1L boiled water to the cube and squeeze the buggery out of it as it holds 16L hot).

So the question is - what would account for the low OG? As far as I can tell, it should only be poor conversion, since there wasn't too much 'unrecoverable' liquid anywhere.

The mash tun has a square 36x36 cm footprint (40L esky), so maybe as a small batch the low grain depth may have been an issue?

Any tips would be appreciated!

Cheers,
Mick

 

[geneabovill]

Heat has an effect on hydrometer readings, so if you took your sample while it was hot, you'll get a dodgy number - can be calculated using online calcs, or your brewing software may have a calc for that.

Having said that, I got really bad efficiency on my first AG too. From memory I was after OG of 1.058 and ended up with 1.037 or something. Bumped the gravity up by boiling some DME and water and adding to the fermenter.

Punch all your numbers back into your software and see what you get back, and account for that in your next batch.

Takes a few brews to dial in your system and work out all its gremlins - kinda like two stroke engines. They're all different.

 

[mxd]

without doing the arithmetic what efficiency did you plan on and what did you get ?

 

[TheWiggman]

Don't fret, all is not lost, you've got a long road ahead of you and be thankful you've ended up with wort in the fermenter.
The first thing I'd work on with AG is taking gravity readings. If you knew your first runnings, sparge and pre-boil you'd probably know where your problem is (if any). As above confirm the hydrometer* is good first and rule that out.
Assuming it is, 1.038 does seem low for a... 16 batch? I did 4.2kg of malt recently with about 28 l in the boiler and it was about 1.036 pre-boil. Do the advice above first. Otherwise maybe a coarse or inconsistent milling could be at fault. Or maybe you rushed the batch sparge, but I don't think it would make that much of a difference.

Ed: *or refractometer. Highly recommended.

 

[Back Yard Brewer]

Heat has an effect on hydrometer readings, so if you took your sample while it was hot, you'll get a dodgy number - can be calculated using online calcs, or your brewing software may have a calc for that.

Having said that, I got really bad efficiency on my first AG too. From memory I was after OG of 1.058 and ended up with 1.037 or something. Bumped the gravity up by boiling some DME and water and adding to the fermenter.

Punch all your numbers back into your software and see what you get back, and account for that in your next batch.

Takes a few brews to dial in your system and work out all its gremlins - kinda like two stroke engines. They're all different.

It took me a number of batches to get my system down pat. Now its a walk in the park. I would compare it to buying a new car, get accustomed to how the system works tweak it into beersmith as you go.

Andy...

 

[mofox1]

No hot samples, geneabovill - just the one going into the fermenter.

Hydrometer *should* be good. Done a heap of extract & partials and haven't had an issue. Then again, haven't tested its calibration it either - it reads 1.000 for water, but who knows if the upper end is good. So... will take the advice on the refractometer.

I started with a ~70% brewhouse efficiency in beer smith, in order to end up with 1.038 the efficiency would need to be < 60%... seems pretty low.

On the other hand, my mash tun didn't leak and no hoses popped off while I wasn't looking. So that's a win.

 

[mofox1]

So "tweaking beersmith", is that a matter of adjusting the brewhouse efficiency & the various losses? Does anything else have a large impact?

New to beer smith too.

cheers,
Mick

 

[thebigwilk]

How did the grain crush look and who did it ?
Maybe give the mash a stir every 20 min.
If your water PH is to high you will get low enzyme activity try 2ml lactic acid next time.
mash for longer time I if possible go 90 min

Just a few ideas for next brew.

 

[Tony]

Generlly low efficiency can be attributed to a few things:

1. Too course a crush
2. sparged too fast
3. combination of 1 and 2
4. too fine a crush and sparge water channels or bypasses mash.
5. not enough grain (usually caused by weighing grain out after 6 or more beers)
6. Old grain or pre cracked grain that sat around in the HBS too long (enzyme degridation)

When you sparge, your not washing the residual sugars off the grain in the mash, your trying to draw it out. The primary mash will only ever get to a certain gravity becasue the water saturates with sugars. You drain this out and sparge to try and get the remaining sugars and this is where efficiency points can be gained or lost with ease. Its also the bit that improves with practice, experience, knowledge and patience.

I used to batch sparge with a single batch by filling the mash ton with 80 deg water and giving it a really good mix to expose all the grain to the virgin water. I then let it sit for 5 min to let it settle on the false bottom and recirced it untill it cleared up and them pumped to the kettle. If i still needed a bit of volume in the boil i just topped up with water. Getting greedy with the sparge will only extract tannins and other bad things as the mash bed PH will have rissen with all the sugars gone.

I remember visiting a local brewer who had asked me to come check out their brew rig. I took one look at the grist which was being crushed by a local HBS and said "do you get better than 60% efficinecy with this?
He said he was getting 58% and couldnt work out what was going on. I told him to buy a grain mill or ask for it to be cracked finer. It was very course.

Also, dont buy or use grain that has not been freshly cracked. After a week, its on a fast down hill slide.

Hope this helps

Cheers

 

[pat86]

My first batch was about the same, I think it came out around 60% but I was still happy! and it did turn out to be one of my better beers - just a mid strength instead came out at 3.9% abv% hah. I also learned that an extra 50grams of carafa2 can make a pretty noticeable difference to a batch, so productive all round.

Next try my efficiency was up to more respectable levels ~75%, but I'm more worried about just making repeatable good beer which I still have a tonne to work out!

 

[mofox1]

Good tips. Did stir the mash a couple of times when checking temps. Did notice some channelling when sparging, but the end leavings looked pretty thin.

But.... There were a *lot* of whole grains in there. Should I be seeing a lot a whole grains in there, or should I be seeing a different LHBS?

cheers,
Mick

 

[kevo]

Take lots of notes in these early batches, about everything - use these to guide future tweaks too...

 

[Yob]

Mostly intact husk yes... Whole grains? No..

Don't sack the lhbs, just ask for a better service from them.

 

[Back Yard Brewer]

So "tweaking beersmith", is that a matter of adjusting the brewhouse efficiency & the various losses? Does anything else have a large impact?

New to beer smith too.

cheers,
Mick

Basically, yes. Well to me it does.
evaporation
loss to trub
shrinkage after chilling

On another note, do you fly or batch sparge? Not that I want to get into another discussion on the best method... Just something to think about as well.

BYB

 

[ekul]

Are you making a high gravity wort that you can add water to later in the fermenter? I notice you have a 15L cube and then add 5L to the fermenter later. I find when i try brew higher gravity beers i lose efficiency as well.

 

[mofox1]

Basically, yes. Well to me it does.
evaporation
loss to trub
shrinkage after chilling

On another note, do you fly or batch sparge? Not that I want to get into another discussion on the best method... Just something to think about as well.

BYB

Batch (single, after draining completely). Easiest for minimal setup. Next time I'll probably do two sparges.

Are you making a high gravity wort that you can add water to later in the fermenter? I notice you have a 15L cube and then add 5L to the fermenter later. I find when i try brew higher gravity beers i lose efficiency as well.

Yes. This was probably the killer. Unless I'm using it wrong (highly likely) Beer Smith doesn't seem to compensate for different sparge methods or volumes when working out the OG.

I've got some copper coil coming from the US, and I'm on the lookout for a big boil pot, so hopefully I won't have the cube size issue next time.

Any recommendations for the boil pot? Currently looking at craftbrewer in qld. Comes predrilled for weldless tap fitting, 70L at $190 (incl postage to Melbourne).

Cheers,
Mick

 

[Jerry]

Any recommendations for the boil pot? Currently looking at craftbrewer in qld. Comes predrilled for weldless tap fitting, 70L at $190 (incl postage to Melbourne).
Cheers,
Mick

G'day Mick,
I have a 70 ltr Craftbrewer pot. I use it as my mash tun but have also used it as my kettle a few times when I've done the occasional double batch.

Can certainly recommend them.

Cheers,

Scott

 

[mofox1]

G'day Mick,
I have a 70 ltr Craftbrewer pot. I use it as my mash tun but have also used it as my kettle a few times when I've done the occasional double batch.

Can certainly recommend them.

Cheers,

Scott

Nice. Well, they've come up trumps so far for new pots. I would definately *like* to pay less than $200 (incl shipping, hole drilling)... but I dont think it's going to happen! :lol:

Mick

 

[mofox1]

Mostly intact husk yes... Whole grains? No..

Don't sack the lhbs, just ask for a better service from them.

So it looked a bit like the second image here http://www.brewersfriend.com/2009/03/28/best-grind-setting-for-grains/

Hmm. Or I could just post the pic.

Apparently this is listed under the bad category... so enough said.

Mick

 

[ekul]

I think your issue came from trying to get a high gravity wort plus the ****** crush. When i do high gravity brews i lose a lot of efficiency.

Depending on what size you want to go i would recommend an aluminium pot. I got a solid140L one from ebay for $200 delivered. I biab with it and usually do triple batches (69L). I can get 5x20L cubes but who wants to drink 5 cubes of the same beer!?
Aluminium is great because it sucks the heat up from the burner, its cheap and really light.