Efficiency ain't everything . . .but

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ajmuzza

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. . . jees a couple more points would be nice.

So I've done about 9 x 40L Crown Urn BIAB brews and my mash efficiency has been in the shitter (but constant) @ 51-52%. Currently using about 5.4kgs of grain to generate 17L of wort (excluding 2L loss to trub). Relevant information:

1. I have used both an old CB BIAB bag and swiss voile;
2. Generally mash in at anywhere between 65 -67 dpeending on the brew. Mash for 60mins and generally loose about 1.5 degrees over that time (even though the urn is insulated with comressed foam and lagged with a doona) so most times I give it a blast at 30mins to get maintain the temp.
3. Pen thermometer has been calibrated and is accurate to 0.5 degree.
4. I buy my grain milled from the Daves HBS in Sydney. It's a middle of the road mill ie not superfine or super coarse.
5. I don't sparge.
6. I've tried a mashout and it didn't make a lot of difference (couple of %).
7. I check my pre-boil SG and reconcile this with the post-boil no chilled wort prior to pitching.
8. Never done a starch conversion test.

Buggered if i know what's going on. I'd like to increase the brew size or brew some higher SG brews, but with the current efficiency and quantity of grain, I'd need upward of 6+kg of grain - try pulling that bag by yourself one handed.

I understand that i should conservatively be getting anywhere from 60-70% without a sparge or mashout.

Any suggestions on how I might analyse or fix this would be greatly appreciated.

Cheers
 
you could try a finer crush
 
Just standard Sydney tap water. Not sure what the source is for the lower north shore in Sydney. Have not looked at my mash ph, but I didn't think (admittedly without any basis) Sydney tap was not overly hard or soft. Maybe there are some other Sydney brewers out there how have investigated?
 
mxd said:
you could try a finer crush
Spoke to the LHBS about that. They agreed that you could go finer, but, putting aside the difficulties in changing their set up, that they found that what they were doing suited the majority ie they weren't being requested to provide a finer crush by anyone else.
 
When I lived in Sydney, I used malt from Dave's where he had crushed it and had 70%+ efficiency no problems using BIAB.
 
GalBrew said:
When I lived in Sydney, I used malt from Dave's where he had crushed it and had 70%+ efficiency no problems using BIAB.
Yep. I've heard similiar reports. Given that i'm still on my BIAB apprenticeship, I'm sure there are other issues than the crush.
 
Do you give the grain a good stir when you mash in to ensure that there are no dough balls? When I first started I found that a good stir inside the bag made a massive difference. This is also why a mashout can help when BIABing. Whilst ramping up to mashout temp I constantly stir the grain, breaking up any clumps and exposing all of the grain to the wort.
 
Is your brew software giving you an accurate expected OG? What software are you using?

What are you using to measure your OG? Do you need to make a temperature correction?
 
I assume because you're doing BIAB that you liquor-to-grist ratio is quite high and that you don't have any dry pockets.

60 min should be more than long enough to convert high diastatic mashes such as those with a majority of pale or pils malt.

You said you lose about 2 L to trub which isn't bad, but how much are you actually getting from the grain bag in the first place? Let's say you mash in with 30 L and you use 5.4 kg of grain. You would typically lose 3 - 6 L to grain absorption leaving you with 24 - 27 L. If you're losing much more than that then that could be the problem - you're converting sugars but not getting them out of the grains.


danestead said:
What are you using to measure your OG? Do you need to make a temperature correction?
Good point, many people have fallen into that trap before.

PS. Just to make sure you are actually getting proper conversion it's probably worth getting some iodine like Betadine or something and do a starch test. Cheap for piece of mind.
 
some of the guys get them to run it though the mill twice, maybe that's an option to try,

some good stirring every 10 to 15 min may help
 
Why are you only getting 17L. I would up the grain/water ratio if your not sparging.
 
have you tried an extended mash? When i mash for 60 mins my eff is way down. Up it to 90mins or more (i often mash overnight) i get 75-80%
 
Some of these steps are probably contentious and perhaps even unrelated to efficiency but here's what I do to hit 70-75% for 1055-1060 OG:

1. Massive amounts of stirring prior to puttng the lid and insulation on (putting the beer to sleep as my 3 year old calls it)
2. Couple of tsp of Gypsum in the water before adding grain. I'm on sydney water (prospect reseviour)
3. Raising temp to 78 before lifting the bag out
4. Squeeze the crap out of the bag. I know lots and lots of people say this is a real no no.
5. I use about 37-38 litires of water for 6.4 kg of grain
6. 90 minute mash. Sometimes even longer if I get distracted

Milling doesn't seem to affect things too much for me. I've had the same success with milled grain from Absolute Homebrew as my own finer milling

I also don't sparge but might look into one day
 
Squeezing the bag is a good point, If your bag is retaining a lot of wort, then that is going to affect your efficiency quite a bit. When I BIABed I squeezed the bag (which as mentioned above is a contentious topic in itself), you would be amazed how much you can get out.
 
I would ask nicely, if the brew shop can put the grain through twice. It may help, but without a pic of the crush I'm guessing.

Why don't you sparge. Even a "hose sparge" will help.
Hose Sparge: It's what I started doing in my BIAB days, and still do on my 1V. Use a nossle on the garden hose that has a gentle shower setting and spray the draining grain with fresh cold water to get your pre-boil volume, allowing it will drain for a sec to get the final volume. Yes cold water works a lot better than you expect. I hit 85% pre-boil eff using this method.

As mentioned prior, give the grain a good stir if you don't recirculate via a pump.
 
dainesr said:
Some of these steps are probably contentious and perhaps even unrelated to efficiency but here's what I do to hit 70-75% for 1055-1060 OG:

1. Massive amounts of stirring prior to puttng the lid and insulation on (putting the beer to sleep as my 3 year old calls it)
2. Couple of tsp of Gypsum in the water before adding grain. I'm on sydney water (prospect reseviour)
3. Raising temp to 78 before lifting the bag out
4. Squeeze the crap out of the bag. I know lots and lots of people say this is a real no no.
5. I use about 37-38 litires of water for 6.4 kg of grain
6. 90 minute mash. Sometimes even longer if I get distracted

Milling doesn't seem to affect things too much for me. I've had the same success with milled grain from Absolute Homebrew as my own finer milling

I also don't sparge but might look into one day
I definitely agree with point 4 - I found that squeezing the bejesus out of the bag really helped to increase my efficiency (although I didn't know that this was not recommended)
 
+1 for asking them to mill your grain twice - no need for them to adjust their mill settings. I'd also try a sparge.
 
there really are only a couple of points that jump out: -

Is your water anything other than bog standard Sydney tap water? If so what is it/have you added any salts
Your mash temp is 65-67oC, that is the mash temp not the strike water temperature isn't it.
A finer grind might help, but not 25%
And a personal bugbear - I would have another look at your thermometer. I don't really trust electronic or dial thermometers and would gave one good glass lab thermometer that I check it against, be aware that there are both total and partial immersion thermometers and that you could be 3oC out if you use the thermometer the wrong way.
Mark

Sorry started writing a response and went to serve a couple of customers and there have been lots of answers mostly similar to what I was saying.
M
 
Thanks all for the responses.

1. Mashin with a paint stirrer so confident the grist is getting a good mix and no dough balls/dry pockets.
2. I use brewmate. OG is taken with a hydrometer and is temp adjusted (and reconciled post boil). At an assume efficiency of 52%, I always hit my numbers (awesome).
3. I've feared that I wasn't getting all the goodness out of the bag, hence I've tried both voile and a CB bag. Rest assured I sqeeze the absolute beejesus out of it (twist plus a couple of saucepan lids) and leave it dripping until the start of the boil. No difference either way.
4. I'm only getting 17L post boil and with 2L trub loss because that's the volume I'm after (using brewmate). Re the grain/water ratio - I've just relied on the brewday settings in Brewmate. Should I change these? My absorption and boil off are about right.
5. I've tried an extend mash (to 75 mins not 90) didn't make much difference and I also found i was loosing a fit bit of temp over that time (ie up to 2 degrees).
6. Use bog standard Sydney tap. I've added a tsp of Gypsum to a IPA before but it made no difference.
7. 65-67 is mash temp (not strike).
8. Will recalibrate my thermometers. Pretty sure they are accurate, but my understanding was that provided that you were in that 65-67 band that most of the conversion happened in the firs hour. Pretty sure the thermoeter is at least accurate to +- 2.
9. Sparge probably would help, but there would seem to be more fundamental issues at play.

Sounds like the grain/water thing could be an issue. Maybe i'm mashing too thick. As I say, I just rely on the brewmate outputs to determine strike volume and I ultimately end up with the volume of wort i'm after (just using a shitload of grain).
 

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