Rubbish Biab efficiency!

[Redron]

Following on from MyQul's brewday thread and ongoing discussions re grain crush and efficiency...
Today I brewed a Tim Taylor Boltmaker clone with a view to improving my relatively poor efficiency from past brews using the true Biab method, i.e. Full 33L of strike water, squeeze the life out of the grain bag, and no sparge.

The recipe called for 3670 MO, 31 black malt and 195 crystal malt. I upped the MO to 4250 with a view to hitting a reasonable OG and to compensate for any 'poor'efficiency.

This time I used 22L strike water, mashed for 90 mins and then dunk sparged in a spare fv with a further 12 litres at 80degs for a good 10 minutes whilst the rest of the wort was on it's way to boil. I also stirred once during the mash and also stirred a couple of times during the dunk sparge.

After a 90 min boil I was left with 20L in the fv with an OG of 1040. According to the forum brewhouse efficiency calculator I make that 56.5% efficiency !

Disappointed ? I'll say. I can normally get somewhere between 60 and 68%.
This was an attempt to improve my efficiency, not make it worse !

Where am I going wrong ?

 

[TartanSpecial]

What is your water profile like..is it hard water that need the excess alkalinity stripped out of it??? Am assuming on the isle of Skye you should have soft water but I might be wrong....

 

[nigelnorris]

Following on from MyQul's brewday thread and ongoing discussions re grain crush and efficiency...
Today I brewed a Tim Taylor Boltmaker clone with a view to improving my relatively poor efficiency from past brews using the true Biab method, i.e. Full 33L of strike water, squeeze the life out of the grain bag, and no sparge.

The recipe called for 3670 MO, 31 black malt and 195 crystal malt. I upped the MO to 4250 with a view to hitting a reasonable OG and to compensate for any 'poor'efficiency.

This time I used 22L strike water, mashed for 90 mins and then dunk sparged in a spare fv with a further 12 litres at 80degs for a good 10 minutes whilst the rest of the wort was on it's way to boil. I also stirred once during the mash and also stirred a couple of times during the dunk sparge.

After a 90 min boil I was left with 20L in the fv with an OG of 1040. According to the forum brewhouse efficiency calculator I make that 56.5% efficiency !

Disappointed ? I'll say. I can normally get somewhere between 60 and 68%.

Where am I going wrong ?

I've used near enough that same grain bill a couple of times recently biab style and get close to 70% each time.

I use nearer 30L to mash in then bring that back up to 30L with a dunk sparge [so another 4 or 5]. In other words a compromise between your two efforts. I end up with the same 20L that you're aiming for.

Could it be that 12L is too much sparge, maybe that's coming out thin so all you are doing with that dunk is watering the mash down?

 

[Bodleigh Head]

You could look into your grind ... has the mill slackened off ?
Old malt ? I have had diminishing returns with old malt.
Did you check the pH of your mash ... hard water doesn't help.
I manage to get 70 to 75% efficiency with a picnic cooler and batch sparging ... if that is any consolation ... 68% sounds good for BIAB ... but I have never used the technique.

 

[JFB]

I suffered from bad efficiency for a few brews on the trot once which ended after the bag of crushed marris otter ran out. Have all your recent brews come from the same batch? Its probably not the cause but could be???

 

[Leon103]

Where do you get your grain. Crushed or whole?

I use the Irish malt from geterbrewed and biab m, getting 78-80%. I tend to mash with 3l per kg of grain. I then squeeze the bag, pour about 4l of water 80c through the grain, I use a funnel. I again squeeze.

I then let the bag soak in 10l of water for 10 minutes. Squeeze and add the water to the boiler.

Forgot I also do a mash out

 

[dan125]

I normally get 65-70% efficiency with BIAB and a 5L sort of sparge to rinse the grains.
I'd stick with your original method - as long a you have a pretty good idea what your efficiency will be for a given brew, it doesn't matter if its a bit low. It'll just cost you a few pence more in grains

 

[Covrich]

So as I understand you normally do true BIAB (no sparge) but this time you did a mash biab and a sparge??

What a few people above might not be aware of is you have had a problem for a while I think and you typically do the true BIAB without a sparge stage, Regardless I still find true BIAB (no sparge) I get around 70-75% average (78% on the last one) so There is no reason to suggest you cannot either with this method why do I say this? I can relate I have had efficiency problems when I started even with sparging and have experimented with methods which seem to deliver me consistently over 70%.

It seems both methods are causing problems..

I think like others suggested above

1) check your grain fineness (and freshness) This made an enourmous difference to me when I started brewing even with dunk sparging
2) Possibly check themometer??? could be something slightly out causing issues
3) How much time do you spend doughing in.. try and spend a good while.. do it slowly add a little at a time and really mix it in
4) Mid mash stirs do you get right to the bottom and really kick up and stir the rested grain at the bottom..?
5) try mashing out, if doing true BIAB it is easy raise the temp with teh grain in there or raise the bag out while it heats up a little and return it stirring and then rest
6) Tartan also mentioned a really good one, maybe the water??

 

[Redron]

Some interesting input there, thank you.
Whilst we live in a limestone area our water comes from an area which isn't and appears to be pretty soft, though I haven't tested it.
I'd never considered the freshness of the grain. I have been buying it from the same place since I started on Biab, in 25kg sacks and crushed at source. I think it's time to buy a grain mill and buy my grain whole...
Covrich, I like your observation re stirring thoroughly during the mash, I think to date I haven't been, just a quick stir and perhaps not getting right to the bottom.
Also the mash out, I have done in the past though only for a short time as I was afraid of burning the bottom. My thermometer is a Thermapen, not cheap so I would be disappointed if it was inaccurate!
I may try a different grain supplier firstly, I believe Malt Miller will crush your grain to your requirements, though they are a fair bit dearer than my current supplier (£23 per 25kg).
Once again, thanks for the input.

 

[TartanSpecial]

I think it's time to buy a grain mill and buy my grain whole...

I think thats a good way to go (plus longer mashing in..I spend 5-10 minutes making sure there no dough balls ). My efficiencies went up alomost 10% when I started grinding my own grain on brewday. Also the whole grain stores for ages without any noticeabe decrease in conversion ability. Malt Miller is a good supplier...

 

[Covrich]

Yeah I think you are going to get a unanimous vote for milling your own grain here. Biab especially, and full volume even more so benefits from it.

 

[dan125]

My efficiencies went up alomost 10% when I started grinding my own grain on brewday. Also the whole grain stores for ages without any noticeabe decrease in conversion ability. Malt Miller is a good supplier...

Do you have to mill the grain outdoors?
I was going to get a mill a while ago but read a few of reports about it giving off a lot of dust.

 

[Covrich]

I have milled in my kitchen loads of times but have had to vac up after

 

[MyQul]

I do what Cov does and vac up after. I dont get loads of dust in the air (or any that ive noticed in fact perhaps that only happens when using a drill?) but even with a long bread tin to catch the grain some still ends up on the table or on the floor

 

[MyQul]

I may try a different grain supplier firstly, I believe Malt Miller will crush your grain to your requirements, though they are a fair bit dearer than my current supplier (�£23 per 25kg).
Once again, thanks for the input.

I'm buying my first 25kg sack of grain from either GEB or HBC as they only charge £19 for a 25kg sack of their irish malts and if I can get an increase in efficiency by milling my grain really fine then it works out even cheaper as I will need a bit less grain per brew

 

[wfr42]

From my first use of my Xmas mill purchase
2kg of specialty grain in about 10-15mins

Not a bad mess and as always I try and leave space I've brewed in cleaner than I found it.

 

[dan125]

I might have another look at mills then, as even will pre-crushed grain I usually manage to get some grains/dust around the kitchen.

The Malt Miller will indeed crush grains fine if you ask them to, and I noticed a few % increase in efficiency with the finer crush.

 

[Redron]

I'm buying my first 25kg sack of grain from either GEB or HBC as they only charge �£19 for a 25kg sack of their irish malts and if I can get an increase in efficiency by milling my grain really fine then it works out even cheaper as I will need a bit less grain per brew

I have had quotes for delivery from GEB and HBC, attracted by their very good grain prices.
One was £19 delivery to Skye, the other quoted me 60 Euro.....:-o
My own fault I guess for living in the back end of nowhere !

So my mission now is to find a good whole grain supplier who will deliver to Skye at reasonable cost (currently paying 14 quid for up to 30kg).
Answers on a postcard please....

 

[chub1]

Have done a few BIAB brews and all but the last two have been a fair way under the expected OG.Have varied between full volume mashes and sparging. My last two brews i have dunk sparged,drained the grains into the larger pot and then sparged with the dunked liquid/wort and given the bag a light squeeze,both times i have either hit the OG or just above it.Dunk sparging now for me:thumb:

 

[Brew_DD2]

I've always achieved better efficiency with a dunk sparge.

Any ideas on where to get a good, cheap miller? Or indeed if there is an easy diy option?