First time BIAB - terrible efficiency. What did I do wrong?

[UKJay1971]

I ran a Dogfish Head 60 min IPA recipe taken from Beersmith. I won't go into all the recipe details however, equipment wise, I use a 70l pot with bag.

So, the recipe calls for 38 litres of water at the start , and I was aiming for a final 17 litres at the end of fermentation.

I follow the recipe - 60 min mash rest @ 68.9c (everything ran fine - had dropped about 1c over the hour which I thought was well within acceptable range). At the end, my wife squeezed as much wort from the bag as she could and I let it hang on a door handle to catch any residual run off which was all added back in.

I didn't take a pre-boil volume so I don't know how much we lost during that cycle.

Anyway, did a 90 minute boil, hopping from 60 mins down to zero as required.

I think this was my first mistake - in future I will add the bag back in for the hops so I can lift them out as one rather than leave them free in the boil.

Anyway, let the wort cool then started to transfer into the primary. I managed to transfer 13 litres of wort before it became unacceptably cloudy with sediment (and a ridiculous amount of wet hops - I had added one whirlfoc tablet at 15 mins).

I also missed my target gravity of 1.072 by 10 points (1.062) despite regular mixing of the grains during the resting stage, and a 7 min mash out to 75c at the end.

Ok - questions:

• What did I do wrong?
• Should I have bagged the hops up and squeezed them out?
• Need I have dumped so much cloudy wort at the end (must have been about 10 litres of it)?
• How did I miss my OG by so much?

I was expecting glitches as it was my first BIAB so any help would be greatly appreciated.

Thanks in advance

 

[PackerfaninSanDiego]

did you double mill your grains?

 

[UKJay1971]

No - they came pre-milled from my LHBS.

 

[PackerfaninSanDiego]

In BIAB, it is recommended to double mill your grains for better efficiency.

 

[RM-MN]

Hmm, three things come to mind. First is the quantity of water to start. You planed to start with 38 liters to end up with 17? That's a lot of water to boil off or leave behind in the pot. I would have started with more like 25 liters.
Second is the amount of wort and trub left behind in the pot. All that should go into the fermenter because it is mostly wort with enough proteins and hop material to make it look bad. It would have settled out into a very small amount at the end of the ferment and would have added no noticeable flavors.
Third is the crush of the grain. I understand why a LHBS would not crush too fine, the first person to have a stuck sparge would have come in complaining but with BIAB you can crush/grind your grains very fine since the bag forms the filter. That fine crush is where you would get the better efficiency. You can conpensate a bit for a coarse crush by mashing longer but there is a limit on how much it would help.

 

[UKJay1971]

Ok - thanks both of you. That helps. I'll try that next batch.

Sent from my Galaxy Nexus using Home Brew mobile app

 

[cheesehed007]

I'm about to do my first BIAB and I ordered a 3gal kit from NB. The grains came crushed, can I run them through a food processor or crush them with a rolling pin to get them finer? Thanks in advance.

 

[RM-MN]

I'm about to do my first BIAB and I ordered a 3gal kit from NB. The grains came crushed, can I run them through a food processor or crush them with a rolling pin to get them finer? Thanks in advance.

Yes to food processor, no to the rolling pin. The rolling pin won't accomplish much.

 

[cheesehed007]

Yes to food processor, no to the rolling pin. The rolling pin won't accomplish much.

Thanks!

 

[pricelessbrewing]

I.imagine the food processor will have a similar effect to blade grinding coffee beans. Irregular grinding leads to over extraction and under extraction on both ends which I imagine will translate to off tastes in beer and possible some strange tannin production. This is just from rough off the top of my head though, I don't know of any tests or comparisons of people doing this.

 

[Weezy]

I.imagine the food processor will have a similar effect to blade grinding coffee beans. Irregular grinding leads to over extraction and under extraction on both ends which I imagine will translate to off tastes in beer and possible some strange tannin production. This is just from rough off the top of my head though, I don't know of any tests or comparisons of people doing this.

I've never seen any documented evidence of this.

A finer grind creates smaller sized bits of barley that can more easily and more quickly be penetrated by the hot water to extract and convert the starches to sugar. With BIAB you're relying on the bag to act as the grain filter. This is unlike the traditional brewing methods where a coarser grind is necessary to permit the grain itself act as the filter. Advantage BIAB.

On the flip side, all those finer particles in the finer crush hold a lot more water (adhesion). This has the potential to leave a lot of sugar in the bag, adhering to the grain, especially with no sparge BIAB methods. This can lead to very poor efficiency. Traditional brew methods with batch or fly spares, don't have this problem. Advantage traditional brewing methods.

Tannin extraction is much, much, much more influenced by pH and temps than crush. Besides, take a close look at a single vs. Double crush sometime. The husks pop off and survive in large pieces through subsequent crushes.
...and none of this has to do with 'off tastes.'

 

[RM-MN]

I've never seen any documented evidence of this.

A finer grind creates smaller sized bits of barley that can more easily and more quickly be penetrated by the hot water to extract and convert the starches to sugar. With BIAB you're relying on the bag to act as the grain filter. This is unlike the traditional brewing methods where a coarser grind is necessary to permit the grain itself act as the filter. Advantage BIAB.

On the flip side, all those finer particles in the finer crush hold a lot more water (adhesion). This has the potential to leave a lot of sugar in the bag, adhering to the grain, especially with no sparge BIAB methods. This can lead to very poor efficiency. Traditional brew methods with batch or fly spares, don't have this problem. Advantage traditional brewing methods.

Tannin extraction is much, much, much more influenced by pH and temps than crush. Besides, take a close look at a single vs. Double crush sometime. The husks pop off and survive in large pieces through subsequent crushes.
...and none of this has to do with 'off tastes.'

You're right, that bag of finely milled grains holds a lot of wort and our efficiency is poor,

and then we squeeze the bag and almost all the wort come out and our efficiency approaches or exceeds 80%. Advantage BIAB again. Then some of us add a little water to that bag of mostly dry grains to absorb a bit more of the sugar, squeeze that out and efficiency goes up again. Advantage BIAB again.

 

[Weezy]

Most people squeeze the bag. Dumb not too. You're not going to squeeze tannins out of the grain like some people say. That doesn't mean there isn't a lot of sugar still stuck to the grains. You're then batch sparging, is what you're saying, to get what's left. Its a smart, easy process. Traditional BIAB is full volume, no sparge... low efficiency but nice, first running wort. I use a bag, double crush, but use more conventional brewing methods myself.

 

[pricelessbrewing]

Good to know. Ignore my previous post than, logical fallacy by analogy.
No such thing as over extraction of the grains.
Only issue with food processor is too much dust might not be caught in the bag.

 

[brewfreeordie]

I usually do 5-6 gallon batches and mash with about 6-7 gallons of water. I have a 4 gallon bucket that I drilled holes into the bottom that sits inside one of my 6 gallon bucket fermentors. Before I squeeze the grain bag I rinse the grains with a couple gallons of hot water (either from a cooler or straight from the HW tap) and add it to my kettle. The runoff usually has an OG around 1.020-1.030. It would save a step just to add a 1lb of grain or two but I can't see throwing it away.

 

[haeffnkr]

I usually do 5-6 gallon batches and mash with about 6-7 gallons of water. I have a 4 gallon bucket that I drilled holes into the bottom that sits inside one of my 6 gallon bucket fermentors. Before I squeeze the grain bag I rinse the grains with a couple gallons of hot water (either from a cooler or straight from the HW tap) and add it to my kettle. The runoff usually has an OG around 1.020-1.030. It would save a step just to add a 1lb of grain or two but I can't see throwing it away.

I do the above... it works great.

To add to this thought -
The keys to efficiency are repeatability...

You must do the same thing every time -
Get a grain mill so you can grind your own grain the same every time
Get 2 buckets - Drill holes in the bottom of one and put some bolts in it so it sits on top of the other one... you can use this to squeeze the bag and/or sparge a couple of extra gallons of watter with if you pot is not big enough
I use tastybrew calculator... it is SPOT on and will till you what your effeciency is/was so you use it next time

Also - make sure you hit your water volumes you expect... it will make a much bigger impact on your efficiency than mashing will.

good luck
Kevin

 

[Milan37]

Traditional BIAB is full volume, no sparge... low efficiency but nice, first running wort. .

But traditional BIAB (full volume, no sparge) doesn't result in low efficiency.