Hey guys,
I recently (3 batches ago) upgraded to a new system and have been having a few variable issues with recirculation, efficiency, and other techniques I was hoping the collective expertise of the internet could help me troubleshoot. Before we get started, this is my system:
With that out of the way, here are the issues that have popped up:
In my most recent batch (designed to be ~11G of a ~8% DIPA, 35# of grain, 39oz of hops), I had planned to reserve ~3.5G of water for a pour-over sparge after pulling the basket out of my mash as I couldn't run a full volume mash due to the amount of grain (I top out around 28-29# for full-volume of heavily hopped beer when shooting for 11G post-boil wort).
Heated my strike water (~14.5 gallons), mashed in, hit my desired temp, broke up dough balls, let things settle down a bit, and turned on the pump (as low as possible) trying to get some recirculation going. I wasn't able to get any sort of recirculation going and resorted to stirring occasionally to try and ensure even conversion/efficient conversion. 15min in I checked my mash pH and it came in a touch low (5.25 measured against 5.3 predicted), but within a reasonable realm. Mashed for 1hr, lifted the basket above the kettle to drain, started heating the collected wort and poured over the 3.5g of reserved water over the top of the grain, letting it drain into the kettle. I checked both first runnings gravity and pre-boil gravity, both of which were low (~1.058 preboil compared to an expected ~1.070). First runnings, sparge, and pre-boil volumes were almost exactly as predicted.
I went through, boiled/added hops/cooled/transfered to fermenters/pitched yeast/etc and everything is happily fermenting away now. OG was low ~1.065 against 1.080 predicted, so this beer will come in much lower in ABV. My main questions/where I hope I can get some help is: Why did my efficiency take such a hit compared to previous batches? And how can I improve my technique to take full advantage of the recirculation ability/etc?. I had previously done 2 other batches on this system, both full volume mashes and hit all of my numbers (temp, volume, pH, gravities) on the nose. I maxed out the system with 28.5# of grain and obtained a comparable OG to using 35# of grain, which is disappointing to say the least - All full-volume batches on this system (And previous systems) have been 70%+ efficient with numbers almost exactly as predicted.
The potential issue points that I've identified from reading/etc are:
I apologize that this has turned into more me throwing ideas up and seeing what sticks. Trying to summarize/streamline:
I am hoping to get some advice about how to maintain efficiency in a single vessel BIAB system when attempting to obtain high starting gravities and exceeding my vessel's capacity for a full-volume mash.
Additionally, I am hoping to get some advice on how to improve my recirculation technique as I eventually want to incorporate an outboard RIMS tube (as a precursor to eBIAB) which would rely on being able to efficiently/consistently move wort over the heating element and draw wort from the mash tun/kettle evenly.
Thanks for any/all help! I am currently at work, but if it would be helpful, I can provide more specific recipe information/session information or equipment information when I get home tonight.
I recently (3 batches ago) upgraded to a new system and have been having a few variable issues with recirculation, efficiency, and other techniques I was hoping the collective expertise of the internet could help me troubleshoot. Before we get started, this is my system:
- 20g kettle, 4x 1.5" TC fittings (2 capped, 1 for a thermometer, one with a dip tube/butterfly valve).
- 300 micron stainless solid-sided mash basket (sits ~3" off the bottom)
- Center inlet chugger pump + soldered 1.5" TC fittings on inlet/outlet
- Detachable whirlpool arm used for mash recirculation and post-boil whirlpool/hop-stand (externally mounted, ~15" long so comes in a few inches above the bottom of the basket (when inserted) or kettle.
- 25' Stainless counterflow chiller
- 1/2" ID silicone tubing, 1.5" butterfly valves, 1.5" TC fittings connecting everything up
With that out of the way, here are the issues that have popped up:
In my most recent batch (designed to be ~11G of a ~8% DIPA, 35# of grain, 39oz of hops), I had planned to reserve ~3.5G of water for a pour-over sparge after pulling the basket out of my mash as I couldn't run a full volume mash due to the amount of grain (I top out around 28-29# for full-volume of heavily hopped beer when shooting for 11G post-boil wort).
Heated my strike water (~14.5 gallons), mashed in, hit my desired temp, broke up dough balls, let things settle down a bit, and turned on the pump (as low as possible) trying to get some recirculation going. I wasn't able to get any sort of recirculation going and resorted to stirring occasionally to try and ensure even conversion/efficient conversion. 15min in I checked my mash pH and it came in a touch low (5.25 measured against 5.3 predicted), but within a reasonable realm. Mashed for 1hr, lifted the basket above the kettle to drain, started heating the collected wort and poured over the 3.5g of reserved water over the top of the grain, letting it drain into the kettle. I checked both first runnings gravity and pre-boil gravity, both of which were low (~1.058 preboil compared to an expected ~1.070). First runnings, sparge, and pre-boil volumes were almost exactly as predicted.
I went through, boiled/added hops/cooled/transfered to fermenters/pitched yeast/etc and everything is happily fermenting away now. OG was low ~1.065 against 1.080 predicted, so this beer will come in much lower in ABV. My main questions/where I hope I can get some help is: Why did my efficiency take such a hit compared to previous batches? And how can I improve my technique to take full advantage of the recirculation ability/etc?. I had previously done 2 other batches on this system, both full volume mashes and hit all of my numbers (temp, volume, pH, gravities) on the nose. I maxed out the system with 28.5# of grain and obtained a comparable OG to using 35# of grain, which is disappointing to say the least - All full-volume batches on this system (And previous systems) have been 70%+ efficient with numbers almost exactly as predicted.
The potential issue points that I've identified from reading/etc are:
- Dough balls/dry spots not efficiently converting. Potential solution: efficient recirculation, more careful stirring/breaking up of dry spots/dough-balls.
- Inefficient recirculation - I wasn't able to get any real movement going. My initial thought is that this is due to the return from my whirlpool being within the grain bed rather than returning on top of it. Potential solution: replace stainless WP arm with silicone hose that sits on top of grain bed (or locline or something similar). Another potential issue: too fine crush - from what I have read, crushing too finely can inhibit your ability to efficiently recirculate. Some places I've seen suggest backing the crush size off pretty significantly and then making up efficiency due to the recirculation.
- Coarse crush - Most places discussing efficiency with BIAB suggest crushing as fine as possible. This conflicts with the information I've seen about improving recirculation and I would appreciate any insight into how to balance these two competing interests.
I apologize that this has turned into more me throwing ideas up and seeing what sticks. Trying to summarize/streamline:
I am hoping to get some advice about how to maintain efficiency in a single vessel BIAB system when attempting to obtain high starting gravities and exceeding my vessel's capacity for a full-volume mash.
Additionally, I am hoping to get some advice on how to improve my recirculation technique as I eventually want to incorporate an outboard RIMS tube (as a precursor to eBIAB) which would rely on being able to efficiently/consistently move wort over the heating element and draw wort from the mash tun/kettle evenly.
Thanks for any/all help! I am currently at work, but if it would be helpful, I can provide more specific recipe information/session information or equipment information when I get home tonight.