Mash thickness with recirculation

[verysupple]

Hi all.

I’m planning a new recirculating 1V rig similar to Qldkev’s and others. I.e. two pots, one inside the other, where the inner one has a false bottom and acts as a malt basket / pipe. The liquid recirculates to the top of the grain bed (not the bottom like a Braumeister).

I’m just wondering what sort of liquor-to-grist ratios people use with rigs like this, or any RIMS. I’d like to just use the full volume needed to get my desired pre-boil volume, but my calculations indicate that this would give a fluidisation in the malt pipe of ~4 L/kg for an average strength beer. Is that too high given you want to “float” the mash to get good liquid flow through it, or does it not matter that much?

Thanks for any advice.

 

[TheWiggman]

Definitely not a 1V-specific issue, and applicable to any RIMS/HERMS system (i.e. anything that recirculates). I use 3l/kg as a rule (I fly sparge) and sparging typically is about 30% more than my mash-in water. Say 15l in the mash tun, 20l for sparge.
I used to recirc with 2.5l/kg but went up to 3 mainly because it meant less sparging (I was also trying to address stuck sparges but this turned out to be another matter).
I think provided your return flow allows some form of circulation around the bed to avoid channelling, then most bases are covered. What's the benefit of a floating mash?

 

[verysupple]

Yep, as the title suggests, it's definitely applicable to any recirculating system. I just wanted to set my particular context.

As for the floating mash, I'm not sure there is a benefit. I just remeber reading in another thread (possibly about brau clones) about ideal fluidisation and had a feeling that if there was too much liquid the mash might settle down and compact under the extra pressure, resulting in a stuck mash. I could be completely wrong on that one, that's why I asked.

I should also explain why I kind of want to start with the full volume of water. If I aim for 3 L/kg in the malt pipe then I would be sparging with <10 L to get the pre-boil volume. This is due to the space between the two pots leading to a large strike volume. If possible I'd like to save the effort and just not bother with a sparge.

 

[TheWiggman]

Yep wasn't trying to suggest you meant it was a 1V only case, I was agreeing with you. From my limited research there is little to no issue with a thin mash, but you can run into trouble with a thick mash. Pre-BIAB the main reason for lautering was the absence of a bag altogether. There are now many Braumiester and BIAB brewers who don't sparge, so from that observation alone I think that's all the evidence you need to support going full-volume mash. The only issue would be not being able to squeeze the grains, so you would lose some efficiency over a well managed BIAB dare I say.
I don't find compaction any more or less of an issue with a different mash thickness. All that really changes is the volume of liquid on top. More water won't apply additional pressure on a false bottom, the pump flow rate and mill setting would have the largest impact.

 

[verysupple]

Cheers Wiggman, good info.

Good point about BIAB. If you can recirc. in that situation where the fluidisation is even higher, then of course there shouldn't be a problem in my situation. Dunno why that didn't occur to me before. I'm not too fussed about efficiency as the new rig will be able to handle quite large grain bills so if needed I'll just use a little more grain than before.

 

[QldKev]

In my 1V I strike with 23L. I strike at that, then add water until I'm happy with the level it is recirculating at. The less grain in the batch the more water needed. After I've lifted the basket to drain, I then just "bucket sparge" until I get my desired 32L pre-boil volume. My "bucket sparge" is just fill a handi-pal with cold water from my water filter. Then I just tip that cold filtered water into the grain until I think the correct amount of vol should drain, if anything under estimate it. Sometimes I may need to sparge a couple more liters of water to get up to the exact vols. I'm doing a 28L batch, so you will need to review the numbers to suit your batch/pot sizes.

 

[verysupple]

Thanks, Qldkev.

The less grain in the batch the more water needed.

I'm not sure I understand this bit. Do you need more water when using less grain because you can have the flow rate higher and still maintain a good liquid height difference between the two pots?

 

[nala]

I made a return pipe using a "T" piece an elbow and a tap...see attached picture.
The long pipe goes to the bottom of your outer vessel and the short pipe with the tap into your mash vessel, by adjusting the tap you can keep your pump on full flow, the returning wort either goes into your mash vessel or into the outer vessel.
I always use a mash liquor volume as a standard 20 litres, you can mash approx 5.5 kilos using the 19 litre pot.

 

[verysupple]

Neat design, nala. I'm also planning to have a lower inlet for the outer pot to be able to keep the pump going flat out and also get good circulation in the outer pot. Here's a pic of my design so far (note the inner pot isn't in this pic).

 

[QldKev]

Thanks, Qldkev.



I'm not sure I understand this bit. Do you need more water when using less grain because you can have the flow rate higher and still maintain a good liquid height difference between the two pots?

Not flow rate, I run the pump on full regardless of the grain. It's just less grain take up less space, so I use more water to get the water height back up.

 

[micbrew]

what size batches are you planning on ? 20 / 40 batches bigger

work back from there ! this will dictate ..pot sizes etc

its a little daunting .. but worth getting it right from the get go ...


good luck

 

[Dazzbrew]

HI

I’m just wondering what sort of liquor-to-grist ratios people use with rigs like this, or any RIMS. I’d like to just use the full volume needed to get my desired pre-boil volume,

Thanks for any advice.

I am also planning a recirculating 1V also inspired by QLDKev but in my case at the moment I plan to continue to use the bag and full volume of liquor. If you use full volume you may just have to have your inner pot sitting higher in the outer pot.

as far as full volume goes the 'Brew Easy' system also uses full volume, just with 2 vessel's.

 

[verysupple]

what size batches are you planning on ? 20 / 40 batches bigger

work back from there ! this will dictate ..pot sizes etc

its a little daunting .. but worth getting it right from the get go ...


good luck

Way ahead of you there. Hardware is pretty much all planned. I'm aiming for 25 L into the FV (less if I'll need more head space like when doing a weissbier). The pots I'm planning on getting are 60 L outer, 40 L inner. These sizes leave plenty of leeway and will allow quite large grain bills for bigger beers. The only question I really had was about full volume mashing vs sparging.

 

[verysupple]

I am also planning a recirculating 1V also inspired by QLDKev but in my case at the moment I plan to continue to use the bag and full volume of liquor. If you use full volume you may just have to have your inner pot sitting higher in the outer pot.

as far as full volume goes the 'Brew Easy' system also uses full volume, just with 2 vessel's.

The BrewEasy looks sweet...but a bit out of my price range. It actually inspired my design. Then when I started researching I came across QldKev's thread about his 1V and found quite a few people have built or are building similar systems. It turns out my great new idea for a compact, simple brewing system that's cheaper than a Braumeister wasn't actually anything new.