(yet another) TETB sparging gizmo

[The-Engineer-That-Brews]

Y'all know the drill: I love an excuse to build a new gadget under the thin disguise of improving my brewing
So here's the latest - a new, improved (probably) sparging gizmo.

I recirculate during the mash using a pump; and at the moment I distribute the wort over the top of the grain with a spiral of 3/8" tubing with holes drilled in it.
It works OK but I've always been a bit dubious as to whether 90% of the wort comes out in the first few holes, leading to a rather uneven flow.

So I've been thinking for a while about a small DIY version of the sort of sparge arm you might see in a full-sized setup like this:

However because the length of my arm is going to be a lot less, I couldn't see a way to get the pressure high enough to make it rotate under its own steam (like a lawn sprayer); and in any case I couldn't see an easy way to make a fluid-tight rotating joint.

Then I thought actually, the arm doesn't need to rotate continuously - it can just swing to and fro over a 180º arc and the effect will be the same.

So here's my solution: total cost £12 for a cheap servo motor, a bit of scrap aluminium sheet to mount it, about £5 worth of brass rods, a couple of JG fittings and some silicone tubing:

The servo is driven by a weeny little embedded controller (about another £4's worth) that runs some very simple code to rotate it continuously to and fro over a 180º arc.
The servo is mounted on the lid of the mash tun and coupled to a 6mm brass rod that runs down into the bucket through a bulkhead fitting.
Then at the other end of the rod there's another rod drilled that supports the sparge arms (more tubing with holes drilled in).
The wort is fed down through the silicone tubing, which is flexible enough to take up the +/- 90º rotation.

Et voila ... now all I need to do is test it with some real beer !

 

[The Biochemist]

Impressive! Can’t wait to see it in action hear if it improves your efficiency!

 

[The-Engineer-That-Brews]

Heh - thanks: it's not so much that I need more efficiency (the beer is all too often embarrassingly strong), as that I would like the efficiency to be more consistent. I'm paying a lot of attention to temperature control and enzyme denaturing rates (something I should probably talk to you about!!)

 

[The Biochemist]

Consistency is the dream, although I suppose the nice thing about fly sparging is you just collect till you hit your pre-boil SG and job done! :)

Are you doing single temperature infusion of step mashing?

 

[The-Engineer-That-Brews]

Consistency is the dream, although I suppose the nice thing about fly sparging is you just collect till you hit your pre-boil SG and job done! :)

Are you doing single temperature infusion of step mashing?

Step mash: I recirculate throughout the boil, whilst managing the temperature of the re-criculated wort with a heat-exchanger ('HERMS').
I've recently realised though that while I'm "overdriving" the HERMS temp to increase the grain bed up to the next rest, I'm likely at risk of denaturing the enzymes as they are passing through the heat exchanger. I've got a plan for that though

 

[pilgrimhudd]

So....... you've invented a water sprinkler that fires downwards?

 

[The-Engineer-That-Brews]

So....... you've invented a water sprinkler that fires downwards?

 

[The-Engineer-That-Brews]

To be fair, I think @Buffers brewery still wins the prize for sparging machines :-)

 

[Redgrave_3]

I wonder if there’s any merit in drawing off an amount of wort from the mash and adding back hotter water, kind of like the way you’d raise the temp in a decoction?

You could raise the temperature and decrease the proportion of sugar in the wort (so it could accommodate/extract more).

In-mash-pre-sparging IMPS.

 

[Buffers brewery]

Love a reciprocating sparge machine. We need more reciprocating sparge machines.
Regarding increasing mash temperature, my HERMS tank is a re-purposed 10 litre swing lid waste bin so warms up slowly. I set the temperature to mash temperature plus 2C (for loses down pipes and RSM) and it takes about 15-20 minutes to reach target temperature.

 

[Hanglow]

I love a gadget, but i love no sparge brewing more

 

[The-Engineer-That-Brews]

I love a gadget, but i love no sparge brewing more

So a full volume mash, I guess...
How do you rinse the sugars off the outside of the grains?

 

[The Biochemist]

So a full volume mash, I guess...
How do you rinse the sugars off the outside of the grains?

No need, you just accept the lower efficiency and add extra grain!

 

[The Biochemist]

Love a reciprocating sparge machine. We need more reciprocating sparge machines.
Regarding increasing mash temperature, my HERMS tank is a re-purposed 10 litre swing lid waste bin so warms up slowly. I set the temperature to mash temperature plus 2C (for loses down pipes and RSM) and it takes about 15-20 minutes to reach target temperature.

This. Slow and steady is generally the way to go with HERMS. Although saying that, mash enzymes can tolerate surprisingly high temperatures providing the exposure time is short enough.

 

[The-Engineer-That-Brews]

This. Slow and steady is generally the way to go with HERMS. Although saying that, mash enzymes can tolerate surprisingly high temperatures providing the exposure time is short enough.

When I started using the HERMS I did some work to monitor the different process temperatures during the mash steps (see this thread: Monitoring mash temps - results).
The relevant bit is probably this plot. The red line shows the temp of the water on the 'hot' side of the heat exchanger and the other lines show the temp at various depths of the grain bed.

As you can see, what I was doing was 'overdriving' the temp of the recirculating wort, in order to get the grain to the rest temperatures as fast as possible.
I'm wondering whether I need to rethink this however, because this approach exposes enzymes dissolved in the wort to significantly higher than the target temp while travelling through the heat exchanger (probably about 30sec - it's a 10m tube).
One of the key questions is whether the enzymes are predominantly in solution in the wort, or largely acting within the mash grains. Any insight into that would be greatly appreciated.

 

[peebee]

... One of the key questions is whether the enzymes are predominantly in solution in the wort, or largely acting within the mash grains. Any insight into that would be greatly appreciated.

From my work with "cold extraction ...

The enzymes are exceedingly soluble in water. So, the answer based on what I've been doing: "predominantly in solution in the wort". (How long it takes for the enzymes to leach out of the grains ... well, that's another question).


[EDIT: I should better quantify that: Apparently (!) you can reuse the malt grains subject to cold extraction (a low-alcohol brewing technique). The "extraction" only removes the soluble sugars, some starch (as an emulsion) and ... all the enzymes. So, reusing the grain requires it to be treated as an un-malted adjunct.]

 

[Hanglow]

No need, you just accept the lower efficiency and add extra grain!

Yes, this. I still get good efficiency up to about 1.052 or thereabouts, which covers 90% of all the beer i make.

 

[The Biochemist]

When I started using the HERMS I did some work to monitor the different process temperatures during the mash steps (see this thread: Monitoring mash temps - results).
The relevant bit is probably this plot. The red line shows the temp of the water on the 'hot' side of the heat exchanger and the other lines show the temp at various depths of the grain bed.
View attachment 65788
As you can see, what I was doing was 'overdriving' the temp of the recirculating wort, in order to get the grain to the rest temperatures as fast as possible.
I'm wondering whether I need to rethink this however, because this approach exposes enzymes dissolved in the wort to significantly higher than the target temp while travelling through the heat exchanger (probably about 30sec - it's a 10m tube).
One of the key questions is whether the enzymes are predominantly in solution in the wort, or largely acting within the mash grains. Any insight into that would be greatly appreciated.

Love a good chart!

As Peebee says, the majority of your enzyme will be in the liquid phase; the pertinent question is how much of your total mash is exposed to these temperatures, which of course relates to your flow rate.

If it’s just a small proportion, fine. If it’s all of it, or even all of it multiple times, then you may have a problem.

Saying that, the easiest answer will come from a taste test of the final beer: if it’s overly sweet then you’re prematurely denaturing your beta amylase, it not then all good!

 

[The-Engineer-That-Brews]

First outing for the new sparge arm yesterday - all good.

 

[The Baron]

The "Spargemaster" forum member formerly known as "The Engineer that Brews"