I am always tweaking things in the brewery. Motivation for these changes vary, but usually start with a curiousity and snowball from there. This year’s updates have been related to an idea I’ve been sharing for recirculating mash systems. These types of breweries require recirculation that is quick enough to keep wort well mixed such that temperature readings are representative (minimal lag and stratification), heat exchange is effective (ideally somewhat turbulent flow), and mash solids (coagulated proteins, lipids, various grain material) suitably suspended to prevent scorching and other issues. At the same time, the draw/return rate from the mash lauter tun must be low enough as to not cause grain bed compaction, vectoring, etc.
My idea is not unique, but I haven’t seen it used by another homebrewer anyways. It involves a high flow rate “loop” in a breweries plumbing, which should prevent the formation of excess pressure across the grain bed (i.e. can work as a wort grant, essentially), and also allows higher flow rates in a HERMS coil or RIMS heater without requiring a high draw/return from the mash lauter tun. I don’t know exactly what to call this modified design. RIMS+loop and HERMS+loop?
Some brewers, myself included, have been reducing the wattage of their inline heater during the mash recirculation process. This remains as a good, common-sense idea, though I expect that with this kind of system you may not find that is necessary. I personally will be experimenting with gradually lifting the limiter I apply during mash recirculation.
Everything is perhaps best explained diagrammatically. Check out Figures 1 through 3 for plumbing and flow paths during mash recirculation, lautering, and whirlpool. The descriptions contain lots of extra details.
This will surely require some optimization on my part. I expect that it is not suitable for most homebrewer pumps (e.g. smaller chugger or march pumps), though I could be wrong (I use a 1/2 hp sanitary centrifugal pump).
In terms of “dials to tweak” that I have with my brewery using this design, I now have a couple full port quick clean ball valves for my mash lauter tun and boil kettle return ports which should offer reasonable flow rate control. I also have VFD pump control which can control the flow rate and pressure of the pump-heater loop. There is also a small amount of flow rate control possible with the butterfly valves throughout my brewery – but not much!
I have some concern over the generation of excessive wort shear. I have not researched this sufficiently, but my understanding is that it can be damaging to wort quality in ways. Certainly it can disrupt coagulations of proteins and lipids, possibly allowing these materials to be carried further through the brewing process than might be ideal. Perhaps having impacts to beer stability or clarity. Whether proteins are actually degraded somehow seems unlikely to me with the forces that I would be generating… but not an expert here (yet).
I would very much like to incorporate one or two sight glasses to my revised plumbing. These are very useful in monitoring the brewing process (e.g. mash running clarity, flow rate), but I have not found a great placement for them yet.
I also have to make a new brew stand or modify my existing one to work with my new plumbing. Pump placement, spacing, support locations are all slightly different. I am leaning towards making a completely new stand from lumber in case I end up wanting to go back or something. The materials are very cheap and already on hand, so no issues there.