Using a Grant in Home Brewing

[Dougy2]

I have developed (attached) a method to use a Grant in my home brewing setup. It applies all the principles outlined in Dave Millers "Brew Like a Pro" and in the subsequent article he published on his website (as Appendix). A Grant enables very fine filtering of wort during vorlauf and in this version enables near automated Sparging. It is a fairly simple addition to a HERMS rig, sets up mash filtering by controlling precise wort levels in the mash tun, uses continuous controlled wort flow and helps avoid stuck mash issues. I have found it works exceptionally well and provides for consistency in small brew batches by filtering out fine protein particles from the pre-boil wort.

 

[Sidney Harbour-Bridge]

Wow, that's quite a paper, I've read Dave Millers book and thought the grant looked like an opportunity for things to go wrong.

For instance my dog likes to help me brew, hairs and drool could easily get into the grant and it could be knocked over.

I like to minimize mash oxygen exposure, I can't see the grant helping with that.

It doesn't actually clarify the wort, it lets you see how clear it is, a section of clear pipe as used in level gauges would allow you to see clarity with less risk, if you wanted to see a thicker section, a sight glass in your HERMS line would allow you to monitor as the mash progresses. I think I might try adding one to my RIMS stick to see how the wort looks.

 

[Dougy2]

I think all your concerns are covered. The devil is in the detail.

I hope I have advanced on Daves level switching pump approach to a Grant. The usual for bigger brewery is to run the pump below the Grant on a VSD to maintain a set level in the Grant itself. Have a look at pages 153 – 157 of “Brew Like a Pro”.

Your dog is safe from even cocking a leg to the Grant – in my system it is placed overhead above the Mash tun by some distance to provide a head of wort to the float valve level control in the mash tun. In a RIMS/HERMS system a recirculation loop a pump puts wort through the Heater/Hex and returns it to the mash tun with maybe some flow control (a valve). In my system I have added a flow meter (maybe it’s not required) and up above the mash tun a Grant, before the wort flows down to the float valve level control. As the mash tun level is lowered (you have control of this) the level in the Grant will rise (I have added an indicator on the side) remembering the system volume is constant. The beauty is that the flow and the levels settle to become constant so not disturbing the bed filtering by on/off flows. My Grant is made from an asparagus cooker (it has a lid).

The recirculation loop is maintained for temperature control at higher flow rate, a lower rate for Vorlauf and at a controlled rate for sparging after the loop is diverted to the brew kettle.

I was careful to reduce oxygen exposure to the hot wort. The only increase in the system is the surface area of the wort in the Grant – this can be reduced with floating plastic balls if to want. There is no spraying or dribbling of wort through air as in commercial systems. The pinch type float valve modification is designed to avoid splashing wort into the mash tun, which is one reason I elected to not use a Blichmann float level valve.

There can be many functions of a Grant. Some clarification happens when particles are left in the bottom of a typical under mash tun unit. Mine, and Dave Millers approach is to use it to reduce the wort volume in the mash tun so the bed compacts enough to form a very effective filter (see the appendix to the article). Filtering out proteins is important to wort consistency. Some proteins are very fine – crushed grain has some flour in it – and some are even dissolved. I can speculate that at least some of the dissolved ones will agglomerate or flocculate when near others in the filter. A finer filter will enable this process. It is fair to say that the fine filter in this system is better than the filtering achieved by RIMS/HERMS recirculation alone.

In my system the flow meter is a variable area type – you get to see the fluid in it – so it acts as a sight glass. It happens to have a control valve fitted under it for flow control as well. Daves efforts give relatively precise flow rates for Vorlauf and Sparging (see P153-157 and the appendix to my article) so its handy to have the flow meter. I am about to add the bypass for the flow meter because it can filter enough particles out to block up and the bypass will let these get caught in the mash filter during initial flow.

You absolutely can add a Grant to your RIMS system, think about placing it above your mash tun rather than under it.