Grain Mill 2.0

As I’ve mentioned in previous posts, we moved to Florida and I had to leave certain things behind; this includes the cart/stand for my grain mill. I took off the important parts like the bare bones mill, the motor, the sheave, etc. with the plan to rebuild it in Florida. After finishing rebuilding the brew stand, I turned my attention to the grain mill and decided I wanted to change things up. Instead of the guillotine-like sheave, I decided I wanted to use a gear motor in more of a direct drive orientation. More details below.

Gear Motor

I was planning on buying a cheap gear motor on Amazon that included a speed controller. Currently these models sell for around $100-$130 on Amazon under various brand names and all appear to be made in China. Final drive RPM and torque vary quite a bit but I found one that seemed to fit the bill. The only problem was none of these motors had many (some had zero) reviews. The ones with reviews seemed to consist of five star reviews completely lacking details, or one star reviews describing all kinds of issues from the speed controller not working correctly to motors burning out once any kind of load was applied. Long story short, I decided the Chinese motors were questionable at best and to try to find a different solution. 

Thankfully I stumbled across some new old stock Bodine gear motors on eBay. These motors are manufactured in the U.S. and have a reputation for being really well-made and dependable and have been used in lots of grain mill builds. They’re also usually pretty expensive, retailing anywhere from $350 to over $500. Fortunately I was able to pick one up for a little over $100 and with free shipping. The model I got has a 15:1 gearbox, a final drive speed of 115RPM, and 68 inch pounds of torque. This is a slightly slower RPM than my old motor, but likely a lot more torque. I looked up the serial number on Bodine’s site and it appears this motor was a custom design intended to drive conveyor belts in a manufacturing setting. The motor can be run in both CW and CCW direction by wiring in a selection switch, but I decided to only run it CW. I did have to reach out to Bodine support for the correct wiring connections because since it was a custom spec motor, it used different wire colors than other gear motors in the same series. 

Bare Bones Mill

The bare bones mill is still the same Crank and Stein 2D mill that I used in my original build. Crank and Stein no longer sells this model, but they do sell a similar geared model. I replaced the original wooden mill top/hopper holder with a 3D printed one a few years ago. The printed one seems to be working great, so I decided to reuse it. I’m also reusing the hopper from the original build.

Mill Frame/Table

Like the previous version, the mill table is made from 1.5” square steel tubing. The top is made from 3/4” red oak plywood. I omitted the lower shelf where the motor was mounted and held the bucket to catch the milled grain. Instead, the bucket simply rests on the floor below the mill.

Build Details 

It’s a pretty straightforward build. The pictures show most of the details, but I’ve included some key points below:

• The mill and motor are mounted to the plywood top.
• The frame has six simple brackets for attaching the plywood top to the frame.
• The output and input driveshafts are different heights, so I made a spacer out of red oak to raise mill height. This spacer is permanently attached to the plywood top.
• The motor has a 3/4” keyed shaft and the mill has a 1/2” non-keyed shaft with machined flats. Linking the two was done using Lovejoy couplers and spiders. It’s important to note, these couplers will naturally handle slightly misaligned driveshafts, but you want to get them as close to perfectly aligned as possible to minimize wear and tear.
• I used polyurethane to seal all the plywood and wood surfaces.
• I welded three guides/stops to the frame to ensure the bucket is centered directly below the mill when milling. 
• I reused the same switch and power cord from the old mill.
  
• One other difference from the original build, this mill does not have casters. The “feet” are simply tubing plugs with rubber self adhesive pads.

To use, I simply slide a bucket under the mill table, fill the hopper with grain, then flip the switch. The motor seems to have plenty of torque and can be started full. Speed seems great and it does a really good job of breaking up the grain, separating it from the hull, while leaving the hull intact. For anyone interested, I use the default 0.045” gap. Historically, my efficiency is usually right about 83-85%. I’m pretty excited to have this mill back up and running. I have quite a bit of specialty grains on hand and plan to formulate recipes around them. I’ve also included a few build pics below.

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Experimental Thiol Beer

Today I'm brewing an experimental beer making use of one of Omega's Thiolized yeasts as well as Phantasm powder. Both of these products have been available in the homebrew world for awhile, so I realize I'm a little late to the party. I love hop-forward beers like IPAs, but I don't brew them all that often for two main reasons:

1. There is no shortage of fresh commercially brewed IPAs. In fact, the last time I went to GABF in Denver, at least half the menu boards in a lot of the taprooms listed so many IPA and NEIPA beers that it was almost hard to find anything but an IPA. I think you could argue the saturation level of IPAs has caused lots of issues for the craft beer industry, but I digress.
2. IPAs have a relatively short shelf life compared to many other styles. They can still be great, but I have a hard time finishing a keg before I start to notice hop character falling off, and that really bums me out. I tend to only brew IPAs when we have something going on where I know there will be more people around.

So those are the reasons why I don't typically brew IPAs often. So why am I brewing one today? Omega Yeast released their thiolized yeasts a while back and I'd always wanted to try brewing with them and just never got around to it. They recently announced that they're pulling these strains from the homebrew market, so if I was ever going to do it, it needed to be very soon. On that same note, Phantasm powder was released a while back as well. This product is from New Zealand and is made from white grape skins containing high levels of thiol precursors. I bought a small packet of Phantasm over a year ago with the intent of using it in an IPA, and I just recently bought an additional pound of Phantasm at a highly discounted rate (likely due to the Omega strains being discontinued). I'm curious as to how it could be used in sour beers as well, but bought it to be used in hop-forward beers. So here we are, about to brew an experimental "IPA-ish" beer.  

There is a lot of info about brewing with both products, so I'm not going to go too deep into either other than to say these products can bring out fairly intense fruity, especially tropical fruit character in your beer. A lot of the modern trademarked hops that are so popular today also feature similar fruity flavors and aromas. The thought is that pairing thiolized yeast with products like Phantasm powder can bring out tons of fruity character in a beer without having to use huge, arguably wasteful, hop additions...fingers crossed!

One thing that I look for in beers, especially hop-forward beers, is the complimentary layering of hop flavors and aromas. Almost everything I've read indicates the character from the thiolized yeast is pretty surprising, but at the same time they're not all saying they love it. I've heard some comparisons to body odor and others saying it's reminiscent of lemon-scented cleaners...neither is what I'm after here. I'm going to try employing a couple measures to help ensure I end up with something complimentary without it being a one note wonder thiol beer or something that wrecks your palate.  

This definitely is an experiment. I've read through numerous blog posts, including one from Scott Janish that got very technical. I've talked with some commercial brewers that have experimented with both products, one in particular that I really trust because he has a very balanced approach to the beers he brews. So here are my plans for the first attempt:

• Star Party (SP) is the strain I'm using and it's known to produce much higher thiol levels than the first thiolized strain that Omega released, Cosmic Punch (CP). CP is reportedly around a 5x multiplier of thiols, whereas SP may be up to a 300x multiplier. I'm going to try using a blend of US-05 and SP to restrain things a bit and see where that gets me.  
• Normal dosage rate of Phantasm powder is between 1-2.5oz per 5 gallon batch. I'm going with the low end at 1oz for this batch.
• According to what I've read, bract (vegetative matter) from hops can negatively impact thiols, especially when added via dry-hopping, more so late vs. early in the fermentation process. I'm using a reduced amount of Phantasm powder and a blend of yeasts, but I'm still hoping for some noticeable thiol character, so I'm going to try using all Cryo hops (reduced bract) without any dry-hop additions in this beer. There will be a small hop shot addition for bittering, flame out additions, and whirlpool (sub isomerization) additions.
• I've seen a few comments indicating a slightly sweeter beer works better with thiolized yeast. I've also seen that some have indicated the malt profile seems to disappear. Because of this, I'm shooting for a water profile more typical for a NEIPA with a higher chloride to sulfate ratio to emphasize malt character over bitterness.

The grain bill for this beer is based on Juicy Bits from WeldWerks, but I've changed up the hop additions substantially from the published recipe I found. So just to be clear, this isn't intended to be a clone recipe, this is just what I thought might be a good base beer for trying this experiment. Here's the recipe as I'm brewing it today and I'll be sure to post follow-up comments after tasting.

Target OG 1.062

Target FG: 1.012

IBU: 46

ABV: 6.5%

3.5625# Proximity 2-row Pale Malt 

3.5625#  North Star Pilsner Malt

0.875# Rahr Dextrine Malt 

0.625# Flaked Oats

0.625# Flaked Wheat

0.625# Rahr White Wheat Malt

1g BrewTan B (Mash)

6oz Dextrose (Boil)

2ml Hopshot (60 min)

4.66g BCAA (10 min)

Yeast Nutrient

Whirlfloc

9g Mosaic Cryo (Flameout)

9g El Dorado Cryo (Flameout)

1oz Phantasm (Whirlpool)

19g Mosaic (Whirlpool, after temp is below 160F)

19g El Dorado (Whirlpool, after temp is below 160F)

Blend of US-05 and Star Party 

Water Profile using Epsom Salts and calcium chloride 

250 chloride

80 sulfate

Mash at 149F, 90 minute boil, chill to 65F, ferment at 67F.

Water Profile

Target Water Profile
Ca	Mg	Na	SO4	Cl	HCO3
141.1	20.9	0	82.4	249.7	0

To 10 gallons of RO/distilled water, add:

• 19.6g Calcium Chloride
• 8.0g Epsom salt

Brewing Notes

No real issues, although I forgot to take my pre-boil pH and gravity reading because I was making some minor changes to my chilling hoses. On that note, my chilling setup worked much better this time. I chilled down to about 90F before turning on my prechiller. This time I was able to chill down to about 71F. 

I also dialed the measured boil temp down to 209F on my controller. This gave me a nice rolling boil with less boil off. I still ended up with a little less than 5 gallons in the fermenter and one extra gravity point over target. 

This is the first brew session with my re-built and upgraded grain mill. I'll be creating a post for it in the not too distant future. In the meantime, here's a link to my original grain mill build. 

Session Readings
Beginning mash pH	5.09
Ending mash pH	5.06
1st running gravity	19.2 (1.077)
Pre-Boil gravity	X (missed)
Pre-Boil pH	X (missed)
Post-Boil gravity	15.9 (1.063)
Post-Boil pH	4.92

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