Monday, June 29, 2009

Make your own grain mill for $25.00!

Okay, so now that my first "homemalted" brewing attempt was a complete failure, I have assessed my procedures and have come to the conclusion that poorly milled grain was the culprit. I really want to mill these gains properly, so I've been looking online to try and find a cheap alternative to the usual homebrew mills that run between $125 - $200 dollars. I was recently happily surprised to find this blog entry that describes how to make your own grain mill at home for about 20 bucks! So, I proceeded to make a cheap grain mill and will now relate to you my experience.

First, I found the nearest Michaels Craft Store, but you could probably go to any craft store if there isn't a Michaels in your area. I purchased this "pasta machine", which is designed for making thin layers of clay for crafts. It cost about $24. I brought it home and my 15 month-old son Evan tried to steal it from me while I was taking this picture:

Here's a picture after I took it out of the box (it comes with a hand crank and a clamp for attaching it to a table):

Next I turned it over and removed the base:

The "pasta machine" has two sides, one with a knob to adjust the width of the rollers, and one with the entry point for the hand crank. The hand crank side has an exposed screw, so I unscrewed it and removed that side:

Next, I removed the two bolts inside, which turned out to be 10mm in size, and then the end popped off and I was able to remove the top and bottom guides, exposing the rollers:

When this thing is finished, your basically going to pass the grain between these rollers to crush it. The problem is that the rollers are perfectly smooth and designed for dough or clay, so grains will just slide around on top and never pass through. You need to rough them up so the grain is drawn in properly. The blog I mentioned above tells you to take apart the entire apparatus to rough up the rollers, but I decided not to do so, since it looked like a major pain in the ass to remove the spacing knob, and why should I put myself through that? I had already succeeded in removing the guides and easily had enough room to roughen the rollers. I used a hack saw to scratch them, then I beat the crap out of them with the claw side of a hammer. Here's a picture after this process (it didn't come out that clear, but you get the idea):

I put everything back together, but left off the bottom guides. Are they really necessary? I don't think so. I think they are there just to guide the pasta or clay so that it comes out the side instead of straight down, but for our purposes it is better if the grain actually falls straight down. Then I clamped the hand crank to my work bench and used the hack saw to cut off the tip, which I could then place into my variable speed power drill to operate the mill without any effort! (In this picture I've already placed the tip into my drill):

Next I found a scrap piece of plywood and an old "Homer" bucket in my garage and cut the plywood down to fit squarely over the bucket:

I measured the mill and then drew out a rectangle on the plywood that would allow grain to pass into the bucket after being crushed. Then I cut out the hole using a drill and hack saw (the wet spots are from my sweat - I was working in my garage and it was 100 degrees out that day):

I found four screws that were long enough to make it through the plywood and into the mill, and slightly larger in diameter than the existing holes in the mill where the base used to be attached. I figured I could force them into the existing holes for a nice snug fit. So I then pre-drilled holes through the plywood and pushed my screws through just enough so they were peaking out the other side.

After turning over the wood, I placed the mill on top and used the protruding screw tips to locate the base holes. Once everything was lined up, I turned it back over, applied firm pressure with my foot, and powered the screws in. They fit nice and tight so the mill ended up very firmly attached to the wood:

Lastly, I cut a small piece of wood to fit over the top of the mill, and cut the end off of a 2-liter seltzer bottle to form a makeshift hopper. I traced the end of the bottle onto the wood, which turned out to be about 1 inch in diameter. Then I drilled a hole and forced the mouth of the bottle into it. It was so snug that I didn't even bother to use any glue. But I did glue the wood to the top of the mill with this super strong, waterproof cement that I have used in the past to fix up mash tuns. Before I glued it on, I got the idea to scratch up the rollers even more by turning on the drill and then dragging my bit across the rollers. Worked great! One tip though: you have to put the drill in reverse, otherwise the bit will jam in the rollers!

That's it! After that I let the glue dry overnight, and then tested it out the next day. I had to adjust the roller width a few times until I found out that setting # 3 worked best. The only drawback is that it is quite slow. It took me about 30 minutes to completely mill 10 pounds of grain. That is a really long time when you are kneeling down holding a drill. I thought maybe if I cranked the drill up to full speed it would be faster, but it actually worked better at a slow, steady pace. At high speed it feels like the pasta maker is going to literally fall apart, and also less grain gets trapped in the rollers. Here's the first trial of the new "el cheapo" grain mill:


  1. Wow! Sweet article! Any idea how to beef it up so you can crank out more faster?

  2. The key to getting maximum speed is to make sure the rollers are really rough, and to adjust the distance between them properly. At 4 it grinds really fast but doesn't crush the grains that well, and at 3 it crushes perfectly but goes really slow. I've tried holding it between the two numbers, or just milling it twice on 4 with pretty decent results. After I wrote this post I eventually got a bigger mill for full batches and gave the small one to a friend who still uses it to this day for steeping and partial mashes! Thanks for the comment!


  3. Are the rollers solid or tubular? Thinking I could knurl them on a lathe.

  4. they are not solid if i remember correctly

  5. If you built a hopper so the grain flows all the way across the rollers I think it would go a lot faster- like a big "V". I have a very small version of a Corona mill and I think that is the reason it is slow- small amount of area the grain touches.

  6. Hey Charles thanks for the tip! You know when I built this thing I basically just tried to do it as cheaply and quickly as possible and with the intention of using it only for a pound or two so I could experiment with toasting small amounts of grain. I think a hopper might help distribute the grain against the rollers, but you still have to deal with the fact that the rollers themselves can't really process the grain as effectively as ones that are properly knurled and spaced, like in a professionally-built mill. If you try building a hopper I would definitely be interested to hear about how it functions though.

    Thanks again for the comment!

  7. the most motivated stoner ever.. turns an old GB into a fucking grain mill.. kudos to you sir.

  8. I just finished altering my rollers for the same exact model. I used a tungsten carbide bit with my dremel and made grooves in it like a knurled roller. They aren't as pretty as the machined ones but they don't have to be, just functional.

  9. I am in the middle of my first malting experience. Got my barley from Amazon as well. It just started to sprout this morning. Thanks for the information and advice. I have just recently gotten into all grain brewing. I am hoping for a backyard brew this summer. I have planted some barley in the back yard that is growng nicely. I also have hopps. This is the second year for the hopps so they should produce better this year. Last year I got enough to dry hop a couple of batches.
    I also did the pasta machine roller mill. I made lines the length of the rollers with my Dremel and a grinding wheel. Works pretty good.
    Thanks again for the info.