Homebrewing DIY: Homemade hop blocker


My last article showed how I installed a weldless bulkhead and spigot on my brew kettle. A critical piece to using a spigot is keeping the stuff in your wort from clogging the diptube. If you have a false bottom on your kettle, you are all set. If not you need a screen of some sort. Sure you could buy one, but where is the fun in that? If you spend the time to make one, you can save some money and get something tailored just for your setup.

I took a lot a ton of pictures during my build, and I’ll do my best to explain them, but if you need more visual details, check out this video. It’s what got me going on this project, and what I turned to when making mine.

The parts

After watching that video, I knew I wanted to build one. I went to the McMaster website and ordered my materials:

  • 28×28 Mesh Stainless Steel Wire Cloth – Product #85385T77 ($6.5/sqft)
  • Stainless Steel Wire – Product #8860K11 ($9 for 1/4-pound roll).

Type 304 Stainless Steel is corrosion resistant steel, and the industry standard for food-based equipment. This mesh is flexible enough to mold, but its strong enough to handle heavy loads of wet hops without collapsing. The 28×28 mesh count means that there are 28 lines of steel per vertical and horizontal inch. This means 784 holes per square inch of the screen. I ended up buying a 12″×24″ sheet just in case I messed up my first attempt. Compared to the cost of the screen, the wire seemed more expensive, but 1/4-pound roll is a lot of wire. Overall, the total bill with shipping was $27. Enough stuff to make 2 blockers.

The tools
  • Scissors
  • Tape
  • Paper
  • Pliers (needle-nose are best, since they have a lot of surface area)
  • Awl (or something to push holes through the mesh)


All the stuff

Prototyping with paper

Since I knew this build was going to take some time and effort, I wanted to avoid any obvious mistakes by making a paper version before starting the final product. In my first build, I ended up having to hem the end of mine to be able to install it my my brew pot. This time, I was going to make sure it fit before starting with the steel.

The process is pretty straight forward. I took some paper and cut it to the size of my screen. Then, since I’d be folding over the edges of screen to avoid fraying, I cut off about 1/2″ from the length and width of the paper to simulate the loss of surface area. Finally, I grabbed some tape, and started folding/taping the paper to the shape I wanted.


Paper: ready to mock with

This was a good exercise to see how much surface area I could get with my sheet. The more surface area the better, but I wanted to make sure I’d have enough space between the walls to keep them from pressing on each other when buried in hops. The screen is strong and will withstand a lot of weight, but just folding the screen in half would make an easily-cloggable screen. Another thing I had to consider was the position of my diptube, and how I wanted it to fit into the screen. I made sure to ‘install’ my paper prototype in my kettle to make sure it would be easy to get on and off.

With my prototype, I went with a triangular shape much like the video above. The walls have enough separation and there is a lot of surface area.


The basic triangular shape

I considered having the diptube insert at one of the corners, but I also wanted to keep the large face of the screen against bottom of the kettle. I ended up putting the hole in the smallest face. With my paper, I fashioned a collar for the diptube by cutting an inch of one side of my sheet. With the strip of paper, I cut it into a few pieces: one to roll into the collar, and a couple more to help connect the collar to the larger structure.


the collar pieces

I made 4 1/4″ cuts up one side of the tube equidistant from each other. Then I folded those pieces outward to act as flanges for connecting to the body.


The collar cut and flanged

Then I cut holes in my two remaning pieces and sandwiched them on either side of the flanges. This gave more surface area for attaching the collar, and would help to cover some the sharp edges of the steel flanges.


First piece on


Second piece on


The finished collar design

With the collar mocked up, I put the body of the prototype in my kettle and marked where the diptube would connect to it. Then I just cut out a hole and slid the collar in. Viola:


The completed prototype

Prepping the screen

I did not take apart my prototype and use it as a direct reference for the final build. I knew that I would need to deviate a little from the prototype’s fold lines, since sewing would use some edge space (you’ll see). However, I did cut down the sheet to reflect the inch I took off of one side for the collar materials.


Cut down to size

Making the folds

I started by making the folds around the edges of my sheet; these are the folds that will prevent fraying.


Rough edge


Folded edge

These were tougher folds to make, because they are so close to the edge. I used a ruler as a straight-edge and, with the screen on a table, bent the screen up against the ruler. Once I get the fold started it was easy to pinch it over with my fingers. Finally, I used some pliers to put a solid crease in the folds. I made sure to make all the folds in the same direction, and ended up with all the rough edges folded in to one side.


Setting the fold line


Starting the fold


Crimping with pliers


The edges are cleaned up

Now with the edges prepped, I started making the main folds- keeping the rough edges on the inside of the body. I used a ruler to help get straight lines, but I didn’t crease anything just yet.


pinch two opposite corners


initial folds

I started to firm up the folds by just pinching lightly with my fingers. As the desired fold lines became more apparent, I used the pliers to lightly crimp the corners to mark them being careful not to pinch them down really tight, because I might need to adjust them slightly when the sewing starts.


A light crimp


Folds complete

Fabricating the diptube collar

Before starting on the body of the blocker, I built the collar. I’ll need to install it before starting to sew up the body. I took about a 3″×1″ piece of screen and folded-over and crimped the edges on the short and long side.


Collar tube piece prepped

Then I rolled it around my copper diptube, keeping the folded short edge on the outside. I let it spring back a little bit so the opening was wide enough to allow the tube to slide easily in and out.


Measure circumference with the diptube as a guide

With the circumference nailed down, I was ready to start sewing. I took the awl and poked a hole though the layers of the collar. Then cut about a 2 foot length of the stainless steel wire and started sewing.


Using the awl to make the guide hole

To start the seam, I wrapped the wire through the guide hole and around the edge a few times, and then pulled it tight with my pliers.


Starting the seam

Then I just sewed down the length of the collar until about 1/4″ from the bottom. I used the awl to start all the holes. Trying to finess the wire through the mesh without a guide hole is a big waste of time.


Sew up the collar

Next, I took my scissors and cut the 4 slits in the collar (the end that is not sewn). Just like with the paper version.


Cutting the flanges

With the 4 cuts made, I folded out the flanges and cut the holes in the two rectangular collar pieces. I stacked them together and shoved the awl through where I wanted the holes to be. Then I used scissors to cut the hole to about the right shape, and rounded them out by sticking my pliers in them and twisted them around.






Widening with pliers

Finally, I sandwiched the rectangular pieces around the flange.


Finished collar

Installing the diptube collar

I looked at the prototype to check the placement of the collar hole. I sized it up by pressing the collar against the body, and stuck the awl through the middle to spot the hole.


Use collar as a guide

I cut/widen the hole as necessary, and kept the sharp edges pointing inside the body. Then I slid the collar into place.


Collar in place

Next, I trimmed the overlapping surface area from the collar’s rectangles.


Overlap. Removed

Finally, I attached the collar by sewing through the wall of the body and the rectangular collar pieces. I double threaded mine, but you don’t have to.


Collar sewing started


Collar sewing finished

After the brief bit of sewing, I trimmed and folded-under any rough edges from the backside of the collar. The collar is done!


cleaned up the inside

Sewing (and sewing and sewing and sewing) the front

Now here is the tedious part… a couple hours sewing. I started sewing at the peak. Taking about a 3.5′ length of wire, I held two sides together with my fingers and poked the first hole with the awl. I wrap the wire through the hole a few times and pulled it tight with the pliers. Then I trimmed and tucked the excess wire inside the body of the blocker. Finally, I started sewing down one of the short sides of the blocker, using holes about 1/4′ apart.


starting the first side

After looping through each hole, I used the pliers to pull the wire tight. Once I hit the corner, I crimped it down hard with the pliers, and ran the wire around the last hole a few times before starting back up the seam. I criss-crossed the first stitch on the way back up.


Criss-crossing back up

I liked the criss-cross pattern as it let me get away with fewer holes because I could space them farther apart. Less holes means less time sewing. Once I got back to the peak, I proceeded to do the other short side with the same length of wire. Eventually, the front was done!


the front is all done


Now, let’s do the spine

Sewing (and sewing and sewing and sewing) the spine

More of the same. I started at the stop, and sewed down the spine, criss-cross on the way back up. Once I got back to the peak, I threaded my wire through each of the three walls a couple of times and trimmed/tucked the remaining sprig of wire inside the blocker.


sewing the spine

Adding a hose clamp

I added a hose clamp around the tube of the collar. This is a great addition for securing the diptube to the collar.


Hose clamp added


Whew, if you followed along at home, congrats, you made it. And you have an awesome hop blocker that you can be proud of!



One Response to 'Homebrewing DIY: Homemade hop blocker'

  1. Todd Scott says:

    I love your design and the source info for the material. Thanks so much! Cheers, Todd

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