There are plenty of proven homebrewery designs out there, amongst all of the ways they differ, the number of required brewing vessels is perhaps the most obvious. My new homebrewery is being built as a two vessel system. On my search of two 20-25 gallon tri clamp outfitted brew kettles in Canada, I didn’t come up with much. One option I considered was to buy standard brew kettles without tri clamps, and then perform the necessary modifcations. This ended up being quite costly, all parts and labour considered. Beyond being outfitted with sanitary fittings, and meeting my volume specifications, I was looking for brew kettles with internal volume markings, and heavy gauge 300 series stainless steel construction. Even after expanding my search to include the US, there were no off-the-shelf kettles that fit my budget, timeline, and specs.
In walks Spike Brewing. This Wisconsin based business offers kettles which on the surface look to me like the popular SS Brewtech kettles on steroids. What’s more, these guys offer custom kettles! I excitedly submitted brew kettle designs to obtain a quote. In a twist of fate I was going to be near their Milwaukee based shop at the end of July for a conference… since Spike Brewing doesn’t ship outside the US, this turned out to be a very important detail.
As always, this article continues without any affiliation to the company discussed (until some forward thinking company decides to sponsors my brewing adventures).
I was busy with other aspects of my brewery when I got home from the conference, but I’ve now had a chance to take a close look at my purchases. These kettles are quite hefty and appear well built. My one 20 gallon kettle clocked in at 10.14 kg (22.35 lbs) without its lid, or any fittings. The stainless on these kettles is well polished and without gouges from the machining process. The rims are rolled nicely, and the silicone coated handles are a nice touch. Handles are spot welded then riveted. Their volume markings are clear, and are in half gallon increments.
The welds are high quality, shown below. The use of this as the featured image of this post was metaphoric of course… there’s light at the end of the tunnel… er… tri clamp port for this brewery build.
The ports appear to have been punched, then “dimpled” to match the diameter of a tri clamp ferrule before welding. There are small marks from this process on the outside of the kettle. There doesn’t appear to have been any splitting of the stainless or unequal pressure applied from the process; all ports appeared to have been pulled smoothly, and are straight.
The dimensions of these kettles are stated to be 21.4″ high, by 17.7″ wide. I found the height measurement to be exactly that. The width, or kettle diameter I calculated back from a circumference measurement of 1426.5mm (56.16″) to be 454.1mm (17.88″)… within a reasonable margin of error. Spike brewing specifies a 17.5″ internal diameter… From my calculations, using the stated 1.2mm wall thickness, the internal diameter would be 451.7mm (17.78″). I only go through the process of measurement validation for the purposes of obtaining a false bottom. I trust their measurements over mine here. I used a cheap fabric measuring tape the OMNR (Ontario Ministry of Natural Resources) provided me for filling out fish surveys for the circumference measurement, not exactly a high precision instrument.
A “domed” bottom design provides a 1/2″ lip or so all the way around the base of the kettles for a false bottom to sit on. This designs reduces the need for a false bottom that fits the internal dimensions of the kettle exactly, and also gives you minimal mash tun dead space if you decide to use it. Spike Brewing manufactures their own false bottoms for these kettles of course, but these wouldn’t work for me as they are designed for their dip tubes, and I’m sticking tri clamp fittings throughout my brewery. I expect any false bottom between 17″ and 17 7/16″ diameter will work well here if you are planning on using the lip in these kettles, and between 17 3/8″ and 17 7/16″ if you do not.
If you are getting kettles custom built by Spike, be aware that all measurements are from the lip in the bottom as described above, to the centre of the ports. The lip approximately 3/4″ from the very bottom of the kettle. The lowest they install 1.5″ tri clamp ports is 2″ high. In other words, it is 2 3/4″ to the centre of the ports from the very bottom of the kettle, or 2″ from the very bottom of the kettle to the very bottom of the 1.5″ tri clamp ports.
Moving on to the volume markings: these continue up the inside of the kettle stopping about 22mm from the rim. There appears to be 25.83mm between every gallon marking (measured by finding the distance between the 10th and 20th gallon marking, and dividing the distance by 10). By my calculations, using the 17.5″ internal diameter that Spike Brewing provided me with, we find there are 4.008 litres (1.06 gallons) within each 1 gallon increment. Not bad, and almost dead on if would like to assume Spike Brewing is showing measurements of boiling wort after cooling loses (wort is about 4% less dense at boiling than it is at room temperature). I’m not exactly sure if this is the intention or not, and if it were I’d prefer that the volume markings were accurate at room temperature, but I think I can work around it that. No no, scratch that… my system MUST measure brewing quantities in moles!
Using my weight scale, I wanted to find what the actual volume was at the first volume marking of 2 gallons. My mash tun with valves weighed 13.384 kg. With water filled to the 2 gallon mark, it weighed 21.834 kg. The difference in these weights, 8.450 kg is the volume of water in litres (yay metric system) and 2.23 in gallons. What I think is going on with this discrepancy is that the volume markings do not take the domed portion of the kettle bottom into account – and that this is assumed to be dead space. From my calculations, the true volume in these kettles at the 20 gallon marking is actually 21.43 and volume at the rim of the kettle is 22.49 gallons. I’d assume this level of accuracy is pretty standard amongst volume markings in other kettles and sight gauges.
It’s good to sort out all of these details for when you are setting up an equipment profile in beersmith or similar… and so you are able to sleep at night if you are in anyway like me. Set the kettle deadspace to be 0, and I think that will be close enough for 99% of homebrewers for using etched volume markings from 2 to 20 gallons.
That’s all I will say about these beautiful kettles for now! The final segment of my brewery build saga is to come..!