Brewing In A Spike Conical Fermenter

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Note: Brewing with electricity is inherently dangerous. Be safe and speak with an electrician to ensure you have adequate GFCI/GFI (ground-fault circuit interrupter) protection. Always use caution and be mindful of your surroundings and processes.

The advent of the BrewBuilt™ SlingBlade heating elements, which are crescent shaped, created an interesting possibility. They could be used to transform a Spike CF15 conical fermenter into a self-contained brewing system. This is done by inserting the 10-gallon sized SlingBlade (3,750 watts) into the conical’s racking port and angling it up along the side wall. The racking port then goes into the sample port instead.

Once the wort is brewed in the conical, it may be sealed up and fermentation can proceed as normal. Thus, all aspects of the brewing process may be handled within one vessel. The concept here is not a new one, and there are existing commercial options available; however, the Spike CF15 has some unique design considerations which are advantageous when compared to other fermenters on the market. Some of these include:

• A removable lid that extends all the way out to the conical wall.

  • This allows for the lid to be removed during the boil for the best possible removal of DMS.

• Three tri-clamp ports on the front of the conical and three more tri-clamp ports on the lid.

  • This allows for the following accessories to be used on the front of the fermenter: racking arm, Slingblade heating element, RTD temp probe (controls mash temperature).

  • The following accessories can be used via the lid: 20" thermowell (controls fermentation temperature), airlock or spunding valve, plus one port to spare (could be used for hop additions).

• The diameter of the Spike CF15 kettle is very comparable to Spike's 15-gallon kettle. As such, accessories like the 15-gallon Solo basket and the Steam condenser lid work well.

  • It should be noted that the 15-gallon Solo basket will not work well in any other Spike conical besides the CF15. The added height of the CF15 (compared to something like the Spike CF10) allows the basket to be used without bottoming out on the fermenter cone or the temperature probe.

• Flexibility to ferment batch sizes anywhere between 5 and 15 gallons, although I recommend minimum batch sizes of at least 6.5 gallons for best results to ensure the thermowell is sufficiently submerged.

I first became interested in experimentation with this system due in large part to the setup of my home brewery. I brew in a basement with no floor drain, utility sink, or direct outdoor access. As such, brew day cleaning can be a real chore. This involves me filling numerous buckets and hauling them across the basement and upstairs to drain in the kitchen sink or yard.

As of the time this post was written, I have been brewing exclusively in my Spike CF15 and CF10 conical fermenters for approximately a year and half. I have experimented with a number of different configurations. I enjoyed the process so much that I ended up selling my Spike Trio kettles. That said, while this system offers many benefits, there are also some drawbacks. As such, it may not be ideal for every brewer, but it is certainly worth thinking about when considering an electric brewing setup.

Pros:

• The fermenter has a bottom drain.

  • Bottom-drain recirculation eliminates fine-crush grain pass-through in the Solo basket.

• No brew day kettle cleanup.

  • All that needs to be cleaned on brew day are the basket, chiller, and some fittings/hoses.

• Easier cleaning in general.

  • The fermenter can be cleaned in place (CIP) with a spray ball after fermentation is complete. This is more effective than CIP in a kettle due to the addition of the gasket, lid clamp, and bottom drain. I have found this to be easier on my back and on my body.

• Brewing 5 to 10 gallon batches in the CF15 means a blowoff tube basically never needs to be used due to the height of the fermenter.

• Minimal sanitization is needed.

  • All hoses, body fittings, and the fermenter itself are heat sanitized during the boil. Only the fermenter lid and any lid fittings need chemical sanitization. This cuts down on the use of chemicals and water.

    • While acid-based sanitizers (like Star San) are very effective at killing nearly all microbes, they do not have 100% effectiveness. Boiling, on the other hand, is 100% effective at removing any troublesome microbes, including Brettanamyces (which is a wild yeast strain that can be tricky to get rid of).

• The mash is insulated via the conical jacket.

  • Having insulation on the body of the kettle/fermenter is also a nice safety feature, reducing the likelihood of burns around a hot kettle, particularly with small children or pets.

• The fermenter can be used with casters and Spike's extended bracing shelf.

  • This gives the unit some mobility and can be helpful if it is desired to brew in one area of the room (such as by a hood/vent or window) but mount a pulley/wench in another area for raising the Solo basket (the grain basket). Be mindful that the fermenter can be top heavy. I recommend pushing it slowly from the base, not from the top.

• Your brewing footprint is smaller.

  • If you'd like to use a conical fermenter regardless, then you can free up or repurpose your hot side brewing space into something else, such as a packaging station for bottling and/or canning beer.

Cons:

• There is a greater amount of mash tun dead space compared to other single-vessel systems.

  • Due to the increased dead space, it is recommended to mash with the full volume of water and no sparge.

    • Lack of sparging will result in lower efficiency, thus more grain will be required.

  • More dead space can also lead to thicker mashes as more grain is used.

    • Thick mashes for high ABV/high grain bill beers can be addressed via a double mash (mashing some of the grain, removing the spent grain and adding more), mashing for a longer period of time (e.g., 90 minutes) or by adding additional fermentable sugars to the boil to boost ABV (e.g., dry malt extract, dextrose, lactose, or other sugars). Be mindful that something like dextrose will thin the body of the beer.

    • You can also adjust your boil method and/or boil duration to increase or decrease the volume of liquid in your mash.

      • Boiling uncovered will result in more liquid being boiled off, thus more water would be used in the mash. Boiling with a steam condenser lid will result in less liquid being boiled off, thus less water would be used in the mash. Likewise, planning for a longer boil duration would use more mash water and shorter boil duration would use less mash water.

      • For a smaller batch size, I would recommend to consider an open boil for at least 90 minutes, taking this into account in your recipe. This will give you a bit thinner mash and more liquid to play with. For a larger batch size, you may need to consider using a steam condenser lid and/or a shorter boil duration so that you can fit more grain without overfilling the fermenter. Due to the shape of the Solo basket, there is less relative dead space as the overall volume increases.

We can estimate the dead space of the CF15 by looking at an article on Spike's site regarding the dead space measurements in the Solo basket.

The CF15 is listed at 17" in diameter compared to 15.8" for the 15-gallon Spike kettle. The cylinder of the fermenter is also about 3" shorter, meaning there is less volume between the Solo basket floor and the bottom of the cylinder. With a kettle radius of 7.9" and a height of 3", that equates to approximately 588 cubic inches, or roughly 2.55 gallons less dead space in the cylinder of the CF15 compared to the 15-gallon kettle.

We also need to take into account the volume of the fermenter cone and the elbow at the bottom. I'll estimate that to be around 4 gallons. I am not going to worry about the larger diameter at each volume marker above the basket floor because that is rather marginal. In total, I'll roughly estimate that the dead space amounts listed by Spike at the above link will be 1.45 gallons more (4 minus 2.55) at each gallon marker when using the 15-gallon Solo basket with the CF15 compared to a traditional kettle.

Gallon Marker	Adjusted Dead Space (Estimated Gallons)
5.5	6.77
6.0	6.91
6.5	7.06
7.0	7.19
7.5	7.33
8.0	7.45
8.5	7.58
9.0	7.7
9.5	7.82
10.0	7.93
10.5	8.04
11.0	8.15
11.5	8.25
12.0	8.35
12.5	​8.44
13.0	8.53
13.5	8.62
14.0	8.70
14.5	8.77
15.0	8.85
15.5	8.86
16.0	8.98

Other Considerations

Because the racking arm of the conical must be moved up one port in order to accommodate the heating element, I added approximately 4" of silicone tubing onto the end. This amount allows the racking arm to pull beer out from further down into the conical without obstructing its movement when rotating the arm during fermentation or when transferring beer to a keg.

Because the wort is not being transferred to another vessel for fermentation, an immersion chiller is the ideal chilling solution. I like the JaDeD HYDRA™ for its efficiency. It fits well in the fermenter. If the heating element is angled up along the right wall (when facing the front of the CF15), them the racking arm can be angled up along the left wall and the chiller can rest on it.

I also recommend using a hop spider to keep hop material out of the fermenter. It can be removed after the boil is complete and before you start to chill the wort. During the chilling process, wort can be whirlpooled around the chiller. Once close to the desired temperature for yeast pitching, the bottom valve can be closed. Trub and any other matter will pool down at the bottom of the fermenter, in the elbow below the cone. I then typically pump out approximately 1/2 a gallon of the wort into a bucket to collect that trub and keep it out of fermentation.

My preferred means of mash temperature control is via a 1.38"/35mm 1.5" tri-clamp RTD temperature probe from The Electric Brewery. This short probe is necessary so that it does not make contact with the Solo basket during the mash. It provides very precise temperature control.

Speaking of the mash, I use the following parts for mash recirculation: 15-gallon Spike+ Pickup Tube - Center, Sparge Diffusion Plate - Quick Disconnect Male, Quick Connect Fitting - FQC x Barb, Silicone Tubing.

An electric hoist can make it much easier to lift the Solo basket. I use this model of hoist in conjunction with these one-foot cables.

When it comes to powering your system, there are a lot of potential options. As indicated above, brewing with electricity is inherently dangerous. Be safe and speak with an electrician to ensure you have adequate GFCI/GFI (ground-fault circuit interrupter) protection. Always use caution and be mindful of your surroundings and processes.

I built my controller for my prior Spike Trio using a kit from Electric Brewing Supply. You can see my thoughts on that build process and the controller in this post. That controller is a bit overkill for this setup since it is designed to be able to power two different heating elements, but they also offer a Complete 30a BIAB Kit. If you prefer, you can also purchase one of their controllers pre-built, such as this.

Other controllers that may be worth considering include one of the Wort Hog models from High Gravity Fermentations or the 240 volt model from Clawhammer Supply.