Note: the following is an unbiased review of a product I purchased myself. This is not a sponsored review.
Update: since this review was published, Spike now offers a black neoprene jacket and a lid with three 1.5” TC ports.
Fermentation is the most important step in the process of brewing beer. Without it, you simply wouldn't have beer at all. As homebrewers learn and progress in their craft, improvements to their fermentation practices and equipment will have substantial effects on the quality of the beer they produce.
Long used at the professional level, cylindroconical fermenters (commonly referred to as simply "conical" fermenters) have become more common at the homebrew scale in recent years. There are a number of offerings in the market, ranging from relatively inexpensive plastic conicals up to stainless steel. The body of such vessels is shaped in a cylinder at the top, then tapers into a cone at the bottom. This allows for trub and yeast to settle out and be dumped (or harvested, in the case of yeast) through a valve at the bottom of the cone. Because the yeast and trub collects in this narrow space at the bottom of the fermenter, it reduces the surface area of the yeast that comes into contact with the beer.
At some point in their life cycle, yeast cells will undergo autolysis. As the membranes inside the cells deteriorate, they will eventually burst open and their contents can flow into the beer, which can cause off-flavors above a certain threshold. These cell contents can also attack the proteins in the beer, impacting head retention. Autolysis happens simply as yeast cells age, but can be driven by other factors as well, including abrupt changes in temperature. As such, having the ability to minimize surface contact with yeast cells and periodically dump them can be beneficial.
Unitanks are a subset of conical fermenters, which are rated to withstand a certain amount of pressure. In the case of Spike Brewing's Conical Unitank, the pressure limit is 15 PSI. The ability to withstand pressure offers additional benefits.
For one, beer can be fermented under pressure (a spunding valve would be needed - sold separately and not offered by Spike Brewing at this time). Fermenting under pressure reduces the yeast's production of esters and fusel alcohols, which results in a less complex, cleaner-tasting beer that would be desirable for some styles, such as lagers.
Another benefit is the fact that the beer can be carbonated in the same vessel once fermentation is complete. This can be done simply by applying CO2 head pressure (with Spike's optional gas manifold bundle), as one would do in a keg; however, it can be greatly sped up by using a carbonation stone (which Spike Brewing offers as an optional accessory). This reduces the carbonation time needed from about 5-7 days down to roughly 24 hours.
Another huge benefit is the ability to transfer the beer from the fermenter to a keg under pressure (Spike offers a closed pressure transfer kit as an optional accessory to facilitate this). This process maintains a closed system and prevents the introduction of oxygen into the beer. Oxidized beer presents flavors such as cardboard or sherry, and is undesirable.
So, conical unitanks offer a number of benefits, but how does Spike Brewing's offering fare? In this review, I'll be looking at the CF10, which can be used for 5-gallon or 10-gallon batches. Spike also currently offers the CF5, CF15, and CF30 models in their unitank lineup.
Ease of Use: 4/5
A fermenter in this class will inherently be more complex to use than a simple glass carboy; however, Spike provides good documentation to help conical novices get up and running. Furthermore, a number of design elements make the Conical Unitank easy to work with.
All ports on the fermenter use tri-clamp (TC) fittings, with one 4" port and one offset 1.5" port on the lid, three 1.5" ports on the front, and one 2" port at the base of the cone. TC fittings are the industry standard and allow for easy cleaning, sanitizing, and assembly. A number of accessories can be added on to the various ports as well.
The larger 2" port at the bottom allows for easier dumping of yeast, trub, or hops from the fermenter (in the case where the beer is dry hopped), versus some competing options with a 1.5" TC dump port.
The lid of the fermenter is completely removable, attaching with a band clamp. This makes it very easy to clean the inside of the fermenter with a brush. If preferred, a spray ball can be used in the 1.5" TC port of the lid to clean the unit in place. I've used the spray ball to good effect in conjunction with Blichmann Engineering's RipTide Pump.
Additionally, etched markings on the inside of the kettle make it a cinch to hit volume targets.
Quality: 5/5
The build quality of the fermenter is excellent. The unit is 1.2mm 304 stainless steel and feels very sturdy. The base unit offers great functionality, and it can be expanded through the purchase of a variety of accessories. The welds on the unit are high quality and look great.
Effectiveness: 4/5
I've run several batches of beer through the fermenter and have always produced a consistent product. The bottom port is effective at removing trub, yeast, and hop matter.
Furthermore, I've had good results with the unit maintaining pressure. In one instance, there was a leak out of the 4" TC port on top, but I was able to re-seat the gasket and that solved the problem. I used a different gasket in subsequent batches.
One of the selling points of Spike's fermenters (and kettles for that matter) is that they offer some amount of future-proofing. If you brew 5-gallon batches of beer, you can purchase the CF10, which is designed for 10-gallon batches but allows for half-sized batches to be produced as well. This is accommodated via strategic placement of the ports on the front of the kettle, allowing them all to be submerged even when the unit is only filled halfway with beer.
This mostly works well; however, I did notice that half-sized batches were more difficult to cool and maintain crashing temperature using Spike's optional TC100 Temp Control System. So much of the chilling coil is exposed to air, rather than liquid, that it just doesn't keep the beer quite as cool.
One other consideration has to do with the touted carbonation feature of the tank. In my testing, the lowest I have been able to chill a 10-gallon batch of beer using a glycol chiller is 37.1˚F. The tank has a maximum pressure rating of 15 PSI. This means that the maximum carbonation level you can achieve in the unitank is 2.92 volumes of CO2. For sure, this will cover the appropriate carbonation level for the majority of beer styles; however, a number of styles can have carbonation in excess of 3 volumes of CO2 and would require a different means of carbonation, such as in a keg after transferring from the fermenter.
I brew a gold-medal winning Blackberry Berliner Weisse each year and cannot carbonate it in the fermenter, which is disappointing.
These highly-carbonated styles are as follows:
· Australian Sparkling Ale
· Belgian Blond
· Belgian Dark Strong
· Belgian Dubbel
· Belgian Golden Strong
· Belgian Pale Ale
· Belgian Tripel
· Berliner Weisse
· Biere de Garde
· California Common
· Dunkles Weissbier
· Fruit Lambic
· German Pils
· Gose
· Gueuze
· International Amber Lager
· International Pale Lager
· Kölsch
· Lichtenhainer
· Piwo Grodziskie
· Roggenbier
· Saison
· Trappist Single
· Weissbier
· Weizenbock
· Witbier
Cost: 4/5
Spike's unitank line of base models range in cost from $550 to $1,450. There are plenty of accessories available, which can further increase the cost by up to another $800 (or more).
While this is much more expensive than an offering such as KegLand's FermZilla, it is comparable in price to Spike's main competition in the stainless market, Ss Brewtech.
Buyers receive a host of professional-grade features, along with the durability and cleanliness of stainless steel.
Overall: 4/5
I purchased the CF10 conical unitank over a year ago and have been very pleased with it. It is not perfect, but the range of features it offers is impressive.
As mentioned above, for many homebrewers thinking about a stainless unitank, the decision is going to come down to Spike Brewing or Ss Brewtech.
As much as anything else, style must play a part in the overall consideration. While I like the design of the tank itself, the grey neoprene jacket that comes with the TC100 Temp Control System is not doing it any favors. It is a far cry from the sleek look of Ss Brewtech's ubiquitous black neoprene jackets and all-stainless butterfly valves. I hope that Spike may offer a black neoprene option in the future.
The Ss Brewtech unitank also offers an extra port on both the front and the top of the unit, for two extra ports total. This offers greater flexibility for attachments. While the Ss Brewtech tank has the same 15 PSI operating pressure as the Spike unit, it is rated for 30 PSI, giving it more flexibility for carbonation if an after-market pressure release valve is used.
That said, the ease of cleaning cannot be overlooked with Spike's unitank. The removable lid makes that a breeze. Some accessories are higher quality as well, such as the carbonation stone, which is enclosed in a tube and has a ball lock post for a better gas connection than merely a hose barb. The 2" TC port on the bottom also allows for easier dumping and for the attachment of a larger sight glass for inquisitive brewers. The number of usable ports on the fermenter can be easily increased by purchasing tees or other connection pieces elsewhere.
The base model is substantially cheaper than Ss Brewtech's option, and allows for a more accessible entry point with room to expand later. For my money, Spike's offering is certainly worth the price of admission.