Comstock-Castle CC-GDF30 Floor Model Doughnut Fryer, Natural Gas, 120,000 BTU

Comstock-Castle CC-GDF30 Floor Model Doughnut Fryer (Natural Gas, 170 lb Fat Capacity, 120,000 BTU)

The Comstock-Castle CC-GDF30 is a floor-model gas doughnut fryer built around a stainless steel tube-style fry vat measuring 24 inches wide by 24 inches front-to-back. Where the SF-series countertop fryers in the Comstock-Castle line are sized for mid-volume bakeries and concessions, the CC-GDF30 is a true production unit: 170 pounds of frying shortening capacity, 120,000 BTU across four cast iron tube burners, and a 33-5/8 inch stainless steel work surface that lets one operator run doughnuts continuously through a long shift without bending or stooping. The tank geometry, the cold zone designed into the bottom of the vat, the side drain board that doubles as a night cover, and the thermopile pilot ignition all point at the same thing: a fryer engineered for a working doughnut shop that needs to produce hundreds of doughnuts per hour, day after day, with predictable oil life and minimal cleanup labor.

Comstock-Castle has built commercial fryers in Quincy, Illinois since 1838 and is America's oldest stove company. The CC-GDF30 is ETL design certified and ETL Sanitation (ANSI-NSF4) certified for commercial foodservice use.

Best Use Cases for the CC-GDF30 Floor Model Doughnut Fryer

This is the fryer for a dedicated doughnut shop, a bakery running doughnuts as a daily morning program, a multi-shop wholesale doughnut operation supplying grocery and coffee accounts, a high-traffic concession trailer or doughnut food truck with floor space for a full-size fryer, a college or hospital foodservice kitchen producing fresh doughnuts for cafeteria service, or any production bakery that needs to fry significantly more product per hour than a countertop flat-bottom fryer can sustain. The 170 pound fat capacity gives operators a deep enough oil reservoir to handle continuous batch loading without dramatic temperature drops, which is the single biggest factor in doughnut quality during a long service window. Cake doughnuts loaded into a 35-pound countertop fryer at the rate of two trays per minute will drag oil temperature down 15 to 25 degrees F per batch and recovery time stretches out as the shift goes on. The same load into a 170-pound CC-GDF30 produces a recovery curve measured in 8 to 12 degrees and the oil never falls below the working window, which is what produces doughnuts that look and taste the same at minute 5 of service as they do at minute 95.

How a Floor Model Doughnut Fryer Differs From a Countertop Flat Bottom

Countertop flat-bottom doughnut fryers are designed to sit on a 36-inch table and are sized for operations that need a doughnut option without committing dedicated floor space. The CC-GDF30 is the opposite design philosophy. The unit stands on its own 6-inch adjustable stainless steel legs, the work surface is built into the frame at 33-5/8 inches, the tank is significantly deeper from front to back (24 inches versus the 21 inches of the SF countertop tanks), and the frame is engineered to anchor a flue stack that reuses exhaust heat for combustion efficiency rather than just venting it. The result is a unit that is purpose-built for a doughnut production line: the operator stands in front of the unit, the proof box or doughnut depositor sits to one side, the draining or glazing station sits to the other side, and the doughnut workflow runs left-to-right or right-to-left through the operator's standing position. There is no countertop, no separate stand, no shimmying of a heavy fryer onto a worktop. The fryer is the workstation.

Tank Geometry and the 18 by 24 Inch Vat

The CC-GDF30 tank measures 24 inches wide by 24 inches front-to-back. That orientation is intentional: the operator faces the long axis of the tank, which gives the fryer two rows of doughnuts deep from front to back rather than a single wide row left-to-right. A standard cake doughnut measures about 3-1/4 inches across once expanded, which means the working surface of the tank holds approximately 7 doughnuts wide by 7 doughnuts deep, or about 49 doughnuts per pass at maximum density. Most operators run lower density than that, typically 28 to 36 doughnuts per pass, which gives the operator room to flip each doughnut with a wooden dowel without crowding. At 60 to 75 seconds per side, a single operator running the CC-GDF30 at standard density can produce 1,100 to 1,600 cake doughnuts per hour, which is the production rate that makes the unit economical for a dedicated doughnut shop.

The vat itself is stainless steel tube-type construction with a cold zone built into the bottom. The cold zone is the section of the tank below the burner tubes where oil temperature is lower than the cooking zone above. Sediment, glaze drippings, doughnut crumbs, and other particulate falls into the cold zone during frying and sits there at a lower temperature, which dramatically slows the rate at which that debris carbonizes and breaks down the oil. The result is longer oil life. Operators running a doughnut shop without a cold zone typically replace oil every 4 to 7 days at high volume. Operators running a fryer with a properly engineered cold zone typically push oil replacement to 10 to 14 days at the same volume, which is a real operating cost difference at 170 pounds of shortening per fill.

Burner System and Heat Delivery

The CC-GDF30 uses four cast iron tube burners, each rated at 30,000 BTU per hour for a total of 120,000 BTU. Tube burners are a different design from the H-pattern atmospheric burners used in the SF countertop series. The tube burners are positioned horizontally beneath the tank in a parallel arrangement and the flame impinges on tube-shaped heat exchangers that run through the lower portion of the oil. Heat transfers from the burners through the tube walls into the oil along the full length of each tube, which produces a more even temperature distribution across the 24-inch tank depth than a single bottom-fired burner could deliver. The cast iron burner bodies hold heat well, which smooths out the on-off cycling of the thermostat and reduces temperature swings during continuous frying.

Natural gas is the factory standard. Optimal supply pressure is 5 inches water column for natural gas, 10 inches water column for propane. A propane conversion kit is available for installations on LP. The gas inlet is a 1/2 inch rear connection and a 3/4 inch adapter is provided with the fryer for shops that prefer to land 3/4 inch gas line from the wall stub-out.

Snap Action Thermostat and Safety Controls

The 200 to 400 degree F snap-action thermostat is the same control logic as the SF countertop series. Snap-action means the thermostat is fully open or fully closed with no proportional middle ground. When the oil drops below the setpoint, the gas valve opens fully. When the oil reaches the setpoint, the gas valve closes fully. There is no modulation. For doughnut frying this is the preferred behavior because doughnut shops run at a single setpoint for long periods and the operator wants the burners to come back hard during recovery between batches.

The safety control package on the CC-GDF30 is more extensive than the SF countertop series. The fryer includes a combination safety valve and pressure regulator (a single integrated unit that handles both gas shutoff on flame failure and incoming pressure regulation), a double safety high-limit control (two independent over-temperature switches that will shut the fryer down if the primary thermostat fails and oil temperature climbs past the safe limit), and a thermopile pilot system. The thermopile is the small thermocouple-style sensor that sits in the pilot flame and generates a small electrical current as long as the pilot is lit. That current holds the main gas valve open. If the pilot ever goes out, the thermopile current drops, the main gas valve closes, and the fryer cannot deliver gas to the burners until the pilot is relit. This is the standard safety architecture for a standing-pilot commercial gas fryer and the CC-GDF30 implements it with a double redundancy on the high-limit side that exceeds the typical single-switch design.

Side Drain Board That Doubles as a Night Cover

The CC-GDF30 ships with a side drain board that mounts to the side of the frame and serves two functions. During service it sits beside the fryer at work-surface height and provides a place to set the wire lifting screen as doughnuts come out of the oil, so excess oil drains back toward the tank rather than puddling on the operator's work surface. At end of shift the same drain board lifts off its service mount and lays flat over the open tank as a night cover, which keeps dust, debris, and ambient kitchen contaminants out of the oil during the hours the fryer is cold. This is a meaningful detail because doughnut shops typically run their oil for 10 to 14 days and the single biggest source of oil degradation between shifts is contamination from open exposure to kitchen air. A proper night cover extends the working life of the oil and is one of the operating cost differences between a purpose-built doughnut fryer and a general-purpose fryer pressed into doughnut service.

Wire Lifting Screen and Doughnut Workflow

The CC-GDF30 includes a 24 inch by 23-5/8 inch wire lifting screen sized to the tank interior. This is the primary tool the operator uses to lift finished doughnuts out of the oil at the end of the second-side cook. The screen sits across the tank with the doughnuts arrayed on top and is lifted straight up with both hands, then walked to the drain board or the glazing station. Some operators run the screen as a flotation rack throughout the entire fry cycle, in which case the doughnuts are placed onto the screen at drop, the screen sits at oil level during the first-side cook, the operator flips each doughnut individually with a wooden dowel for the second-side cook, and the screen is then lifted out at finish. Other operators run the screen only as a lift tool at finish, in which case doughnuts are dropped directly into the oil from a depositor or hand, flipped individually, and only consolidated onto the screen at the end of the cook for the lift. Either workflow is valid and the CC-GDF30 supports both.

Flue Design and Exhaust Heat Reuse

The CC-GDF30 frame includes a special flue design that routes exhaust gases through a heat exchange path before they vent. The intent is to reuse some of the thermal energy in the exhaust stream to preheat the air going into the burner combustion zone or to add heat to the tank walls indirectly, which reduces the total BTU input required to maintain frying temperature at steady state. In practical operator terms this shows up as lower natural gas consumption per pound of oil heated and per doughnut produced compared to a fryer that simply vents combustion exhaust straight out the back. The flue design does not eliminate the requirement for a Type 1 hood (the CC-GDF30 is a commercial gas fryer producing grease-laden vapor and combustion byproducts and must be installed under a Type 1 commercial hood with UL 300 wet-chemical fire suppression in any indoor commercial kitchen) but it does reduce the operating gas cost.

Doughnut Frying Temperatures and Cook Times

Cake doughnuts typically cook 60 to 75 seconds per side at 370 degrees F. Raised yeast doughnuts typically cook 50 to 60 seconds per side at 360 to 365 degrees F. Crullers cook 45 to 60 seconds per side at 370 to 375 degrees F. Mini-doughnuts and doughnut holes cook 30 to 60 seconds total and are usually turned with the screen rather than flipped individually. Flipping is by feel: the operator watches for the bottom edge of each doughnut to turn from pale to deep golden, then rolls the doughnut over with the dowel. After the second side hits the same deep golden color, the doughnut is lifted out with the wire screen and laid on a draining rack or pan over absorbent paper.

Oil Selection and Tank Fill

The CC-GDF30 tank is filled to 170 pounds of frying shortening or oil at the marked oil level line. Most doughnut shops run solid all-purpose vegetable shortening that solidifies at room temperature, which is the traditional doughnut shop standard and produces the classic crisp exterior with a tender crumb interior. Liquid frying oils (high-oleic canola, sunflower, or palm-blend doughnut frying oils) are also commonly used and produce a slightly lighter texture. Whichever the operator chooses, the tank should be filled to the marked oil level line and topped off as oil is absorbed by the product during service. Cake doughnuts absorb 25 to 30 percent of their weight in oil during frying, raised doughnuts absorb 15 to 25 percent, and that absorbed oil needs to be replaced from the fresh-oil reservoir to keep the tank at fill level.

If running solid shortening, melt the shortening at low temperature setting before bringing oil up to frying temperature. Cold shortening on a hot burner can scorch on the tank bottom and develop off flavors. The standing pilot can be used to warm shortening slowly overnight in some installs, but most operators prefer to start the burner at low setting and ramp up over 20 to 30 minutes from solid shortening at the 170 pound fill level (a longer warmup than the SF countertop series because the larger oil mass takes proportionally longer to come to temperature).

Oil Management, Glaze Runoff, and Cleaning

Doughnut frying produces a different debris profile than french-fry or chicken frying. The main contaminants are flour dust from the doughnut surface, glaze drippings from finished doughnuts returned to the line, sugar particulate, and small dough fragments. The cold zone at the bottom of the tank captures most of this debris during service. End-of-day cleaning runs through the 1-1/4 inch grease drain valve and drainpipe extension on the front of the unit. The valve is sized larger than a standard fryer drain because doughnut shop shortening tends to be more viscous than thin liquid oils, particularly when cooling, and a 1-1/4 inch valve clears the tank in a reasonable time even with semi-solid shortening. The drainpipe extension threads onto the valve and directs oil into a shortening disposal container or a filtered transfer setup.

Boil-out cleaning every 7 to 14 days clears the cold zone debris that does not drain with the oil. Fill the tank to the marked oil line with water and commercial fryer boil-out detergent, bring to a simmer at low burner setting, and let it work the deposits loose for 20 to 30 minutes. Drain through the front valve. Rinse twice with clean water and drain. The stainless steel tank wipes down with a soft cloth and the cold zone is the only spot that typically needs additional scrubbing with a long-handled brush before the next oil fill.

Specifications

Model	Comstock-Castle CC-GDF30
Configuration	Floor model, natural gas, doughnut fryer
Frame Dimensions	29-1/2 inch W x 39-5/8 inch L x 51-1/8 inch H
Tank Dimensions	24 inch W x 24 inch L
Work Surface Height	33-5/8 inch
Fat Capacity	170 lb
Total BTU	120,000 BTU per hour (4 burners x 30,000 BTU each)
Burner Type	Cast iron tube burners
Thermostat	Snap-action, 200 to 400 degrees F
Safety Controls	Combination safety valve, pressure regulator, double safety high-limit control, thermopile pilot system
Drain	1-1/4 inch diameter grease drain valve with drainpipe extension
Gas Connection	1/2 inch rear connection with 3/4 inch adapter included
Gas Pressure	5 inches WC natural gas / 10 inches WC propane
Gas Type	Natural gas factory set, LP conversion kit available
Construction	Stainless steel front, galvanized side panels, stainless steel tube-type fry vat with cold zone
Flue	Special flue design reuses exhaust heat for combustion efficiency
Legs	6 inch adjustable stainless steel
Included Accessories	Side drain board that doubles as night cover, 24 inch x 23-5/8 inch wire lifting screen
Certifications	ETL design certified, ETL Sanitation (ANSI-NSF4) certified
Shipping Weight	325 lb

Download the full Comstock-Castle CC-GDF30 spec sheet (PDF)

Installation, Ventilation, and Code Requirements

The CC-GDF30 is a commercial gas fryer for indoor installation under a Type 1 commercial hood with UL 300 wet-chemical fire suppression. The hood capture area must extend at least 6 inches beyond the front, sides, and back of the fryer at the cooking surface, and the hood must be ducted to outside per local mechanical code. A K-class fire extinguisher must be mounted within the kitchen line of sight. The fryer requires a dedicated gas supply with a manual shutoff valve installed within reach. Maintain manufacturer clearance from combustible side and rear walls. Always verify combustible and non-combustible clearances against the installation manual and local code before final placement.

The 1/2 inch rear gas connection accepts the included 3/4 inch adapter if the shop's gas stub-out is sized at 3/4 inch. Confirm incoming gas pressure with a manometer at 5 inches water column for natural gas or 10 inches water column for propane before lighting the pilot. The 6 inch stainless steel legs are field-adjustable for leveling on uneven floors, and the fryer should be leveled with a long bubble level set across the rim of the tank in both directions before the oil fill so that oil depth is uniform across the entire 24 inch length of the vat.

Frequently Asked Questions

How does the CC-GDF30 compare to other Comstock-Castle doughnut fryers?

The CC-GDF30 sits in the middle of the Comstock-Castle floor-model doughnut fryer line. The smaller CC-GDF24 has an 18 x 24 inch tank, 125 lb fat capacity, three tube burners, and 90,000 BTU. The larger CC-GDF38 has a 34 x 24 inch tank, 220 lb fat capacity, five tube burners, and 150,000 BTU. The CC-GDF30 splits the difference at 24 x 24 inches, 170 lb fat capacity, four tube burners, and 120,000 BTU. The Comstock-Castle SF series (2923SF, 2932SF, 2941SF) are countertop flat-bottom fryers designed to sit on a 36-inch table for mid-volume bakeries and concessions. The CC-GDF30 is a true floor production unit with its own 6-inch legs, integrated 33-5/8 inch stainless steel work surface, tube vat with cold zone, and a more extensive safety control package than the countertop SF series.

How many doughnuts per hour can the CC-GDF30 produce?

Approximately 1,100 to 1,600 cake doughnuts per hour at standard batch density with a single experienced operator, running 60 to 75 seconds per side at 370 degrees F. Raised yeast doughnuts at slightly lower temperature and slightly shorter cook times can push production rates higher. Mini-doughnuts and doughnut holes loaded by depositor can exceed 2,000 pieces per hour because the smaller pieces cook faster and load denser.

What is the cold zone and why does it matter?

The cold zone is the lower section of the fry vat positioned below the heat input of the tube burners. Oil in the cold zone runs at lower temperature than the cooking zone above. Crumbs, glaze drippings, and other debris fall through the oil to the cold zone where the lower temperature slows the rate at which that debris carbonizes and breaks down the oil. Operators running a fryer with a properly engineered cold zone typically extend oil replacement intervals from 4 to 7 days up to 10 to 14 days at the same production volume.

Does the CC-GDF30 need a Type 1 hood?

Yes. The CC-GDF30 is a commercial gas fryer that produces grease-laden vapor and combustion byproducts and must be installed under a Type 1 commercial hood with UL 300 wet-chemical fire suppression in any indoor commercial kitchen.

What thermostat range does the CC-GDF30 cover?

200 to 400 degrees F snap-action thermostat control. The full range covers solid shortening melt at the low end (around 200 to 220 degrees F) through standard doughnut frying temperatures (360 to 375 degrees F) up to the upper safety limit at 400 degrees F.

Can the CC-GDF30 run on propane?

The CC-GDF30 ships factory-set for natural gas. An LP conversion kit is available for installations on propane. The kit changes the burner orifices and the regulator spring to the LP setpoints (10 inches water column versus the natural gas setpoint of 5 inches water column). Conversion should be performed by a qualified gas technician and verified with a manometer before the unit is placed in service.

What size gas connection does the CC-GDF30 need?

The fryer has a 1/2 inch rear gas connection and ships with a 3/4 inch adapter. Most shops with 3/4 inch gas stub-outs use the adapter for a direct landing. Confirm gas pressure at 5 inches water column for natural gas or 10 inches water column for propane before lighting the pilot.

How much fat does the tank hold?

170 pounds of frying shortening or oil at the marked fill line. That capacity is the working oil mass; the tank is sized to accept the fill plus the displacement of doughnuts during frying without overflow.

What is the work surface height?

33-5/8 inches from the floor to the top of the work surface. This is the ergonomic standard for a standing operator running doughnuts continuously through a long shift.

What is included in the box with the CC-GDF30?

The fryer, the side drain board that doubles as a night cover, and the 24 inch by 23-5/8 inch wire lifting screen. The 3/4 inch gas adapter is also included for shops that need to land a 3/4 inch gas line on the 1/2 inch rear connection.

Is the CC-GDF30 NSF and UL listed?

The CC-GDF30 is ETL design certified and ETL Sanitation (ANSI-NSF4) certified for commercial foodservice use. ETL Sanitation under the ANSI-NSF4 standard provides equivalent sanitation certification to direct NSF listing for the same standard. ETL design certification is the safety and performance equivalent of UL listing for commercial gas equipment.

What ignition system does the CC-GDF30 use?

A thermopile pilot system. The standing pilot generates a small electrical current through a thermopile while the pilot is lit, and that current holds the main gas valve open. If the pilot goes out, the thermopile current drops and the main gas valve closes automatically, preventing gas flow to the burners.

How often should I replace the oil in the CC-GDF30?

Most dedicated doughnut shops running the CC-GDF30 replace oil every 10 to 14 days at high volume. Replace when free fatty acid level exceeds 2.0 percent, when smoke point drops below 350 degrees F, or when oil color turns dark amber and the doughnuts start to taste like the oil rather than the dough.

How do I clean the cold zone?

Drain the oil through the 1-1/4 inch front grease valve at end of day or end of cycle. Fill the tank with water and commercial fryer boil-out detergent to the marked oil line, bring to a simmer at low burner setting, and let it work the deposits in the cold zone for 20 to 30 minutes. Drain. Rinse twice with clean water and drain. Scrub the cold zone with a long-handled brush if any residue remains before the next oil fill.

What is the side drain board for?

During service it mounts to the side of the frame at work-surface height and serves as a draining station for the wire lifting screen as doughnuts come out of the oil. At end of shift it lifts off the service mount and lays flat over the open tank as a night cover, which keeps dust, debris, and ambient kitchen contaminants out of the oil during the hours the fryer is cold.

Pricing and ordering?

Contact us for a price quote.