1950s THE POPCORN SHOP
Description: 1948 MINIT POP, 1950s U-POP-IT, 1950s THE POPCORN SHOP, 1950s PopMatiCorn, Early 1960s POP-O-MATIC. These coin operated popcorn machines from the mid 1940s to the mid 1950s provide not only great entertainment while popping an individual portion of popcorn, but fantastic, movie-theatre-quality tasting popcorn in just 1 minute. More info on other pop corn machines can be found here.
A more familiar looking cabinet style is seen in US Pat. Nos. 2,657,627 and 2,639,961, both filed in late 1947.
In late 1950, as explained in US Pat. No. 2,742,848, the design of the cooking element was changed from a STRAINER BASKET to a HOT PLATE design. As explained in that patent filing:
Where a bath of cooking oil is retained in the popping chamber between popping periods and maintained at or above the breakdown temperature, the breakdown of the oil is increased and an undesirable gum deposit is rapidly formed in the container defining the popping chamber, usually adjacent the liquid level therein. This gum deposit hardens and must be periodically cleaned by a special chemical cleaning operation. As the deposit builds up, the operating parts tend to bind against each other, hindering the mechanical operation, as well as leaving the machine in an unsightly unsanitary condition.
Truth be told, both cooking systems have their advantages and disadvantages. For instance, the strainer basket is unencumbered by electronics or oil supplies, so it can be somewhat frequently removed easily by taking out the 4 acorn bolts and dropped in the dishwasher. The patent confirms that the intent was easy removal for cleaning. This is not an option with the later hot plate basket, which includes heating elements, thermostats, and a hose connection to the oil supply. Thus, it must be cleaned in place.
According to the patents, the cycle time of the STRAINER BASKET design was 75 seconds (including 60 seconds for popping). The HOT PLATE design increased that time to 95 seconds. While this distinction is rather insubstantial, particularly for home use, the amount of oil absorbed by the corn is significantly different between the designs. According to the patents, the STRAINER BASKET design uses 3/4 ounce of oil per cycle, while the HOT PLATE design uses twice as much, 1 1/2 ounces of oil per cycle. That might be an important distinction for the calorie conscious.
Over the years, manufacturing rights for the popcorn machine passed through a number of companies. The first manufacturer, in 1948, was The Viking Tool & Machine Corp. of Belleville, NJ, who called the machine MINIT POP. Rights to manufacture the machine were apparently sold to a company in Minneapolis, MN in the late 1940s, who changed the name to U-POP-IT. Sometime after that, it appears to have been sold again to another company in Minneapolis, MN, who changed the name yet again to THE POPCORN SHOP. It appears that this wasn’t the end of the road for the popcorn machine design, as the author has seen a more modern styled cabinet probably from the late 1950s or early 1960s bearing the unmistakable mechanics of the U-POP-IT type apparatus, red popcorn supply cup and all, this time called POP-O-MATIC and manufactured by a company called VENDOTRONICS of Lynbrook, N.J. This late style machine packed much more functionality (e.g., salt packet dispenser, butter applicator, automatic bag dispenser) into a thinner cabinet, but most notably at the great expense of aesthetic appeal.
For all models except the late style POP-O-MATIC, the model name and manufacturer are printed on a metal name plate that’s riveted to the popcorn chute. Most name plates have a triangular shape to them, though U-POP-IT name plates appear to have had a period in which they were square.
Perhaps the most popular restoration color scheme is RED with a YELLOW door. Pinstriping, painted instructions on outside of cabinet, etc., are for the most part not original. However, much of what this author has seen in restored machines is quite pleasing, expressive of the particular restorer, and generally adds to the character and enjoyment of the machine today and beyond.
Original cabinet colors:
Cabinets restored to original colors:
OIL VAT / STRAINER BASKET:
A wiring diagram for the STRAINER BASKET design is found in US Pat No 2,657,627, reproduced below:
The hot plate design is a little more messy than the strainer basket design, though not if properly adjusted. In the hot plate system, any oil that isn’t absorbed by the popcorn pours into a catch basin below the basket, and drips down a waste pipe into an appropriate container. In the strainer basket design oil drains very quickly back through the screened bottom as the basket is lifted from the oil.
The 3/16" of oil in the OIL VAT variety machines is kept at the cooking temperature of 395 degrees while the machine is on, allowing the corn to pop in 1 minute. In the HOT PLATE variety machines, an initial squirt of oil is maintained on top of the hot plate at a standby 350 degrees, purportedly below the breakdown temperature of the cooking oil (at least with respect to coconut oil as used in the 1940s). This means that for most home collectors, you must turn the popcorn machine on about 20-30 minutes before you intend to use it to allow the cooking oil to reach the desired temperature.
Both systems work fine. The heating coil element for the oil vat system is relatively simple to restring and replace, and readily available from any good appliance supply store. The hot plate, on the other hand, is a custom item that has been reproduced, though it may become harder to find in the future.
One way to detect a hot plate system from the front of the machine (with the door open) is if you see an oil drain pipe pointing down at 45 degrees from the oil vat toward the right side as you look at the machine. From the back, the OIL VAT strainer system has a float valve just behind the cooking basket, whereas the hot plate has an electrical connection directly into the back of the cooking basket.
Note the oil drain pipe:
It has been said that hot plate machines are probably found equally as many as OIL VAT types, though there might be a slight favoritism to finding an OIL VAT type. It is believed that the HOT PLATE types might have had a higher rate of failure, leading to a higher percentage of discarded machines of that type. More likely though is that HOT PLATE machines were made for more years, and more recently, than were OIL VAT type machines.
Of note is that there is also an immersion heater in the oil supply vat to keep the oil supply at 100 degrees. Otherwise the coconut oil supply would congeal (unless you use straight Wesson oil, corn oil, or similar). But coconut oil gives the best taste and aroma (especially with the fan in the lid vent pushing the aroma out to passersby!)
The oil supply vat in all machines has a capacity of about 2 gallons. The oil supply vat should be kept at least 1/2 full of oil, which is about 1 gallon. If you have an oil vat cooking system with the popcorn strainer basket, the oil reservoir (which includes a float valve) has a capacity of about an additional 1 quart. One gallon of cooking oil will make about 200 bags of popcorn.
OTHER DIFFERENCES between models:
CLEAR WINDOW IN KERNEL VAT:
The clear window, in the opinion of this author, adds significantly to the interest of the interior during operation of the machine. If your MINIT POP does not have a window in the kernel vat, it can be cut rather easily with a dremel tool, and a clear plastic window riveted in, just as it was in later models of the machine.
INTEGRATED GARGAGE CAN:
It is somewhat agreed by many collectors that the garbage can is not aesthetically pleasing to the design and physically gets in the way somewhat, so it is not a terribly missed component if not present. If your U-POP-IT does happen to include the garbage can, for ethical reasons you might want to keep it with the machine but not have it displayed. To this end, the author notes that apparently the garbage can be reversed so that it protrudes INSIDE the bottom of the cabinet.
3-LIGHT FLASHING BAR:
From a restored machine, and from a brochure for THE POPCORN SHOP:
INSTRUCTIONS ON BACK DOOR:
WHEN LIGHTS FLASH
Sometimes these instructions are lettered directly onto the back door, other times it’s seen as a plaque attached to the back door. One collector’s original machine included a white opaque marquee with instructions mounted over the 3-flashing light bar, covering the lights, but allowing the three different colors of the lights to indirectly fill the interior.
Many, if not most, MINIT POPs didn’t have instructions on the back door (or the 3-light flashing bar), making for a more bland appearance. Many collectors opt to add a reproduction 3-light flashing bar and instructions on the back door. While perhaps not original to that particular machine, the instructions add to the décor, and the flashing lights make for a tremendous upgrade to the interior.
Front and rear view of overflow tray:
FRONT GLASS DECALS:
An original, early decal, from a MINIT POP:
A reproduction MINIT POP decal, probably later than the one above, (on a restored U-POP-IT machine):
Decals were used heavily in the late style POP-O-MATIC:
Early MINIT POP header:
The same header above, but lit up:
Backside of header above:
Some MINIT POPs exhaust fans:
and the ever-functional POP-O-MATIC exhaust fan:
Photo credits to: W.Bollman, M.Carter, W.Alexander, J.Newell, R.Berk, C.Harrell.
If you have a MINIT POP, U-POP-IT, PopMatiCorn or POPCORN SHOP machine for sale, whole or parts, restored or unrestored, please contact me at firstname.lastname@example.org
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