Cold brew coffee takes time, patience, and most importantly, the perfect grind. MPE designed the industrial-grade GPX and GPC-140 coffee grinders to meet the demands of small batch cold brew makers looking to brew the best quality product.
The precision disc-style GPX and GPC-140 grinders are designed for capacities of 200 – 1,000lbs/hr and run continuously without diminished grind accuracy. The GPX uses 5.5 inch diameter “diamond hard” grinding discs that are precision-cut to optimize cutting action with infinite adjustment control, resulting in a cool, uniform coffee grind for optimal brew performance. The GPC uses larger 7.1 inch diameter discs for greater volume.
Consistent grind is critical when steeping for long periods of time, and can influence the quality of the coffee you serve. Ensuring grind uniformity, in combination with cold brew steeping methods will ultimately deliver the smooth, round taste identified in a truly well-made cold brew beverage.
Good coffee capsule and pod production requires more than just roasting, grinding, and packing coffee into pods and capsules. It also requires an extra step to make sure the density of the ground coffee is optimal for capsule and pod brewing. To understand how density works and its role, we must look at the following:
The coffee particles’ shapes when they exit the grinder and how to optimize their shapes for greater density
The use of water pressure in capsule and pod coffee makers and how density is a factor to increase extraction
Coffee’s shape when it leaves the grinder
Coffee particles are not smooth and spherical when they exit the grinder. They are jagged and non-spherical, which means they tend to fill the capsule inefficiently. With less coffee in each capsule, the results are a weak and under-extracted cup of coffee.
Using a process called densification, the coffee particles are literally rounded out, sometimes even having many smaller fines clustering together into larger sized particles. On a microscopic scale this means considerably more total dissolvable solids can fit into the same amount of space.
The role of water pressure, and density as a factor
Densification is not a new concept. Tamping an espresso is basically a form of densification. It not only serves to fit more coffee (and dissolvable solids) into the portafilter, but also provides the resistance needed for the hot water to forcefully extract the crema and volatiles in such a short brew time.
Like espresso machines, capsule and pod coffee makers also use pressure to extract the coffee’s flavor and volatiles. Densified coffee in pods and capsules provides an optimal amount of resistance for the pressurized water to extract the dissolvable solids of the grounds.
The result is the consumer enjoys a better cup of coffee.
After coffee is ground by the top section, it takes on a static charge, which, along with the help of the coffee oils, causes it to stick on the inside surfaces of the roll chamber. Gravity is what makes the coffee fall into the subsequent rolls, however not consistently—at least not without the help of the Black Ice Deflectors.
Without these deflectors, coffee accumulates like snowpacks on the internal surfaces and then falls like an avalanche. These avalanches are hard spikes of resistance detrimental to rolls, components, and motors. The sheering function of the rolls suffers when the rush of coffee forces its way between the rolls leading to crushing, which is not good for achieving accurate particle size distributions. Some manufacturers answer the problem by having chains inside each chamber that slide across angled deflectors. But this is a purely mechanical approach not favored by MPE because while chains manage the problem, they do not solve it. Coffee particles still accumulate like snowpacks waiting for the next chain sweep, merely dividing up the avalanche into many smaller ones.
How MPE’s Superior Approach Solves the Problem
The approach favored by MPE is a two-fold solution. First, a vibration device behind each panel renders the entire surface unstable and virtually impossible to stick to. Secondly, application of a food-grade non-stick Black Ice coating on the deflectors helps transient particles in their downward slide into lower chambers. This two-prong approach achieves a consistent rate of coffee always falling into subsequent rolls to eliminate torque spikes and achieve the most accurate particle size distributions.
Granulizer rolls, journals, and bearings are designed for precision grinding in large volumes. With applications requiring tight particle distributions and roll gaps as small as 50 microns, stabilizing tolerances and controlling temperature can make all the difference between a great coffee product and an inferior one.
Heat alters tolerances and contributes to faster mechanical wear. Heat on just a single bearing can throw off the parallelity of the rolls and significantly alter particle distributions and reduce overall precision.
To control the heat of the components, one of MPE’s signature engineering designs is genuine thru-water cooled rolls found on most IMD models. The idea is simple; running water through both sets of bearings and journals—and rolls of course—so that they stay a consistent temperature during operation. This two-sided coolingkeeps the rolls in perfect parallel operation and reduces component wear.
Water-cooling design seen on competitors’ industrial coffee grinders are usually one-sided. And while this may adequately cool the rolls and prevent an undesired 2nd roast of the coffee, non-cooled bearings on the other side are liable to increased heat-related wear and metallurgical expansion leading to a loss of roll parallelity. This loss results in a less precise grind, and consequently, a lower quality ground coffee product.
Chain-Vey’s rotating discharge tube is designed around the needs of our customers. The unit can open and close while the conveyor is running—no stopping and starting required. It won’t break any product either as its rotating tube gently glides around the chain and pucks that pass through. For potentially sticky applications, a compressed air nozzle inside the unit sprays the chain and pucks to ensure complete product removal.
MPE’s Rotating Discharge Tube is Clean-In-Place-ready for all system types; from hybrid to full-CIP. Models range for all Chain-Vey diameters from 3″ to 6″.
Petfood Forum in Kansas City, MO is a great place for pet food manufacturers to see Chain-Vey in person. It’s also an opportunity to talk with our engineers, discuss project demands, and learn about other projects and ideas. Chain-Vey will be there with a 4″ diameter fully operational model to showcase its gas-tight, hassle-free, and automated clean-in-place design. Engineers Andrew Willse and John Eiting will be there to meet everyone who stops by.
Chain-Vey’s location at Petfood Forum 2017 is booth 473.
For over 60 years, MPE has built the finest array of commercial and industrial coffee grinders in the world. This year is no exception in the level of innovation MPE brings to the industry. The IMD.2 800 Series grinder makes its worldwide debut at Interpack 2017; the first of its kind to implement independent drive motors for each roll. Users can electronically customize each roll’s speed to achieve a range of ratios from 1:1 to 1:4. The IMD.2 800 Series’ automated recipe-driven control system with precision servo gap control allows for micro fine adjustments in 10-micron increments. This heightened precision in gap control coupled with individually adjustable roller speeds is beneficial for espresso pod and capsule applications; effectively engineering a perfect, repeatable grind. Genuine thru-roller water-cooling ensures a continuous flow of cool water through all rolls and bearings, keeping them cool. This stabilizes tolerances and ensures perfect parallel operation—even during periods of extended operation. MPE will also bring its 3” Chain-Vey system, built for unsurpassed preservation of coffee aromatics during conveyance. Its gas-tight design and nitrogen-purge capabilities are great for Turkish coffee, pod, and capsule makers. For an up-close demonstration at Interpack 2017 visit booth A04 in Hall 2.
The MPE booth at Global Specialty Coffee Expo 2017 will feature the GPX.WCI and SRM 4555 coffee grinders along with MPE’s 3” Chain-Vey system. The versatile water-cooled GPX.WCI stands beautifully with its stainless steel hopper and black, blue, and polished steel exterior. Capable of grinding between 50 microns (ultrafine) to as large as 1000 microns (coarse filter), it is the staple of many startup roasters. The more robust SRM 4555 grinder is the perfect fit for those making their first foray into the world of accurate, higher-capacity roller-style grinding. MPE’s booth number at the Global Specialty Coffee Expo is 1010.
MPE announces the Gemini Series Model IMD 779.2 Coffee Capsule Granulizer with variable roll speed ratios for achieving the strongest particle size distribution for coffee pods, pads, and capsules. The Gemini has Independent Motor Drives for each roll, allowing customizable roll speed ratios ranging from 1:1 to 1:4 to yield particle size distribution differentials engineered for each application. Its automated recipe-driven control system provides the repeatability of all parameters and grind characteristics. The Gemini is the pinnacle of precision capsule grinding equipment and ultimate grind control.
Caribou Coffee, the well known Minnesota-based coffee chain, installed cable tube conveyors in their roastery several years ago. Their first cable system transported green coffee from an unloading point to their classification equipment. The cable conveyor manufacturer had promised longevity. However roastery managers became largely dissatisfied upon experiencing a much higher cost of ownership and maintenance than promised over time.
Green coffee is typically abrasive and for this reason wears conveyors more quickly than other applications. Roastery managers were replacing cable and pucks on a 18 to 24 month basis due to cable stretching. Cable fraying also meant having to splice sections of cable periodically. Plus, if the cable broke in the middle of production, managers did not want to splice cable with orders unfulfilled. They wanted to try a Chain-Vey system and see if it truly meant less maintenance and greater reliability.
MPE engineers offered a cost effective Cable-to-Chain-Vey retrofit for their green coffee cable conveyor. It would capture nearly all of the benefits of Chain-Vey without needing to replace the entire conveyor. It could also be done in half the time it takes to install a new conveyor.
The retrofit installation was a breeze and completed in half a day. Roastery managers were impressed on the first production run by reduced noise coming from the conveyor. As time went on though, the most important benefit has been the peace of mind in the system’s reliability. The chain will never fray and never break.
“Never have to worry about it. It’s quieter than the cable system. Pretty much a set it and go piece of equipment.”