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Showing posts with label Freshly Roasted Coffee. Show all posts
Showing posts with label Freshly Roasted Coffee. Show all posts

Friday, 21 September 2018

Extending Freshly Roasted Coffee Lifespan

The main enemies of Freshly Roasted Coffee are Time, Oxygen, and Moisture.

A solution has been presented to the public that is more beneficial to the manufacturers than to the end user.

Background info:

Immediately after roasting the coffee beans begin to emit carbon dioxide in sufficient volume and pressure to burst a hermetically sealed bag.  Some roasters opted to degas the beans for one to three days to alleviate this problem while manufacturers came up with a new product, the valve.
http://nxt-roasters.blogspot.com/2011/12/do-coffee-bag-valves-leak-1.html
http://nxt-roasters.blogspot.com/2012/05/revisited.html

Valve Limitation - as currently used:

It is possible that the valve is a single solution to burst bags when with a little more thought it could have also help to extend the freshness of coffee beans.

The CO2 is roughly 50% denser than the air we breathe, which consists of about 21% Oxygen.  This means when packaged, on the first day, beans emit CO2 that gas drops to the lowest level in the container and pushes the existing air upwards.  Surrounded the Freshly Roasted Coffee Beans with CO2 retards the oxidation process, hence, slows down the staling process.  How well and for how long the freshness is preserved is much more difficult to assess and beyond the limits of a one page blog entry.  For arguments sake I say it gives an extra week.  This process exists for the beans that are continually bathed in CO2 which is not the case when there is a venting valve.  As shown in the photo the CO2 will rise up to the valve then exit rather than flush out the air above the valve.  That means that, as the photo illustrates, that only 2/3 of the beans are in CO2 providing the bag is not tilted.  If the bag was laid on it back so that the valve was at the high point of the bag then there would be a different outcome but bags are not stored, shipped, or displayed laying down.  That scenario would be improved by moving the valve upwards to minimize the amount of air in the bag.

Using a valve does allow the roaster to degas in the heat sealed bag which offers the consumers the security and assurance that the bag contents have not been tampered with.

Alternatives:

The NXT solution to this dilemma is to use a ziplock bag which presents more flexible packaging options.  First, all the oxygenated air is pushed out of the bag when the bag is kept upright.  We recommend that people scoop out the beans for immediate consumption rather than pour them out which would drain much of the CO2.  Leaving CO2 to protect the beans extends the freshness.  Our bags are in a supervised area and they are not opened after closing but for added security, where bags are placed in a public area and a heat seal is required a simple pin prick between the ziplock and the heat seal which will prevent bursting the bag and allow a flushing of the oxygenated air.

NXT advocates degassing in the bag to take advantage of the emitted CO2 to extend the freshness of the coffee beans.

We have a Carbon Dioxide high pressure tank and a regulator to test the effect of giving a shot of CO2 to a bag of beans that are more than a day old when outgassing has mostly ceased.

It might mean some beans will be destroyed with water to determine the volume of the interstitial spaces which will indicate how much CO2 has to be injected to bathe all the beans in a protective gas.

To Do:

Test to determine how CO2 will enhance the life of ground coffee.

Saturday, 1 September 2018

Freshly Roasted Coffee & Solubles

It is accepted that Freshly Roasted Coffee Beans are essential to a great coffee experience.

This is a preliminary exploration of two brewing methods; modified Turkish and espresso.  The hypothesis is that it is possible to increase the G forces on the brew for accelerated sedimentation of the coffee fines.  The accumulation of solids in the bottom would support the idea that it is possible to quantify the coffee strength for various brewing methods.  For now, it is assumed that the amount of solubles is directly related to the strength of the coffee.

At the top is a modified Turkish brew without the addition of Cardamon and Cinnamon.  Essentially it is coffee made with a very fine grind which remains in the cup.  Of course if the drinker insists on consuming the proverbial last drop he/she will also have a 10 g breakfast.  For this comparison the water to coffee ground ratio of 10:1 was used.  The brew decanted for approximately 2 minutes before 14 ml were removed and placed into the vial or tube.


 The espresso was made with 15 g of coffee which was pulled in 29 seconds to yield two ounces or 60 ml.  Again, 14 ml was transferred to a tube for further processing or accelerated decantation.

The espresso grind is tamped in the porta-filter which only allows smaller particles to pass through with the water.

The fine grind, brew in a cup on the other hand is initially separated by gravity alone.  Since it is not filtered it is possible that the larger grounds are decanted in the first 2 minutes.  The larger the grind the longer it takes to decant but since this is an extra fine grind it is possible that the 2 minutes was sufficient to decant even the largest particles.  Smaller particles may be held in suspension in the liquid whether by turbulence, Brownian forces, or magic.

Both brews were initially opaque when held in front of a light.
The results above are open to interpretation until further experiments are done.  All three vials show signs of sedimentation but the Turkish Grind had significantly more grinds in the bottom.  It may be possible to conclude that the particles were larger than those in the espresso.  The increased transparency does support the premise that the previous opaqueness was due to the larger particles.

The espresso remained largely unchanged.  It is difficult to establish with precision that .25 ml of fines were decanted.  The opaqueness of the processed espresso does support the idea that extremely fine particles are held in suspension.

The experiment did not support the hoped for conclusion where the amount of solubles could be measured and even categorized.  It appears that a greater G force will be required to compare drip coffee, to say, a brew done in a French Press.  Or to compare the brew of large chains to that of a K cup.

Hopefully, another iteration of this test will allow the measurement of a solubles so that  brewing can be optimized.  Without measurement it is difficult to optimize so many variables.

Now, a cup of coffee is needed to start the process.





Sunday, 8 July 2018

NXT Coffee Roaster Design not "off the shelf"

To Google Maps
Most coffee roasters are heated by  a natural gas flame.  Natural gas is a cheaper form of energy than electricity but it comes with inherent limitations.  Since the flame requires a continual supply of oxygen it requires a lot of air which must be raised from ambient to combustion temperature, this  is not the end of the energy waste.  The coffee roasting is usually done in the exhaust gasses of the flame which, are not hot enough after passing through the Roasting Chamber, to break down the roasting smoke.  That smell is similar to burnt toast, in the later stages, - imagine several kilo grams of burnt toast.  Hence, an Afterburner is required to raise the temperature to over a 1000°F to break down the smoke.  The large amount of air required by the flame means that a large amount of air must be raised from ambient temperature to over 1000°F.  Consequently, the Afterburner burns, depending on the model,  three times as much energy as the roaster (the equivalence of 6 home furnaces) just so that the neighbourhood will not see nor smell the roaster emissions.  Of course the emissions from such burners are always present but the operators hope that they become sufficiently diluted by the outside air that they will not trigger calls to the environmental agency.  Pollution awareness is upon us and some areas already require permits for coffee roasters with 5 kg or more capacity.

Are there alternatives?
There is, if the fabricator begins with a clean design slate rather than use off the shelf technologies.  First, the amount of air needs to be reduced to greatly reduce the waste of energy.  It is true that often the electricity is generated by the combustion of natural gas but the electrical companies have specialized equipment to remove and neutralize gas volatiles that individual roasters do not use.  Nevertheless, the electrical Roastaire™'s biggest advantage is virtually eliminating the continual feeding of air to the roasting process.  It is possible to recirculate the air with electrical heating because you do not need to feed a flame.  The advantage, is that less energy is required to heat the returning air than to heat room temperature air (ambient) to roasting temperatures.  There is less air to treat when neutralizing the emissions therefore it can be done on a continual basis. A minor advantage is that the oily smoke, as part of the re-circulation process, is burnt which helps to heat the roaster.

Does the design work?
 Below is a photo of the tubing that guides the re-circulated air to the Roasting Chamber.  The roaster was in service for 5 years before this photo was taken.  It had roasted about 30 tonnes of coffee.  It does illustrate why Fresh Cup Roastery Café (Saanichton & Vancouver) clients refer to it as  "Clean Air Roasting"

5 yrs of roasting = clean air duct





 Now compare the above photo with one taken of a drum roaster after one year of service.




There wasn't a copyright on the photo but I am not attributing the photo because there is little benefit to kicking a hornet's nest.

In 2010, it is reported that there were 1800 chimney fires, in the USA, that were attributed to coffee roasters.  What heating method do you think was responsible for this incredible statistic?












                                                ------------------------------------------
In the Roastaire the exhaust is passed through a second SmokEater© before it is discharged.  It roasted hundreds of batches inside the Toronto and Vancouver convention centres without the use of a vent or chimney.

What is exhausted?
 Only the air cooling the roasted coffee is exhausted after scrubbing it twice.  More details about the design reasoning will be forthcoming when the topic of Bean Cooling is approached.  In the interim here is some more information on an earlier NXT    blogspot page.




Friday, 15 June 2018

Question and Challenge What you Read

Company Blogs which very often are prone to being commercials should not be taken at face value or believed without reflection and sometimes, some research.  

One blogger (Blogger B) submitted a comment to a competitor " I read with interest your article entitled “Roasting with Hot Air: Benefits of Air Roasters” in your company’s newsletter."  He then proceeds to authoritatively expound on his own lack of knowledge in the roasting process.  The complication here is that the article, by Blogger A, he refers to has some rather glaring falsehoods i.e. "During the roasting process, the green coffee beans go through two major “pops” or “cracks” The first occurs when the internal temperature of the bean reaches approximately 356 degrees fahrenheit.".  The problem here is that no matter how long you boil water the temperature remains no higher than 212°F or 100°C.  The evaporative process greatly slows the bean from continually increasing in temperature until virtually all the moisture is evaporated.

It appears that Blogger B then proceeds to confuse degrees Fahrenheit with degrees Centigrade.  Blogger A writes "This hot air reaches temperatures of between 450 and 485 degrees fahrenheit" (232°C to 251°C) which is slightly above the 195°C to 205°C where the beans undergo an exothermic reaction.  A much lower temperature would essentially bake the beans.  Despite Blogger B's assertion that the air roaster is way too hot it is 100°C to 200°C less hot than a typical gas fired drum roaster.  It is true that the air roaster has a faster roast cycle but 4 minutes is absurd while 11 minutes is quite normal because the heat is quite evenly applied to all sides of the bean as they are churned in the fluidized bead.  Drum roasters only have fans which are incapable of pushing the air through the batch of beans therefore they only heat the top layer, the beans touching the drum, and beans that are falling off the rotating blades.  Blogger B's comments "Regardless of how heat is applied to the outside of the beans, heat reaches the insides of the beans by conduction. And, when it comes to heat conduction, coffee beans are not very good at it. Therefore the development of the insides of the beans always trails the development of the outsides of the beans."  Ironically he is presenting a case that favours the lower temperature of the air roaster (for the same reason you do not fry eggs on high settings).  This, however, is not true for the entire roasting session.  The heat moves inwards in the endothermic phase until the bean enters the exothermic phase.  

Think of lighting a damp piece of paper.  There is a reason why you can boil water, on a flame, inside a paper bag.  It is because the water seeping through the material prevents the paper from reaching its combustion point.  However remove that water, the paper will dry, and will then burst into flames.

Blogger B apparently does not realize that a full roast includes the exothermic phase where the heat is generated inside the bean.  See sectioned bean photo.  At this point the roasting process has to be monitored closely to "kill the roast" at the right time.  We prefer to cool within the Roasting Chamber because it is quicker and easily repeatable.  At this stage the transformation is very rapid therefore it is challenging to guess "the kill point" half a minute to a minute in advance because it takes that long to dump the beans never mind cool them.

Blogger B also comments on the single pass air roaster even though his system not only is a single pass air supply but it is roasting with the exhaust of the flame.  Imagine cooking supper with the car exhaust (maybe a propane powered vehicle is slightly more appropriate", it will certainly contribute all kinds of flavour.  Recirculating hot air cannot be done with a gas fired roaster because it starves the flame.  We do it in an electric roaster but it took five years to develop a blower that would survive the temperature.   Re-circulation improves the efficiency and makes it possible to significantly cut emissions.  

A gas fired Afterburner burns on average 3 times more gas than the roaster.  It decreases the visible smoke but really loads the exhaust with volatile organic compounds known as pollution.

Sunday, 15 April 2018

NXT Freshly Roasted Coffee vs Marketing Spin

There are a lot of excuses that are generated by the untimely delivery of coffee.  It appears that more effort is made to make up a fanciful story than to deliver freshly roasted coffee.

It is easier to examine process where companies will pronounce certain rules as if they were laws rather than an opinion or marketing ploy.  Grocery stores have convinced the government agencies that coffee is not a perishable or that its shelf life is greater than 18 months.  Why?  I would say that it fits in with their warehousing distribution model rather than their concern for delivering a fresh product.  The economy brand coffee purveyors notably dance around their weakness which is usually centered on freshness.  Most often there is a clash of goals between their purchasing based on price and their desire to sell at a high end price.  Obviously that is not the message they wish to convey so this is where the marketing dance is conjured.
The question "Is your coffee freshly roasted"?  The typical answers:
- we grind it just before brewing
- we brew on the hour
- we serve our coffee when it is at its prime
- our coffee is ground to a different level
- we have a special relationship with our roaster even if it is 500 miles away
- our roaster uses the best beans
In all cases the question is not answered because it is important to circumvent that limitation by presenting a subjective answer (usually missing the point of the question).  It is a chink in their armour that appears to only be visible to those who are passionate about coffee, inquisitive about the claims, and discriminating purchasers.

On that note, a client must judge if coffee beans must degas for one to 5 days.  The beans will degas regardless because the pressure is sufficient to burst a tightly sealed plastic bag.  I prefer to package ASAP after roasting, letting the beans degas in the bag.  To that end we keep the bags closed, but not sealed, and upright so that the carbon dioxide* (which is more dense and heavier than air) will displace the air by pushing it our the top of the bag.  The client is able to decide when to drink the freshly roasted coffee. We have not found a need for valves.  If the valve is kept as the highest point of the bag the interstitial spaces will also be occupied by carbon dioxide instead of oxygen rich air.

Unfortunately most valves are located around the mid-line which means only half of the bag is purged of oxygen.  To purge the air from the valve equipped bag the bag has to be laid down so that the valve is the highest point in the bag.  Emptying the bag requires the same consideration to preserve the CO2 level, while keeping the bag upright scoop out the beans rather than pouring out the beans along with the CO2.  Pouring the entire bag into the grinder will pour in the CO2 as well but I suspect that the CO2 will drain out the bottom of the hopper, through the burrs, and out of the grinder.  That illustrates a grinder limitation which should be examined in another post.

*  Carbon dioxide is a colorless gas with a density about 60% higher than that of dry air. Carbon dioxide consists of a carbon atom double bonded to two oxygen atoms.  Dry ice is the solid version of CO2.  The wafted vapour that we see above the dry ice exposed to room air is actually moisture from the air that has condensed due to the low temperature near the dry ice.

Friday, 27 March 2015

NXT Generation III Roaster

 
NXTRoasters Inc. is introducing its third generation advanced roasting system, which protects the purchaser’s investment, consumes the lowest possible energy, and exceed strictest air pollution standards Training time to roast is finished in days instead of months!  Its two-step roasted coffee bean cooling system provides outstanding repeatability of roast degree.

The System combines in a single unit:
  • A roasting and a heating chamber,
  • A chaff catcher,
  • Two afterburners,
  • Pneumatic conveyor to load green beans into roasting chamber, and transfer roasted beans to the packaging hopper

The NXT roaster is practically maintenance free, with threat of fire nonexistent!  Chaff from the air stream is separated prior air entering the heating chamber.  Roaster develops no tar deposits.


Specifications:

Batch capacity: 3 kg (green beans)
14.4 kg/Hr (roasted coffee beans)

Motor horsepower:
Main blower:                         2.2 kW
Pneumatic conveyor:             1.5 kW

Temperatures: Adjustable
Roasting: 235°C – 265°C

Heating:
Main heater:                           10 kW
Smoke Eater:                         1.5 kW  
Power consumption:      6.0 kW / Hr.
Including Built-in Afterburners!

Cycle Times: 8 – 12 minutes

Dimensions: 50” x 36” x 80

Sunday, 1 June 2014

Improving a Working Device

The picture links were removed because Photobucket decided to change the terms of usage in mid stream, so to say,  It is inconvenient for viewers but it is better to rid yourself of such people as soon as possible.  It is the attitude as much as the action.   We will try to repair that mess at NXTroasters.com

Unlike a painting a machine can be tuned to new requirements without changing its fundamental reason of being.

An interesting book A Culture of Improvement: Technology and the Western Millennium written by Robert Friedel in 2007, reviews the invention and evolution of many technologies.  He certainly highlights that many factors determine the course of an idea and that it is not always the best idea that dominates.  In school,  history classes often gave the impression that there were technological leaps whereas this informed text demonstrates that more often than not inventors or the mechanically inclined stood on the shoulders of others, so to say.  Often people that leaped too far did not succeed for various reasons; people did not accept such a change, existing materials did not have the required properties, incompatibility  with existing technology, competitors sidetracked "message" etc.  In essence many aspects of a development have to be "done right" to assure success.

It is baffling that the author chooses to dismiss the work of Tesla while he lauds laboratory managers who were often credited with the inventions of employees.  Design of the distribution infrastructure of alternating current is only stated not credited.  Marconi's patent applications were turned down for years because of Tesla's existing patents.  His patent was only granted when well connected wealthy business people employed their power to influence.  It is not too different to where a federal government  concluded that the tomato is a vegetable that is subject to import regulations.
Meanwhile back in the present the challenge is to find an acceptable balance between the best technology and the price of implementing the solution.  To improve the efficiency and greatly reduce pollution the roasting air is recirculated after purging it of nearly all the smoke.  Sounds simple enough but the reality of working in a hostile environment is challenging.  

Fluidizing the bed of coffee beans is essential to the proper mixing and even distribution of heat.  In the upgrade shown on the right the Blower bearings have a lubrication system to improve the Mean Time Before Failure which usually happened too soon at roasting temperatures.

The continual cleaning of the recirculated air means that the roaster does not emit smoke during the hot weather roasting process.  A distinction is made regarding the weather because when it is cooler steam is vented during the bean cooling process.  Such a roaster can be used in higher density areas thanks to the built in pollution controls.

Of course the great smell of coffee is not to be wasted therefore we vent the air used to cool the coffee beans straight to the street to act as an olfactory business sign.



Tuesday, 26 November 2013

Improving the Roasting Efficiency.

There are several aspects to be considered before a process can be implemented to improve a design.   Often it is possible to identify, let's say for the sake of discussion, 10 variables that will affect the process.  What is usually impossible to predict is the rank or the level of dominance of each variable unless you are really really really a gifted analyzer or clairvoyant.  Personally I resort to testing a few variables at a time to better understand their effect.  There will undoubtedly be surprises and inconsistencies when various variables are tested together but it is simpler to test in parts than in whole.

The testing results are unlikely to produce a clear graph such are joys of solving problems with multiple unknowns.  The results will give a better idea about the trade-offs that are required before a process can be adopted.  We maintained that coffee beans should be uniformly heated so that the chemical reactions that occur within the beans progress evenly.  It was also deemed important that the beans not be thermally overloaded.  To clarify; the bean has a certain capacity to transmit heat to its interior, if the heat applied is greater than what can be evenly distributed the exterior surface becomes much hotter  and creates a risk of scorching.  It is also for this reason that we roast at a relatively lower temperatures of 240°C to 250°C instead of ...  In "Espresso Coffee" R. Eggers writes the typical gas temperature of a drum roaster is 400° - 550°C.  The high temperature cooking analogy for beans hit by the super hot air is frying eggs while using the stoves highest heat setting.  Yet this fluidized bed roaster has a cycle time of less than 12 minutes versus up to 20 minutes in a drum roaster.   That  is Better Efficiency! 

The even distribution of heat is critical to preparing the beans for the roasting process.  We force heated air between the beans so that they are all heated, not just the outside layer.  There are small domestic roasters that also use air to create a fountain of beans.  It is quite dramatic but if the air flows through a narrow passageway then the remaining beans are not being heated until they gradually make it to the fountain.  Consequently, if you are looking for a home roaster look for one that pushes the air through all the beans.  Typically, the batch will move upwards as the beans are levitated by the flowing air then the air will break through and mix the beans.  The release of air pressure allows them to drop within the chamber but are then suspended again.  The air cushion has the added advantage of keeping the beans off the hot metal which often causes tipping which appear as little pieces of the exterior wall that leave behind a shallow cavity.

It is a simple concept that is regulated by many variables which turn it into a complex process.  

There is more to the efficiency quest than even thermal transfer and the recycling of air mentioned in the previous blog which leaves something to write about later.  Now it is time for an espresso.

Monday, 21 October 2013

Improving Roasting Technology

The picture links were removed because Photobucket decided to change the terms of usage in mid stream, so to say,  It is inconvenient for viewers but it is better to rid yourself of such people as soon as possible.  It is the attitude as much as the action.   We will try to repair that mess at NXTroasters.com

 The conventional approach appears to be - buy a roaster and endure its limitations.  Most conventional roaster owners spend more time developing marketing spin than improving their coffee roaster.   The deficiencies i.e. emissions are already the focus of some legislative bodies which require permits for roasters in their jurisdictions.   Oil burning engines, showing that blue smoke, are rarely seen on the road today yet many owners are complacent about roasting without pollution controls.

The roaster owners who are concerned that large plumes of smoke coming from their chimney are bad for their community image have purchased large gas fired after-burners that burn approximately three times more gas than the roaster itself.  Imagine if automobile pollution controls involved using three times more gasoline than the engine.

Rather than maintain the polluting status quo which may or may not have visible smoke, NXT Roasters Inc., have developed an alternative (branded the Roastaire in Canada) approach that uses the smoke generated as a source of roasting heat rather than expend large amounts of additional energy to thermally neutralize the smoke.   Both 15 Kg/hour concepts thermally treat the pollutants but one system uses a 400,000 to 700,000 BTU after-burner  to accomplish the task.

The first picture is of the main air passageway of a Roastaire after five years of full time roasting.  This revealing photo demonstrates the reason for their motto of "Clean Air Roasting".  This illustrates how efficient and effective the air is scrubbed clean as it is re-circulated during the roasting process.   This closed loop roasting process means that the air only has to be heated 20° to 40°C to return it to the roasting temperature.  Compare that to a single pass air supply that is continually heated from ambient temperature then sent to the chimney.   In "Espresso Coffee" R. Eggers writes the typical gas temperature of a drum roaster is 400° - 550°C.   What a wasteful process.




In comparison,
one drum roasters Maintenance Manual draws attention to the chimney,  "Even if residue build-ups do not exceed 1/8 inch (.3 cm) per year, clean system annually ".    The quotation is not properly cited nor acknowledged but I will do so if the manufacturer requests it.

They also have this picture of a drum roaster fan as a warning about the residue that coats some of their components.  Roast Magazine had the following quotation "It's not IF you're going to have a roaster fire, but WHEN."  Which roaster do you think requires the most maintenance?  Which type of roaster do you think was responsible for nearly 1,800 chimney fires in the USA in 2010?



Which roaster do you think roasted hundreds of pounds of green beans inside the exhibition hall of the last four annual 
Canadian Coffee & Tea Shows?

Wednesday, 31 July 2013

NXT Roasters has the Aeropress brewer

There are several brewing options available to the consumer but only a few have a "freshly roasted" priority mostly because they cannot deliver their coffee in a timely manner.

We searched  the Internet and wrote many emails to source the brewer that would give the best value to our customers.  The Aeropress is a well designed and built device which does not require an expensive electric brewer.

There are countless videos that address brewing with the Aeropress but most of them are not worth a mention because they exhort what I consider a faux pas i.e.
- advocating coffee is ok up to 40 days after roasting
- coffee should be used within 10 days of grinding
- a presenter attempts to explain how they defy the laws of physics by building unbelievable pressure
- another has concluded that the pressure pushing out the coffee is a vacuum
- for some reason some equate hot water with bitterness rather than improper roasting and staleness
Critical thinking is required on the Internet.  Yes, even now!

The Aeropress is versatile and has well designed accessories.  It can be used in two ways which are best explained by way of videos followed by pictures and explanations.

The KPCC Radio video demonstrates the Filter Down Method (photo to the left).  The temperature is important, it affects the extraction and should be above 90°C  (194°F).  The low temperature advocates probably make or sell machines that are unable to serve hot water.  The simplicity of the electric kettle is not to be scoffed at.  In an anecdotal observation a few tablespoons of coffee are placed on the bottom of your sink (especially appropriate experiment for those that have weeks old coffee but want to move to freshly roasted delights).  Allow some warm water to flow gently against the mini mound (gently - don't power wash it away) then increase the temperature.  You will find that the hot water dissolves while warm water agglomerates.

The Atomic Way video demonstrates the Inverted Method (photo below) which eliminates the dripping into the cup while mixing.



THE GRIND.  We often drink a modified Turkish style coffee where all the ingredients are mixed in the cup.  The finely ground coffee is only produced by a burr style grinder.  A finely ground coffee has a large surface area proportional to its volume which means a rapid extraction and that the grains soak up the water and decant quickly.  A fine grind like this creates a mini disaster in the gravity drained brewers because the water is poured onto the grind faster than the permeability allows it to go through, resulting in the dreaded overflow.  The plunger pressure in the Aeropress appears to circumvent that problem and yields a better extraction.

The end user has to determine the grind by experimentation.   A coarse grind will under extract and the water will be pushed through too quickly.



The Aeropress is then flipped over and placed
on a cup and the process continues as in the
conventional method.





FRESHNESS IS #1  The staling process starts after
roasting and begins to be detected at the end of one week.  Grinding the coffee accelerates the staling process.  The high surface area proportional to the content of a coffee ground means that it is more rapidly affected by oxygen and moisture.  Grind at the last minute.

More will follow shortly when the pictures of the various Aeropress components are taken or downloaded.

Tuesday, 28 May 2013

When Price is #1 Criteria ! (Who really pays ?)

A Purchaser is able to impose a price importance by choosing what is purchased based uniquely on the monetary cost.  Sellers quickly realize when a low selling price is required to make the sales.  Typically, "quality" is sacrificed to reduce the sellers cost while meeting a few important criteria such as appearance to a non critical eye.

Coffee beans do not visually change when way past their prime apart from having a little more surface oil.   That creates an opportunity for marketing spin that is analogous to a magic act.  The Purchaser may decide the price but the Seller decides everything else including the message that is crafted to give the Purchaser assurance that they received a premium product even when it is not.  In a magic show the spectator's attention is skillfully guided to the advantage of the magician so that the impossible is viewed as real.   The spectator does not suspend disbelief because they know that it is a performance.  Most spectators try to figure out how the magic was carried out.  For some reason low price marketing is not often subjected to the same analysis.

Economies of scale, low quality, and a magic presentation are fundamental to selling many products at low prices.  Foods with low or no nutritional value outsell fresh organic vegetables and are designed for the supply chain rather than the consumer.  The buying criteria are satisfied while other possible benefits are only implied.

Economy of scale can only be achieved with a wide network that can store and distribute a uniform product.  The supply chain optimized product, usually produced in one highly automated factory, to specifications that favour longevity or visual aspects .  The processing or transformation technology is optimized to fulfill the goals of the seller based on the buying criteria of the clients.  A great deal of research is undertaken to understand the buying decision and what common "markers" are used in reaching that decision.

The volume of imported roasted coffee is staggering.  This "Warehouse Coffee" does not reach the client while fresh but it does reach the end user while it is cheap.

My mantra is "Buy from a small batch roaster".   I prefer the freshest coffee over the exotic varietal that was roasted two or more weeks ago.

Sunday, 21 April 2013

Updating our Roastery




We updated our Roastery and reception area so that it would not be confused with the workshop.



It is slightly more pleasant to sit down at a Granite table for the morning Espresso than a work bench.  Well, there is the optional bar height table for the devotees of the fitness club.

The main goal is to show that our roaster does not require a lot of room.   There is a full glass door that encourages observation though a full glass wall would yield a better view of the Roasting Theatre.





The coffee roaster is the focal point and the "raison d'être".  The green beans are loaded into the counter height Bean Loader Hopper.  the design of which expresses our opinion about overhead bean loading.  After roasting the beans are pneumatically conveyed to the Packaging area which saves the Roast Master from picking up roasted coffee from the floor area.  It appears that drum roaster designers just do not think of ergonomics and Roast Master comfort. These are important considerations when the Roast Master does sessions of over 20 roasts.

The previous post has some pictures of some of our morning Espresso shots.  Not all shots are photographed since pictures are secondary to tasting.  That series of pictures were intended to illustrate the Crema obtained with Freshly Roasted coffee.

The Coffee Roaster is labelled "Roastaire" which is the distributor for NXT Roasters in Canada.  Check out their site for information about roasting, energy conversion efficiency, and roasting pollution controls.








Sunday, 24 March 2013

Maturing Espresso


The Espresso Transformation

Few people see the Espresso when it is all Crema.  You could be tricked into believing that it is an "air head".        Perhaps the roasting method deserves consideration but for now let's say that Freshly Roasted Coffee is the key which of course has to be supported by a well adjusted Espresso Machine.  This topic was also mentioned in a previous post.   The evolution is followed more closely this time. 
The first picture was taken 26 seconds into the extraction which continued for another two seconds.  The coffee is Cocamu (COCAMU is a coffee growers cooperative located in the district of Kirehe in the eastern province of Rwanda) roasted three days earlier.  The picture to the left was taken at the 4 second mark (after extraction).
 The Crema transforms into the liquid elixir.  The glorious description often depends on how badly the observer requires that first coffee.  The third photo, taken at the 11 second mark, is an indicator of the Crema to liquid conversion.  Unfortunately the graduated glass has rather coarse markings but they can be overcome by overlaying a grid on a printed picture.

 

Photo #4 is from the 20 second mark.  This is about when the client first sees the "magic potion".  Some may opine that a blend with a healthy Sumatran representation would be more appropriate.  That may be but it is outside the scope of this post.
 Photo #5, taken at the 34 second mark, is reasonably close to the typical serving time unless you yanked it out of the hands of the Barista which would only gain you three seconds and a frown. 
When are you served your Espresso?