Let us start by addressing one of the biggest points of confusion in the world of coffee. Many individuals within the specialty coffee industry labor under the misconception that the freezing of roasted coffee beans will adversely affect the fats that are present, in a manner that is similar to the freezing of cream. This is completely false. The fats in cream have formed mycelium (microscopic globules) and are in colloidal suspension. If this colloidal suspension is challenged by freezing, the mycelium break apart and the suspension collapses. In contrast, coffee beans are solid and the fat is supported by solid cell structures, and no such collapse is possible. Freeze your coffee beans, but pay close attention to the following discussion.

The storage of your precious coffee is extremely important, and there is considerable confusion, at all levels, as to what the proper methods are. Not only did we spend three years researching this aspect of coffee at all levels in the specialty coffee industry, but we retained the services of a chemist, who specializes in the chemistry of coffee, to provide unequivocal direction in this area. The following rules will provide you with the guidance you need to protect the quality level of your coffee beans.

1. Don't let coffee beans come into contact with oxygen. Oxidation in coffee beans is the number one factor in causing coffee to go stale.
2. Don't let coffee beans come into contact with moisture, either in the liquid or vapor forms. Water vapor will condense when cooled down to form liquid water. Just remember that the water vapor contained in air at room temperature will condense into the liquid form when the air is cooled down to a certain temperature, referred to as the "dew point". The exact dew point depends on the amount of water vapor (relative humidity) contained in a given quantity of air at room temperature. Rest assured that your refrigerator, and certainly your freezer, will produce the condensation of water from room temperature air. Water greatly increases the oxidation within coffee beans, and the presence of water in coffee beans leaves them in a very unstable condition.
3. Don't let coffee beans come into contact with light. Aside from raising the temperature of the beans, light will dramatically increase the chemical activity on the surface of the beans.
4. Keep the temperature of the beans as low as possible. Lowering the temperature reduces the rate of all chemical activity in the beans. A popular misconception we've found is that people, both at the consumer level and the industrial level, believe that if all the oxygen and moisture are removed from the atmosphere surrounding coffee beans, the coffee will not go stale. Not true! There are chemical reactions going on inside coffee beans that do not require oxygen, and are referred to as "anaerobic". These anaerobic reactions can never be stopped, and will eventually destroy the quality of the coffee. They can, however be considerably slowed down by lowering the temperature. The lower the temperature the better. If you have opened a bag of coffee that was packed in nitrogen, the atmosphere will eliminate the protective benefits of the nitrogen. If you don't plan to use all of this coffee within a few days, you should repack the coffee in Zip Lock plastic bags. Each bag should contain the amount of coffee you consume in a few days. The plastic will prevent air and water from entering, but it will not prevent the loss of crucial flavor volatiles. If the coffee is going to be stored for a long period (such as weeks) you might consider wrapping each plastic bag with aluminum foil which is a perfect gas barrier. Coffee should not come directly into contact with aluminum because the acids in coffee will react with the aluminum.. The temperature in the freezer and your taste sensitivity will dictate if they can be successfully stored for a longer period of time. Six months is quite realistic.
5. Don't allow frozen, or cool coffee beans to come into contact with warm air, unless you plan to use all of the beans being exposed right away. Remember that warm air contains water vapor which will condense immediately on the cool surface of the beans. The condensed water will be rapidly absorbed into the beans. It is a good idea to take a packet of beans out of the freezer the night before you are going to open the packet.
6. Do not apply extreme heat to frozen beans or try to thaw them out in a microwave oven. Raising the temperature of the beans too high will restart many chemical reactions that will immediately destroy the quality of the coffee.
7. Never grind coffee beans until you are ready to brew. Ground coffee simply cannot be reasonably preserved in any way.
8. If you have purchased pre-ground coffee, all of the preceding principles apply, but be aware that the grinding process has destroyed one of the most significant preservation factors ... the physical structure of the whole bean itself. The coffee bean provides natural layers of paraffin and oil which significantly retard the loss of flavor volatiles and carbon dioxide (carbon dioxide prevents oxidation). These layers of protection also make it more difficult for oxygen to enter the bean. Once the physical structure of the bean has been broken down, the staling process jumps into high gear and races ahead of any known technology to control the degradation.

For a more technical discussion on the subject of freshness of coffee, click here.

The proper way to measure coffee is by weight. If you are really serious about coffee, then you should invest in a scale that can weigh small portions of coffee accurately. A good scale is indispensable when blending your own coffee in small amounts, unless you want to spend a lot of time counting coffee beans. You can measure coffee by volume, but you lose a lot of accuracy because of varying bean densities and having to rely on visual estimation. The proportion of ground coffee used in relation to the amount of water used, constitutes the brewing ratio. After the coffee has been brewed, the amount of solubles that have been extracted in relation to the amount of water, constitutes the drinking ratio. The brewing ratio usually determines the drinking ratio, but it doesn't have to. Hot water can be added to the infusion after brewing to reduce the concentration and flavor intensity of the brew, thus changing the drinking ratio. Experimentation will lead you to your own personal brewing and drinking ratios. It is always wiser to brew your coffee on the strong side and then "cut" it to taste with water. If coffee is brewed too weak, all you can do is start over. The Standard Brewing Ratio & Preparation Chart is based on industry accepted standards, but is intended to be a starting point only. The Connoisseur's Brewing Ratio Ration & Preparation Chart  gives the brewing ratios that are accepted as the standard by serious coffee drinkers. It can not be stressed enough how much personal taste should be the sole basis for determining brewing ratios. It is very easy to misjudge a coffee that has been prepared using a brewing ratio that is not suited to your individual taste.

• GRIND (PARTICLE) SIZE
  The purpose of grinding coffee beans is to enable the water to remove (extract) the solubles (flavor compounds, oils, and solids) that create the flavor and body in coffee. The grind, or particle size must be matched to the brewing method, and the particle size must be as consistent as possible. The particle size (aggregate size) is extremely important to successful brewing. Don't be mislead by the popular belief that a finer grind will give you more flavor. The finer you grind coffee, the more particle surface area in relation to particle mass is being exposed to the hot water. The finer the grind, the more rapid the extraction. Over-extraction means you get too much, both what you want and what you don't want! The aggregate size must be matched to the brewing method being used, and the brewing time must be correct. Using an "espresso grind" for a drip brewer will slow the flow of water through the aggregate, and would result in a badly over-extracted and bitter infusion. If the grind is too coarse, the water flows too rapidly, and the resulting infusion will be under extracted and watery. The grind size for the press method is larger than the flat drip / gold filter size, and you generally have to use twice as much aggregate as with the drip method. You'll have to experiment to determine how much sediment you can tolerate in your coffee. The grind size has to be increased to eliminate sediment. The goal is an 18% to 22% extraction rate from the coffee particles. We provide a Grind Size Calibration graphic to help you set your grinder for the correct grind.  To view or print this graphic, click here to go to graphic page.

TYPES OF GRINDERS

• BLADE
  Blade grinders are inexpensive but produce a very inconsistent particle size. Even if you're trying to get a course grind, you will get some powder. Blade grinders are nothing more than little blenders that slice, tear, and smash the coffee beans. Worse yet ... since the blades are spinning at a very high RPM, it is very easy to burn the coffee. Using a blade grinder to grind just enough beans for a single cup is an exercise in futility. You'll have to experiment with any particular blade grinder to achieve the desired results. As a rule, you don't want to grind for more than 20 seconds. Beyond 20 seconds you risk burning the ground coffee. If you are grinding a small amount of beans, say for one cup of coffee, you should shake the grinder as it is grinding. When grinding three ounces of beans the blade grinder will produce the best results, because the aggregate produces good resistance to the blades and a natural flowing circulation of the aggregate occurs. Never try to grind more coffee than is recommended by the manufacturer.
• BURR
  The old fashioned hand grinders are excellent devices, and they only cost a little more than blade grinders. They are burr grinders, and have not been significantly improved upon since they came into existence . They're slow (about a minute for one cup), but they produce a very consistent aggregate, and there is no chance of burning the coffee. They are still made today, and size of the grind can be adjusted from very course to powder. There are burr grinders that are powered by electric motors, which takes the effort out and is faster.
• DISC AND CONICAL
  Disc and conical grinders provide the most precise grinding. These grinders have serrations or grooves cut into the discs or cones. The coffee beans fall in between the two discs or cones, one of which turns while the other remains stationary. The sharp edges of the grooves are what cut the beans and result in the most consistent grind. These are the grinders of choice for high quality coffee, but they are quite expensive.

WARNING REGARDING THE GRINDING OF FLAVORED COFFEE
Never grind flavored coffee in the same burr, disc, or conical grinder that you use for straight coffee. The flavor extracts coat the grinding discs and are virtually impossible to remove. Flavor extracts in grinders will impart flavoring to straight coffee.  Blade grinders can be cleaned, but you will discover that removing the extract completely from the blades, and the grinding chamber, is not all that easy.

• WATER
  The water to be used must be right or the coffee will be wrong. The infusion you drink is mostly water. The flavor of coffee can easily be contaminated by other intruding influences. The best rule of thumb is, if the water you are going to use doesn't taste right, don't use it.  It should have no discernible taste, or "character", such as sharp or astringent qualities. Bad water makes bad coffee. As a rule, bottled spring water is your best bet. Municipal water is usually not good enough for high quality coffee, unless you are using a good filtration system. Water that has been "softened" should also be avoided.  It does not extract as well as non-softened water. Distilled water should not be used, because all of the mineral content has been removed. The minerals in water are essential to the extraction process.  It is very important to note that if you're using any type of container to store water in, it is very important to frequently, and thoroughly clean the container.  The build up of bacteria in water being used to brew coffee will have a dramatically negative effect on the coffee.  This is one of the most commonly overlooked sources of trouble when brewing coffee.
• WATER TEMPERATURE
  The brewing temperature of the water used is very important. It should be between 195 F (91 C) and 205 F (96 C). The closer to 205 F (96 C) the better. Boiling water (212 F - 100 C) should never be used, as it will burn the coffee. Water that is less than 195 F (91 C) will not extract properly. Keep in mind that if frozen beans have been ground, the aggregate will drop the temperature of the water upon contact. In this instance the temperature of the water being added to the aggregate should be right at 205 F (96 C).
• THE BREWING PROCESS ITSELF
  There are two basic brewing concepts you need to understand, percolation and maceration. Percolation means water is allowed to flow around the particles and through the aggregate of ground coffee. Maceration means the ground coffee is soaked (or steeped) in the water.
  
  Brewing a perfect cup of coffee is the weakest link in the full enjoyment of fine coffee. Buying the finest coffee is only the beginning and can go for naught if the brewing is not done correctly. It is very easy to ruin otherwise excellent coffee with improper brewing. We realize you would like to hear that once you have purchased excellent coffee beans, the rest is as simple as pushing a button, but, all we can say is: it's time to "wake up and smell the coffee". The grower, and the roaster do their parts, and you have to do your part. If either party drops the ball, exquisite coffee will not happen. The first thing that must be understood is what is going on during the brewing process. The aggregate (ground up coffee particles) is being exposed to hot water in order to "extract" the essential solubles (flavor compounds, solids, and oils) from the particles. That which is extracted winds up in the water, creating the infusion we call coffee. In theory, perfect extraction would get everything that's desirable out of the coffee bean and into the cup, while leaving behind all that which is undesirable. Is this possible? Currently, only in our imaginations. But some methods are better than others, and one comes pleasantly close.
  
  Understanding the extraction process will enable you to learn how to brew coffee successfully. First, the grind, or aggregate size, of the coffee is crucial. The finer the grind, the more surface in relation to mass is exposed to the hot water. An un-ground coffee bean results in the least amount of surface area in relation to mass, and would be impossible to brew successfully. The tendency is to assume that the more finely coffee is ground, the better the resulting infusion will be. This is where you can destroy a good cup of coffee. The trick is to get just what you want out of the coffee, and no more. If the grind is to fine, and the exposure too long, you'll get everything. Over-extraction of the aggregate will dissolve too many of the undesirable compounds, generally referred to as "bitters". If you shorten the extraction time, you'll fail to dissolve the essential flavor compounds that were so carefully developed during the roasting process. The challenge is to get the aggregate size and the extraction time in perfect balance. It is of the utmost importance that you understand that the brewing time must be controlled exactly. Improper brewing time is one of the main reasons that people get different results when preparing coffee.
• There is an important exception to "exact brewing time".  90 percent of the solubles are extracted during the initial phase of the brewing process.  It is possible to get to achieve your best results with a grind that's slightly on the fine side, and shortening the extraction time.  For instance, when I use our ground coffee in a French press, or the brew and filter method, I use a 3 minute extraction time.  Since our grinder is calibrated to grind coffee that will achieve a 4 minute extraction time in a commercial airpot brewer, for my taste, 4 minutes in the French press over-extracts with our ground coffee.  By the same token, you can also use more coffee than usual in a drip brewer with a short extraction time.  It's all a matter of increasing surface area, reducing extraction time, and getting less of the bitter compounds that take longer to dissolve.  It comes down to experimentation, and finding your perfect brewing formula..

• ESPRESSO COFFEE MAKERS
  The word espresso means three things. It describes the beverage or infusion, the blend to make espresso, and the method used to make espresso. It is the latter that we are concerned with. Don't confuse the method with the beverage. The espresso machine was originally invented to make coffee, not "espresso". The term espresso in reference to the beverage came into use later. To the Italians espresso is coffee. The espresso method of brewing is the ultimate method of extraction. It falls into the percolation category, with a twist. A very fine grind can be used, because the hot water is forced very rapidly around and through the aggregate under great pressure (about nine to ten times normal atmospheric pressure). The water actually being forced through the coffee particles is what puts the espresso method in the percolation category.  This results in the maximum amount of desirable solubles being extracted, but because the process is so fast, not all of the bitter compounds have time to dissolve. Less of the caffeine is dissolved, when compared to other brewing methods. What's really significant about the espresso method is that the hot water under pressure is able to emulsify about ten percent more of the oils (fats) in the aggregate than any other method. It is the oils that give coffee it's body and smoothness, and greatly enhance the flavor. The infusion produced by the espresso method is more viscous (thick) and has a lower surface tension. Lower surface tension enhances the ability of the liquid to coat the papilla where the taste buds are located, thereby enhancing your ability to sense flavor. The lower surface tension also enables the tiny oil droplets to penetrate the pores of the papilla and slowly release the aromatic substances that have bound to the oils. This accounts for the noticeable after taste of coffee brewed in an espresso machine. The additional oils also inhibit the sensory receptor cells from sensing bitterness. Don't be confused into the notion that espresso coffee is something different than regular coffee. Espresso coffee is regular coffee. The beans for traditional espresso coffee have been specially blended and roasted longer to produce a unique effect. Espresso coffee is brewed, and consumed at very concentrated brewing and drinking ratios. In short, by using the espresso method properly you get more of what you want and less of what you don't want, and that simply translates into the best coffee imaginable. The beauty of the espresso method is that once the proper grind has been determined, and the desired proportion of coffee to water has been determined, the rest is handled by the espresso maker. It is the simplest method, requires less time on your part, requires the least amount of cleanup effort, and produces perfect results every single time. In fact good automatic espresso makers are as easy as pushing one button.  Of course there is a hefty price to be paid for such convenience.  But, we think the price is well justified if you want the very best coffee.
  
  The key to understand in this method, is not to use too much water in the espresso maker. Let's say you wanted to make a cup of coffee that was equivalent to the standard brewing ratio rather than espresso strength. You would generally use 6.8 grams of coffee, and 1.25 fluid ounces of water to brew the coffee. It is very important that the correct balance of grind size and degree of tamping of the ground coffee is achieved. The water should be forced through the aggregate in 15 to 25 seconds. After the coffee is brewed, you add just under half a cup of water (3.9 fluid ounces) to the cup. If you ran all of the water through the ground coffee, you would severely over-extract the coffee, and it would not taste good at all. Automatic espresso coffee makers are the most convenient method of making coffee in existence, but there are important considerations to be aware of. Only the short coffee (espresso), or double short coffee (double espresso) options should be used. The regular coffee or tall (long) coffee options should not be used. They use the same portion of ground coffee as the short coffee, but force more water through the aggregate. This results in over-extraction. As mentioned before, you should add the necessary hot water after the extraction process. The other drawback to the automatic machines is that there is always a small amount of ground coffee left in the machine from the last cup that you make. This ground coffee will go stale in a matter of hours, and then will be included in the preparation of the first cup the next day. Unless your machine provides an effective way of purging all unwanted ground coffee, the first cup made should be disposed of. Convenience has yet another price.
• BREW & FILTER
  The brew and filter method is the classic coffee connoisseur's method of brewing coffee, and is in the maceration category. The beans are ground, placed in a container, hot water is added, and the container is covered. Allow the infusion to steep for about 3 to 4 minutes. It is best to steep closer to 3 minutes rather than 4 as it is very easy to over-extract using this method.  During the steeping process, stir the infusion at least three times, always replacing the cover. After steeping, the infusion is poured off into a cup through a nonabsorbent filter. The best filter choice currently is a gold filter. Under no circumstances should a paper filter be used. A paper filter will absorb some of the essential oils in the infusion, and since less oils have been emulsified with this method, as opposed to the espresso method, it's essential that you don't lose any of what you do get. This method, and all other methods, require a much longer exposure time than the espresso method, which means the aggregate must be coarser. If the coffee was ground as fine as it is for espresso, then too many of the undesirable compounds would be extracted, or if the exposure time were shortened, much of the desired compounds would not be extracted. The problem with the coarser grind is that, due to the larger particle size, the longer brewing time is necessary to extract the desirable compounds nearer the center of the particles. Obviously, the compounds near the surface of the particles get too much exposure to the hot water, allowing extraction of the undesirable compounds. A compromise must be struck, and this is done by trial and error to each individual's taste. Once you have determined your proper brewing time for any particular strain of coffee, stick with it. The brew and filter method is preferred by many people over the espresso method, because the sensation of taste is not as "heavy", and the acidity and "brighter notes" can be more apparent. You might choose the espresso method for some coffees and the brew and filter method for others.
• PLUNGER, FRENCH PRESS, OR EUROPEAN PRESS
  The plunger method (maceration category) is where the ground coffee is placed in a cylindrical container and hot water is added. A disc (with a rod attached in the center), which is same diameter as the cylinder, is placed over the water and ground coffee. The disc has many very small holes in it, or large hole covered by a fine mesh screen. There is a physical limit to how small these holes can be necessitating a fairly course grind. After about four minutes of steeping, the disc is pressed down through the infusion forcing the coffee grounds to the bottom, and allowing the infusion to be poured off.  This method produces excellent results, but you generally have to use twice as much ground coffee because the grind has to be so much coarser.  You can use a finer grind if you don't mind the resulting sediment n your cup.  When using a finer grind, it's best to use a total steeping time closer to 3 minutes, and press the disc down slowly, starting at about 2 and a half minutes of steeping.  With a finer grind, pour the coffee slowly, and leave a little in the press.  This will greatly reduce the sediment in your cup.
• DRIP
  The drip method is the least desirable of the acceptable methods, and falls into the percolation category. We are not, by any means, saying that you can't produce a thoroughly enjoyable cup of coffee using the drip method, but simply that it won't be as good as it can be. The drip brewer must be designed perfectly. The opening that allows the infusion through to the cup must be just the right size to keep the hot water in contact with the aggregate for the right amount of time, between 3 1/2 to 4 minutes. Over 4 minutes and you'll be over-extracting.  The longer it goes, the worse it gets. There are a number of problems inherent with the drip method. First, some of the water goes through quickly, resulting in under-extraction, and the infusion that drips through last is over-extracted. The drip method relies on gravity to move the water through the aggregate, thwarting optimal extraction. The other problem with drip brewers is that the extraction will vary depending on how much coffee you're making. If you're brewing a full pot, the higher level of water in the basket creates more head pressure causing the water to pass through more quickly, and the initial infusion is even less extracted than when you're brewing just one cup. Look at it this way -- If it takes longer to brew a pot of coffee than it does to brew one cup, then something has to be wrong. There is an optimal amount of time for aggregate to be exposed to the hot water, no matter what amount of coffee you're brewing. Cone filter designs do a better job than flat filter designs. If the design of the drip brewer does not allow for adjustment of the extraction time, then you're not going to be able to make good coffee, except for one amount.  If there is a drip brewer that provides a means for adjusting the extraction time, we would like to know about it!  An inferior drip brewer can ruin perfectly good coffee to the point that even an expert coffee taster couldn't identify the coffee. Optimal extraction time is precisely why coffee connoisseurs prefer the preceding methods. If you are going to consider a drip brewer, you should pay close attention to the extraction time, and stick with small capacity designs. Above all, make sure it employs a gold filter ... never a paper or fiber filter.  The drip method requires a lot of experimentation.  One of the most critical factors to keep in mind is that different coffees will produce different extraction rates.  The darker coffee is roasted, the longer the extraction time, all other factors being equal.  Decaf will really slow the passage of gravity drawn water.  The bottom line is that you have to make what ever adjustments are necessary for the coffee you're brewing in a drip brewer.  There is no simple solution.  Using our Grind Size Calibration Chart will provide a good starting point for determining how to grind your coffee.
• PERCOLATOR
  The percolator method deserves little attention, in light of the preceding discussion. Constantly recirculating boiling water through ground coffee will obviously result in Over-extraction. Simply don't use it.

• HOW TO BREW ICE COFFEE

You don't brew ice coffee by cooling down coffee that has been brewed normally.  During the cooling process there would be excessive loss of volatiles during the cooling process, unless you can cool the brewed coffee without exposing it to any air.

To brew ice coffee properly, the coffee is brewed using half the amount of water during the brewing process. The trick is to properly control the extraction time.  Remember, when you're using the drip method, you shooting for a four minute extraction time.  After brewing, or during brewing with the espresso and drip methods, the hot infusion is poured or dripped directly into a cup or container containing ice (crushed is preferable). The amount if ice should be what would be needed to produce the desired drinking ratio in the final infusion. When making the ice there are two things to remember. Use the proper water, and make sure the water is frozen in measured containers so that you can determine the final drinking ratio. Again, when in doubt, always brew coffee on the strong side and then cut with water, if necessary.

• HOW TO STORE BREWED COFFEE

The only way to store brewed coffee is in an air pot (vacuum thermos with a pump). The air pot should be "primed", that is, preheated with boiling water, or pre-cooled with ice or in a freezer.  If you are pre-cooling an air pot in a freezer, make certain to leave the top open.   As soon as the coffee has been brewed, it should be immediately put into the air pot. Never allow coffee to sit in an open container on a warming plate. Brewed coffee is losing volatiles to the atmosphere at a tremendous rate, and will begin to significantly lose flavor within minutes.

Fine coffee should not be consumed the way you would normally drink a more common liquid, such as water. Simply drinking the coffee and swallowing it deprives you of much of flavor it has to offer. Coffee should be aspirated or sucked into the mouth, the way you would consume it if it were far to hot to drink quickly. In terms of the coffee industry lexicon this is referred to as "slurping". As the coffee is aspirated into the mouth, the coffee is partially atomized into tiny droplets and sprayed into the mouth, releasing far more of the flavor volatiles. The coffee should not be swallowed immediately, but held in the mouth and swished about before being swallowed. This enables all of the sensory nerve endings in the mouth, primarily on the tongue, to be fully exposed to the many chemical compounds that we have gone to so much trouble to produce during our meticulous roasting process. We appreciate that Emily Post would have us prosecuted for suggesting this method of enjoying coffee, but etiquette and proper Epicurean appreciation don't always follow the same path.

• DRINKING TEMPERATURE

High quality coffee should be 140 F (60 C) and no more than 160 F (71 C) when consumed. Hotter coffee will diminish the ability of the taste receptor cells to sense properly. The sensory capacity decreases rapidly with the rise in temperature of the infusion. One of the main reasons Americans have developed the habit of drinking coffee so hot is the poor quality of coffee that has been sold in the past. Hot coffee can't be tasted very well, and if the coffee doesn't taste good to start with, the solution is obvious. How common it has been in the past to hear someone complain that their coffee has cooled down and that it tastes horrible. They were right! Now that the specialty coffee industry is bringing much higher quality coffee to the masses, cooler drinking temperatures become crucial.

• Air Quality

This is one of the least known, and can be the most elusive factors affecting the taste of coffee.  There will be times when everything about the coffee, the water, and the preparation are perfect ... yet the taste is somewhat off, or downright awful.  The culprit may well be something in the air.  In our own facility, we can not drink our own coffee when we are grinding coffee for packaging, or when we are flavoring coffee.  At these times, the concentration of aromatic compounds in the air dramatically affects the taste of the coffee.  While it may seem strange that the gases released by grinding coffee, will have a negative effect on the taste of brewed coffee, I can assure you that the effect can be quite dramatic.

So, you might ask: what airborne substances are on the list to avoid?  Unfortunately, we can't possibly know all of the various substances that might be problematical.  The best guide is: if there is a noticeable odor in the air, and the coffee doesn't taste right, try to establish a connection, or lack of, between the order and the taste of the coffee.  Keep in mind that once you have been exposed to "guilty" airborne substances for a period of time, that they are absorbed into the linings of your breathing passages, and will continue to affect your sense of taste for a time after your are no longer directly in contact with the odor.