NOTE: As mentioned in the introduction, some of the above steps may not be necessary for all users. For example, if you have a grinder that creates a very even, clumpless grind, you will not need to tap the portafilter to settle the grounds nor will you need to use the WDT.

Verifying That You Used the Correct Dose, and How to Adjust the Dose.
      Is the amount of coffee in the portafilter correct? Let's find out:

      Too much coffee will cause the shower screen or the retaining screw to damage the integrity of the compacted coffee. The puck will be damaged before the water begins to flow with the resulting channeling of the flow of water through the coffee taking the path of least resistance. The result is espresso with thin body and thin crema. The espresso will flow like water from the spouts instead of like warm honey. If the procedure above indicates that you have used too much coffee, try this:

      Using too little coffee and the flow may start slowly and thickly, but will turn blond and thin in as little as five or ten seconds. There is a narrow range as to what works best. As you become more adept at making espresso you will be able to adjust the dose to match your equipment, your coffee, and your taste.

      Using more is easy to achieve. Just add more coffee. But if you find you have been using too much coffee, it can be tricky to remedy. Some grinders create a very fluffy grind, and so you might find that a swipe across the top of the basket with a straight edge works best. Other grinders create a dense grind and you may need to swipe deeper.

      So, depending on your espresso machine's shower head, the basket depth, how deep the portafilter fits into the brewhead, your grinder, and the coffee and grind you are using, you may need to make adjustments to your dose. You may not need to do this at all if you have a grinder that has an accurate timer that grinds exactly the right amount every time. How do you know if it is the right amount? I recommend doing the "Lock and Remove" test on a regular basis to be sure that you are staying on track.

Fine Tuning The Dose
      The above procedures for dosing will get you pretty close to what works for most machines, but not all. Additionally, the better you get at controlling the other variables discussed in this article, the more important precise dosing becomes. Some machines come with deep baskets and using the directions above could easily result in using too much coffee. Others have shallow baskets and these require a precise dose for best results. So what to do?

      The next step for precision dosing is to use a gram scale to weigh the dose. There are a number of ways to do this, and you will have to figure out which works best for you. If you have a grinder that does not retain coffee in the chamber or chute you can weigh the beans before grinding. If not, then you might want to weigh the coffee after grinding.

      First, of course, you need to get a scale. Small digital scales made for weighing precious metals and gemstones work well. Be sure that the scale you choose shows a resolution of .1 grams. I just counted out 100 roasted coffee beans and got a mass of 11.2 grams, or an average of one bean weighing about 0.112 grams. This is an average and will vary depending on the coffee you use. Based on that, in a 16 gram dose you will find approximately 143 beans. Just five beans, one way or the other, can make a difference of over half of a gram, and that can be 3.5% difference in the mass of the dose.

      Weighing coffee to that precise of a mass might seem a bit, well, anal, but it adds a consistency that can be very important. With quality espresso machines that allow control of water temperature and have well designed water-pressure delivery and distribution, a precise dose can make an easily-discerned difference on the palate. I found 15 grams was OK, 15.5 to be a bit too much, and that 15.25 worked very well and produced a superior cup when I first wrote this article. Now, with a different grinder and machine I am using about 16.1 grams. Talk to me tomorrow when I might try 15.8 grams to see what happens. Will it make better espresso? I won't know until I try it. Without a scale achieving the control necessary to find out it would be difficult if not impossible you know what works best.

      How the amount of coffee is distributed in the filter basket is very important. Dosing the coffee and distributing it in the basket coincide and intermingle. Even if you have the correct mass of coffee, if it is a mountain in the middle or there is more coffee on one side of the basket than the other, the flow of water will be uneven it may actually disrupt the puck causing channeling once again.

      The first step in avoiding this is to dispense the coffee into the basket carefully. I like grinders with dosers because the barista can operate the dosing lever at the rate which matches the way they work. A doserless grinder will send the coffee forth at the rate determined by the size of the burrs, the grind setting, and the motor's speed. An additional benefit of using the doser lever is that it can be clicked rapidly while the grinder is working, dispensing small amounts of coffee as it falls from the grinder's throat, and that action tends to break up clumps before they can be deposited into the portafilter. The coffee falls like a drizzling rain and not a hail storm. How effective that is depends to some extent on the grinder you choose.

      I grind per shot. I repeatedly thwack away at the lever so that small amounts of coffee are ejected from the grinder into the basket with each click. All the while I am moving the portafilter around to get the coffee distributed as evenly as possible. Although it is difficult to achieve, the goal is to have the coffee evenly distributed and level across the top. Realistically, just try to get as close to that as you can. Beyond that, try to develop a procedure that you can repeat every time.

      Does your grinder create clumps? Some grinders are clump-free and others not so much. Some factors such as the humidity, static in the grinder, moisture level in the coffee, grind, chute design, materials used in construction of the grinder, etc., can combine to create extreme clumping. If your grinder creates clumps then you may need to use the Weiss Distribution Technique (WDT). After filling the portafilter with ground coffee, use a sewing needle, thin straightened paper clip, dissecting needle or other similar tool to stir the coffee in the portafilter.

      As shown in this illustration, I find that using a pattern of intersecting circles as you go around the basket to be effective. When accomplished with attention, this procedure will also assist in leveling out the distribution of coffee as well as breaking up any clumps. The added benefit of this procedure is that it tends to fluff up the coffee. You may find that, after WDT'ing you may be able to simply level off across the top of the portafilter and that will create a good dose mass. This will be apparent when you tamp. Remember that all these procedures are interdependent, so after changing the way you distribute you may have to change the dose or grind.

      Regardless as to whether you swiped across the portafilter, weighed the coffee, used the WDT, or any combination of procedures to dispense, dose, and distributing the coffee, it is possible that the coffee is not the same density throughout the basket yet. Distribution can be easily improved now by striking the entire portafilter downwards on the counter top. As mentioned previously, this should be done gently. Two or three light taps from an inch or two above the counter is sufficient. This give the coffee a chance to settle and level out before the tamping procedure which comes next. I use a tamping mat which not only protects my counter top but also absorbs a bit of energy making it easier to be gentle. A scrap of dimensional oak works as well. After this downward tapping you should find the coffee level. If not, it means that you did not dose or distribute the coffee evenly. Dump it back into the doser (or into a suitable container if you have a doserless grinder) and begin again. Never run ground coffee through a coffee grinder!

      Tamping the coffee helps assure that the coffee puck is the same density throughout and affords an even resistance to the flow of water. Water takes the path of least resistance, and if there is an area of lesser coffee density, the 130 PSI (9 BAR) of water pressure will find that area quickly and channeling will be the result.

      The choice of tamper is important. The most important decision is to get one that properly fits the basket you use. It should be as close of a fit as possible without binding. Some say that it's shape (the shape of the tamping face) should match the shower screen, and there are convex and concave shapes from which to choose. I used an inexpensive, one-piece aluminum, flat tamper for many these years and it worked fine. Feel free to experiment, but flat is a good way to go if you are not sure. There are also tampers with etched or engraved, parallel lines around the outer edges of the base. This shows not only that your tamper is being held straight in the basket but also is a quick way to verify the depth to which you are tamping which is an indication of consistent dose.

      There are so many theories concerning tamping that you could ask ten baristas and get eleven answers. Here is some information that will help you find what works best for you:

Tamping Force
      Once you have a chosen a tamper the amount of force to use when applying it to the coffee is the next decision. I have heard stories from folks who use just only slightly more the weight of the tamper to those who recommend a "handstand" tamp where you tamp as hard as you can. Recent testing seems to indicate that anything between about 15 pounds to about 55 pounds will yield about the same results. This is why you often hear a tamp force of 35 pounds being recommended— it is right in the middle between 15 and 55 (Although lower force tamps are often used with manual lever machines). More recently, 30 pounds of force has been widely recommended—this is midway between 10 and 50 pounds— still in that same range with a wide margin of error. Even if you deviate five or ten pounds it will have little effect on the outcome. You can feel this for yourself. As you increase tamping force you will feel the coffee stop compressing. Of course, this takes for granted that the other factors, notably dose and distribution, are correct.

If you find that you have to use a very low tamping force (under 10 pounds) check for any or all of these:

If you find that you have to use a very high tamping force (55 pounds or more) check for:

      If you are unsure what amount of force you are using I suggest getting out a scale. The bottom line is that, within reason, it doesn't matter much— at least to say, of the factors over which you have direct control, tamping force probably has the smallest affect on the espresso. If you find that a specific tamp is required, particularly one that is quite high or quite low, it is possible that you are compensating for other problems.

Tapping the Side of the Portafilter
      Years ago, advice concerning knocking the loose coffee from the sides of the basket was ubiquitous. The advice was to use the top of the tamper to tap the outside edge of the portafilter body to knock the grounds around the inside of the basket back onto the coffee. Some tampers still come with a softer piece of plastic embedded in the top of the tamper to protect the tamper as well as the portafilter from damage when tapping the loose coffee off the sides of the basket.

      I advise that you NEVER tap the sides of the portafilter after tamping. It's a matter of risk vs. gain. The gain is slight (nonexistent, actually). A bit of loose coffee on the edges of the filter basket will have little impact on anything. The risk is that you might dislodge the important seal between the coffee and the basket, or cause a fracture in the coffee puck, either of which will cause channeling during the extraction.

Tamping Procedure
      Over the years I have adjusted my tamping procedure many, many times and have recently found a simple tamping process that seems to be working quite well. After dosing and distributing the coffee as described above:

     A challenge: If you want to test your dosing and tamping skills, carefully and gently turn the portafilter upside down. Do this over the doser or over a bowl! If all has gone well up to this point, nothing will happen other than the remaining loose bits of coffee on the portafilter will fall off. If all has not gone well up to this point, the coffee will fall out of the portafilter and you will need to begin again. I hate when that happens!

      TIP: If you have a bottomless portafilter it can be difficult to hold it steady when tamping. I use a tamping mat on the edge of the counter. You can also use a piece of hardwood about 3/4" thick upon which to rest the bottom of your bottomless portafilter when tamping. This gives clearance between the portafilter handle and the counter making it easier to hold the portafilter steady. It also protects the counter top. There are tamping mats available which wrap over the edge of the counter which are excellent for this as well.

      When you have "mastered" dose, distribution, and tamping, (and have stopped laughing after reading the beginning of this sentence... "Mastered..!? He must be kidding!"), the grind is the one adjustment that the barista most often makes to alter the extraction for the best taste. Based on the scientific method of controlling an experiment, you need to keep all factors constant except one— the variable. For any given coffee, once we find a dose mass that works, the grind is the one variable we use to control the extraction.

      It is difficult to convince a new home barista that a $300 grinder is an entry level tool, and that they would be best served spending $650 to $800, or even more. The best way to look at this is that the espresso machine is an accessory to the grinder. I can make a decent espresso with a $7 espresso machine I bought used at a thrift store when paired with my quality grinder, but my $2500 espresso machine will turn out poor espresso when paired with an "economy" grinder.

      A quality espresso grinder is a precision instrument that creates particle sizes in a very specific range. Better grinders have adjustment capability of less than 0.001" (0.025mm). The mounting of the burrs keeps the two burrs in very close parallel alignment and the bearings in the motor hold the shaft in precise alignment as well. All of this design and engineering and the metal that makes it all possible becomes expensive. For a specific example, a plastic carrier for the top burr costs less to manufacture than a heavy brass part.

      When shopping for a grinder specifically intended to be used for making espresso, I highly recommend using a stepless grinder— one that has no "clicks" between settings. The infinite level of adjustment can make a difference. Some grinders touted as being excellent home espresso grinders have click stops which are such that one "step" equals about four or five seconds of extraction time for the same volume of espresso. If you are interested in fine-tuning your espresso, these stepped grinders can be insufficient. Even though one click can be as small as .001" of burr spacing in better espresso grinders, this is too coarse for a serious enthusiast. Using a grinder with click stops, you may only have one or two choices when it comes to grind adjust.

      There is also a matter of particle-size distribution. The particle size needs to have some variation— smaller particles are needed to fill the gaps between the larger particles, but the amount of dust needs to be kept to a minimum as this can end up in the cup and will add bitterness. If the burrs are not held in precise alignment and held firmly in place during the grinding process, the particle size variance can be too large for best results.

      I mention the above because you may be stuck using a grinder that has limitations in the way it adjusts. If the top burr wobbles, or if the lower burr has excessive run-out, this will limit how effective changes in all the other procedures will be. All of this is part of why better grinders are so necessary as well as expensive— they are precision tools made with quality materials.

      While the above information concerning grinders does not give much assistance when it comes to curing problems, I have included it because you may be at a dead-end when it comes to improving your espresso. If you go through this article and cannot make better espresso, you may very well need to make a change in grinder to step up to the next level. If you have a quality grinder then you may be due for a new set of burrs. Do an Internet search for information on your grinder as there are other enthusiasts out there who may have discovered modifications to make your grinder work better for espresso.

Burr Age
      How old are the burrs in your grinder? Whatever grinder you are using, it is only as good as the condition of its burr set. The life of a set of grinder burrs is limited, and the amount of coffee they can grind is usually overstated, at least when it comes to espresso. During the time I owned my previous flat-burr grinder I changed the burrs about every 18 to 24 months, and I could always tell the difference between the new and old set of burrs. At around $30 per set it was like getting a new grinder every couple of years or so. Much like shock absorbers (or strut cartridges) on a car, you may not realize how worn they are until you get new ones. Better grinders tend to have burrs made of better materials and so they might be expected to last longer. That's a good thing because the burrs for some commercial grinders can cost well over $100!

Grind Adjustment
      Of all the adjustments and changes to be made by the barista, adjusting the grind is the most straightforward and has the potential to make the greatest change in the espresso. But you have to be able to control all other factors to as great of an extent as possible to get the most from this adjustment. For example, making the grind a bit finer, but mis-dosing will cause you to think that the finer grind was an incorrect choice. This is why I have placed adjustment of the grind after dosing and tamping.

Use a Finer Grind if:

Use a Coarser Grind if:

Let's take a look at the grind range in this way:

      But how to find that setting? Many problems are created by using a too coarse grind. Why is this a common problem? It might be for fear of damaging the burrs or from recommendations read online or from the manufacturer. Whatever the reason, it is a lot easier to find the correct grind by working from a grinder that is adjusted too fine towards a more coarse setting than it is to work from the other direction. I am not sure why, but in my personal experience as well as the successful advice I have given to many other home baristas, grinding finer has often been the solution when there was a problem with the espresso.

      With all other procedures working well (dose, distribution, and tamping), grind finer and finer until the machine is choked or nearly so. That is, until you get about one ounce or less in twenty seconds. Now slowly adjust towards a more coarse setting using the smallest "steps" possible, taste testing after each adjustment. As your skills improve, the "Correct" or acceptable range will be easier to find and will also become more narrow. From there the amount of time it takes to complete the extraction becomes much less of a factor and your palate becomes the best indicator to assist in finding the correct grind. Unfortunately, some grinders will only offer one click finer before the grind becomes too fine or one click more coarse before the coffee is too coarse. This removes an important tool from the barista's hands when it comes to improving their espresso. If you get to that point it is probably time to modify your grinder or replace it.

      As I mentioned previously, all the various procedures when creating espresso are interrelated. Don't be surprised if you have to make an adjustment to your dose after changing grind. Knowing what to change and when to change it comes with experience and consistency in your procedures. When you can make a small change in grind, and you can taste that change in the cup, and that change is consistent pull after pull, day after day, you are at a point where you are gaining control over the process.

      Note that "gaining" as used above indicating present tense. The fact that we will never have full control over this process is one of the things that has held my interest through the years. Making espresso is easy. Making good espresso is not that hard. Making excellent espresso every time is impossible. The world's best baristas will toss a shot into the sink now and again. Remember that I began this article after nearly 8 years of daily experience at home, and after over ten years I am still learning! I think that the saying, "Pride cometh before a fall" was written by a barista. Just when a great pull comes along, don't be surprised if the next one falls short of your expectations. It happens.

Grinder Cleanliness

      The grinder is an area that is often overlooked when it comes to keeping things clean. Ground coffee stales in minutes when exposed to air. After a few hours, or overnight, the coffee left from the last session will be stale and will surely affect the taste of the next session's espresso. To clean out the grinding chamber you could simply grind a small amount of coffee and discarding it. Other grinders take more effort to clean. Some of the commercial grinders have access problems unless modifications are made. Consult your grinder's manual for details on your grinder. Some general areas to watch:

The Dosing Chamber - At the end of each session, if the grinder will not be used again in the next ten or fifteen minutes, the chamber should be emptied and brushed clean. There are special grinder brushes for this, but a small basting brush or paint brush will work well. A brush without a metal ferrule is best to avoid scratching the grinder.

The Exit Chute - Most grinders will retain an amount of coffee in the chute that connects the grinding chamber to the doser or exit port. How to clean that will vary depending on the grinder and how easy (or difficult) it is to access. Grinders do not come with tools to access that area and so you will need to be creative to clean that areas if your grinder retains coffee there. If the chute is not accessible you will have to run a small amount of fresh coffee through it and discard what is dispensed to rid the path of stale, left-over coffee grounds.

The Grinding Chamber - There are grinders that make access to this area quite easy. Others require tools to disassemble portions of the grinder to access this. The easy way to clean the burrs and grinding chamber is to use a grinder cleaning product. These are quite valuable if your grinder is difficult to disassemble or you are not handy with tools. Beyond that, disassembling grinders over and over will cause wear on the threads which can shorten the useful life of the grinder, so keep the frequency of this procedure to a minimum.

   Different grinders may benefit from certain modifications. As an example, the Rocky likes to have teflon tape applied to the threads of its burr-carrier to stabilize the upper burr. One modification that I have done to all my grinders is to remove the portafilter forks. I find these just get in the way and keep you from moving the portafilter around to get the best possible distribution of the coffee. It also makes it inconvenient if you want to grind for drip or other brewing methods besides espresso. Check the various online coffee and espresso forums for guidelines on how to accomplish these modifications.

THE ESPRESSO MACHINE

      Much like your grinder, you may be stuck using the espresso machine you currently posses and you have to "dance with the one you brung." Let's examine the machine and see if there is anything you can do to get it to produce better espresso.

Cleanliness
      It is crucial to have a clean machine. This is not only for sanitary reasons and the proper function and lifespan of the machine, but also for quality of the espresso. There are various areas that need to have regular attention.

NOTE: Before proceeding with any cleaning procedure or using any cleaning product on your machine be sure to consult your manual or seller.

3-Way Valve - Consult your manual if you are not sure whether your machine has a 3-way valve. If your machine can be backflushed, consult my article 3-Way Valve Hows and Whys. This article covers, in detail, why it is important to backflush which should answer any questions on this process. If you are not familiar with the process, read my lesson on How to backflush. There are a few machines that use a non-standard placement for the 3-way valve, so be sure it is safe to backflush your machine before proceeding with this process.

      Internal passages which become dirty with coffee residue may taint the taste of the coffee and can slow the flow of water to the coffee during the brewing process. A dirty 3-way valve can leak creating low brew pressure and can also lead to low water level in the boiler which can damage the heating element or various gaskets.

Steam Wand - Keeping the steam wand clean is simple. When making espresso I always have a dish towel over my shoulder and before beginning each session I wet a corner of the towel with water. You may just want to keep a wet dish rag next to the machine when you are working. This is used to wipe the end of the steam wand off at the end of each steaming session. You should also give a blast of steam after use to clear the wand of any milk that may be in the tip's holes or may have gotten into the wand. I do this regularly and have never had any milk get into the steam wand.

      It is also a good idea to remove the tip occasionally. Bits of debris such as hard water deposits can get in there and clog the hole(s) lessening the effectiveness of the steam function.

Brewgroup- The brewhead's area needs to be kept clean. Coffee oils and coffee particles can build up on the screen, behind the shower screen, on the face of the brewhead, and on the brewhead gasket. The cleaning of these areas will vary from machine to machine, so it is difficult to comment specifically. Using a brewhead brush to scrub the area down, flushing some water out, then wiping out the area with the wet towel works fine if done on a daily basis. If your machine has a standard 3-way valve, doing a plain water backflush once a day or once a week (depending on use) and a detergent backflush one a month is usually fine for home machines. More often is somewhat more desirable than less often. If that sounds like overkill, after a week of not cleaning take out the shower screen of a cool machine, wipe your finger across the brewhead, and smell that residue! Notice how easily that dark residue comes off. It can just as easy get into your coffee. If you are still not convinced, taste what you just wiped off on your finger! E-61 machines should not be cleaned with detergent too often as it can cause accelerated wear to internal parts of the brew group by washing out lubricant. Because of that, doing a clean-water backflush at the end of every session is more important than with many other machines.

Shower Screen and Basket - These should be regularly examined. Check for clogged holes, cracks, bad welds, or any other deformity that could affect the espresso. If these look dirty or clogged, soak the parts in a strong, hot solution of espresso machine cleaner. Remove and scrub them with a stiff brush a few times during the soak. If the cannot be cleaned or show damage, replace them.

Removable Parts - Shower screen, shower head (distribution device behind shower screen), filter basket, portafilter body and spouts, and other related parts should be removed from the machine and soaked in cleaner about once every month or two depending on how much use the machine gets. Most machines have the shower screen attached with a screw or bolt. if you have an E-61 brewgroup, Consult my article How to Remove an E-61 Shower Screen and Brewhead Gasket.

      As always, consult your owner's manual for details on how to keep your machine clean.

TEMPERATURE

      Water temperature is crucial in the production of espresso. What the best temperature range is a matter of debate and personal taste, but we can generalize and say between 195 and 203 F (91-95 C). Variables such as altitude, roast level, blend, how the espresso will be used (straight or in a milk-based beverage), accuracy of the measuring device, and personal taste all determine the "best" brew temperature. Some experts state that a flat line temperature within 0.5 F or less is critical while others say that a descending temperature curve is best. The bottom line on this is that you probably have little or no control over whether the temperature stays flat, drops or rises during the extraction. Even if you have some tricks you can do to affect the starting brewing temperature, the ability to do so consistently is greatly limited, so for most home baristas it is best to let the machine do what it does and not worry about it until your budget and obsession allow you to be concerned.

      Temperature control is another matter. Manufacturers are beginning to equip some machines equipped with adjustable thermostats, usually in the form of a PID device. Heat exchanger machines have long had the ability to have the boiler's temperature adjusted. Some of the more enthusiastic home users are equipping their own machine themselves with PID controls.

     The most important factor when it comes to temperature is to have a machine that can perform the same way from one pull to the next. How you achieve that depends on your machine, the amount of time and effort you want to put into it, and the volume of your bank account. If you have a single-boiler machine then you will likely have to temperature surf, time surf, or add a PID control. Temperature and time surfing methods vary from machine to machine, but basically the procedure involves pumping water out the hot water wand until the thermostat turns on the heating element, stopping the hot water function, then waiting a predetermined number of seconds before turning on the brew switch. More information on this can be found in my Brew-Temperature Control article.

     If your machine has a pressurestat you can adjust that to control boiler temperature pressure which is an indirect way to control temperature. The range of that adjustment will affect the amount of steam power as well. Another factor is whether the machine is plumbed or has a reservoir since the temperature of the incoming water will vary. Some machine (such as those with E-61 brewheads equipped with thermosyphon heating) require that some water be bled out of the group before pulling a shot for best results. It is beyond the scope of this article to address how to control temperature in every type of machine. I suggest you consult one of the many online forums for more detailed information concerning the best way to control the brewing temperature of your machine.

      Generally, better machines with larger boilers offer greater temperature stability. They also offer the ability to pull multiple shots, one after another, as well as to be able to steam and pull shots at the same time. Better machines with larger boilers also cost more. Machines are now being sold for home use that feature dual boilers— one for brewing espresso and one for steam. As you would assume, these can be quite expensive.

      Measuring brewing temperature can be done simply. While not very accurate, it will give you an idea if you are close. Read my How To - Brew-Temperature Check article on how to do that.

BREW PRESSURE

      Most low-end espresso machines have absolutely no viable way to adjust brew pressure. Some mid-range machines have adjustable valves to control brew pressure. The better machines not only supply an accurate adjustment for brewing pressure they also have a gage on the machine so that brew force can be monitored during the extraction process.

      If your machine has no adjustment then there is not much you can do about brew pressure. Even if your machine is adjustable, if it doesn't have a gage, the value of the adjustment is questionable. Even machines with pressure gages mounted as "standard equipment" have questionable value as the gages are often of low precision. To make best use of the brew pressure adjustment you will need to either purchase a pressure gage that mounts to a portafilter or cobble one up on your own.

      For a machine equipped with the adjustment and a gage, the actual adjustment procedure will vary. Some machines read the pressure a long distance before the brewhead and so the pressure at the coffee will generally be less due to friction loss through the brew path. Since around 9BAR (135 PSI) is the recommended brewing pressure for espresso, setting the pressure at the gage to about 9.5 bar is a good place to start. Without a pressure gage attached to a portafilter there is no other accurate way to judge brewing force.

      Having the correct maximum pressure set in the machine will establish a baseline to which the grind will be adjusted. If the machine is capable of sending a maximum 150 pounds of water pressure to the coffee, in order to sufficiently resist the flow of water to get the "correct" volume of espresso in the desired amount of time, you may need to grind finer. This will cause over-extraction and a poor-quality espresso. On the other hand, with the brew pressure too low, you will have to use a too-coarse grind to compensate and this can lead to under extraction. If the machine has a gage, use it regularly to monitor the gage the extraction to assure that you have the correct grind and dose to keep the brewing force from being too high or too low.

WATER QUALITY

      The quality of your water is quite important for a couple of reasons. Most importantly, it affects the taste of the espresso. Water that contains too high of a mineral content or has too few minerals will adversely affect the taste of the espresso.

      At the same time, water that is too high in some minerals (like calcium or lime), will cause mineral deposits to build in the boiler and other parts of the machine which carry water. If not dealt with these can eventually cause blockages, and can even cause the heating element to fail. Water devoid of minerals (processed through distillation or reverse osmosis) may cause leaching of copper pipes and will cause the water level sensors in HX boilers to malfunction leading to a pump that does not turn off, overfilling the boiler.

      Minerals will likely build up in the boilers of all espresso machines when water with any mineral content is used. Descaling is a process of sending a special cleaning agent through the boiler to remove the hard water deposits. Citric acid can be used, and there are commercial products for this purpose as well. See my article How to Descale for more information. Jim Schulman's Insanely Long Water FAQ is the best resource I know of for information on water quality and water treatment.

      Jim's article talks about the level of total dissolved solids (among many other things). To measure the TDS of your water you can pick up an inexpensive electronic gage. Do a search for "TDS meter" on a shopping search engine or at your favorite auction site. They often sell for around $20 or even a bit less. Even these devices do not tell the whole story. Scaling is a function of general hardness (GH) and alkalinity (KH). Both have to be present to cause scaling. The GH KH Test Kit from API/Aquarium Pharmaceuticals, Inc is an excellent way to check your water. One test kit lasts for many, many dozens of tests and can be had for about $10 to $15.

LIMITING FACTORS

      In all of this, regardless as to how careful and precise you are in attempting to control every step, there will be limiting factors as to how well you can duplicate your last successful espresso. What worked well for your coffee when it was three days old may not work when the coffee is a week old. The brewing temperature range may not be very well-controlled in your espresso machine. The adjustment steps of your grinder may be too coarse. Work hard to control what you can control, and don't worry about the factors that are out of your control.

      It seems somewhat illogical, but the entry-level espresso machines aimed at first-time purchasers of home espresso equipment are the most difficult to control and thus are the most difficult with which to create good espresso repeatedly. That is the factor that drives so many to upgrade, or drives them away from espresso. Push your equipment to produce the best it can until you have developed your skills to produce the same flavors as consistently as is possible with what you have.

      To a great extent, your level of success depends on your level of commitment. How much effort you put into the process, how much attention to detail you are willing to exert, and how much patience you have. Good espresso is a journey that is ongoing and never ending. The destination is never more than a stop-over, and the journey begins anew the next morning. I have been on the journey for nearly ten years and am still on the road. Have a good trip!

THE INTERCONNECTEDNESS OF ALL THINGS

      Fans of Douglas Adams will know what that means. I have mentioned this in passing throughout this article, but it is important to address on its own merit. All factors are interconnected when it comes to making espresso. If an espresso comes out poorly, what caused it? There are some diagnosis that are easy— an example is channeling. If there is a big hole in the puck when you remove the portafilter after a pull it should be fairly obvious that channeling took place and you most like have a problem with dose or distribution. But other problems may be more difficult to find the cause. If the espresso is bitter, was it caused by too coarse of a grind, not enough coffee, or too high of a brew temperature? Was it all of those? Some of those?

      The only way to deal with this is to become as consistent as possible with all the things you do. Eliminating or minimizing as many of the variables as possible will make diagnosing problems a lot easier. This comes from practice and experience. You will never reach perfection. Even professional baristas will toss shots into the sink just from looking at the way the shot issues forth from the spouts.

      Here's a good example I recently experienced- I had roasted and just about finished using two batches of coffee from a new supplier but had been having some of the poorest pulls I had experienced in years. While the taste of the espresso was improved with the new beans, the extraction was odd. It started with multiple streams in a doughnut pattern on the bottom of the basket (using a bottomless PF), then joining together in one stream after a good 10 seconds of extraction, then after about five more seconds the flow looked like an inverted bell hanging off the bottom of the basket, and very thin in viscosity. Sort of like the portafilter was trying to blow a bubble that would not release into the air. While I had been getting good pulls producing over 2 ounces of crema with the old coffee, I could not get this to happen with the new coffee.

     Mind you, even with this poor extraction performance the espresso tasted better from the very first pull than it had with my old supplier. But what was the cause of these abnormal extractions? It turned out to be overdosing. The new coffee was expanding a lot more than the old supplier's coffee, and I discovered that by dosing less, and the espresso extractions immediately improved.

      You may never achieve the level of expertise it takes to know how a shot will taste just from watching the flow from the portafilter, but depending on your equipment, coffee, and level of commitment, you can produce coffee beverages better than available at most coffee shops by using the above information and modifying it to work for you. Remember, all "rules" about making espresso are just starting points. The "art of espresso" is your ability to adjust the rules to get the best possible espresso from your beans, procedures, and equipment.

      Hopefully these tips, tricks, and insights will help you make better espresso.

CHEERS, and GOOD LUCK!