I wrote the following (exhaustive) workflow guide to using a Gaggia Classic (or single boiler dual use) home espresso machine a few years ago. Things have changed, but for those using this type of machine and just starting out I think it can provide a useful frame of reference. I'm sure you'll need to modify some steps to make them your own, but hopefully this provides some guidance. A pdf version with quick reference guides is linked below as well.
In an attempt to compile a procedure or reference guide on using your espresso machine, specifically a single boiler / dual use machine, and even more specifically a Gaggia Classic, I am going to detail my step by step process flow of making a few drinks. By no means is my word gospel or the only way to establish your work flow, but I’m hoping it will create a more comprehensive list of what needs to take place and why all in one document. I learned the steps that are incorporated into my workflow by reading and watching as much as I could. My workflow will vary day to day based on what type(s) of drink(s) I’m making and how much time I have. I will list the elaborate and thorough process with notes and alternatives incorporated throughout and a quick reference summary guide to follow.
1. Assuming your machine has been previously primed, turn your machine on and allow it to warm up for 30 minutes with the portafilter (PF) locked in.
2. Because I’m taking my time when making the drinks and will allow the boiler time to recover and re-stabilize, I will re-fill/re-prime the boiler by opening the steam wand and turning the pump on until I get a steady stream of water through the steam wand. You’ll notice that in the first few seconds the water is sputtering; that is the steam or the superheated water sitting in the boiler; you are purging that out by introducing fresh water into the boiler by doing this.
a. *I always keep a small (1-cup glass, Pyrex) pitcher under my steam wand – all Gaggia Classic steam wands leak. When performing this step the water from the wand will go into this pitcher. I will also put my cup under the grouphead, as some water will come out of it as well. I then pour the water from the pitcher into this cup, which is used to preheat the cup – no water wasted.
b. *Although not recommended, you can get away with a slightly shorter warm-up time (15-20 minutes) by flushing water through the PF to bring everything up to temp quicker and using that water to preheat your cup. *Make sure to allow a little bit of time for the boiler to recover after the warming flush(es).
3. Measure out your dose(s). For my daily routine, this will be two doubles – I single dose my grinder so, I measure out the whole beans in metal restaurant ramekins. With my equipment and the OEM supplied double basket, I will dose between 16 and 19.5g depending on the coffee used.
a. *I use the ramekins because they perfectly fit in the throat of my grinder’s hopper and minimize the popcorning effect of the grinder.
4. Dry your PF/basket and grind your first shot.
a. If you need to WDT or dose into the PF basket, now’s the time. The grinder I use is pretty consistent and I can get a good even dose by moving the PF around while grinding to make sure I’m evenly filling the basket.
b. *Some of the really obsessive will weigh again after grinding to account for retention. This is good when first starting or testing your grinder, but I know my grinder’s retention is less than .2g, so I no longer weigh after grinding.
5. Settle/distribute/tamp: I give the PF 2-3 vertical thumps on the counter, keeping the basket as level as possible, which settles the grounds and usually does a good job of evening out the distribution, provided my aim was good when grinding. *In general, less is more. If you did a good job of evenly dosing or grinding into the basket you shouldn’t need to play with it much.
a. My current tamper is slightly small for my basket so I need to seal the edges, a center tamp alone would create a donut extraction. This can be done by using the NSEW or a nutating tamp, I find nutating more consistent and faster. Using the weight of the tamper alone I nutate as evenly as possible. I then lightly and as evenly as possible compress the grounds with the pressure of my fingertips around the perimeter of the tamper only. I then do a traditional tamp at approximately 30lbs, lift up to suction the grounds off the side, rotate my arm 90* so my finger and thumb are now on the other sides of the basket, tamp once more and polish with the weight of the tamper alone (very lightly). *It is possible to disturb the puck when lifting the tamper if using a tighter/more precise fitting tamper.
6. Temp the shot (temperature surfing) for machines without a PID. When first starting, I would say to not worry too much about this step, but after you get the hang of it, you were hopefully watching the cycles of the boiler (ready light) while grinding and tamping. We know the temperature range of most SBDU and the Gaggia Classic is quite wide, and that the temp will continue to rise for a few seconds after the ready like clicks back on indicating the heating element is now off.
a. For beans that favor the cooler end of the temperature spectrum, I will often start the pull 20-30 seconds after the ready light kicks on/boiler turns off (assuming this is not the boiler’s first heating cycle after the long flush of fresh water and what’s in the boiler is relatively stable at this point; i.e. it has been a few minutes since your initial boiler fill).
i. *Typically, if you’re not pulling a shot right after the heating cycle or bumping the temp up via the steam switch, the heating element will kick on mid to late pull. I haven’t measured the brew temperature to verify what adverse effects this might have, but knowing the machine has a wide temperature band, I try and keep things as stable as possible and associate that pattern with a shot that dips quite cold in the middle and then kicks back up at the end.
b. For roasts that I know favor a mild to warmer pull temp or if I haven’t seen the boiler kick on recently, (which indicates the temperature is on the decline) I will “bump” the temperature in the boiler up by activating the steam switch for 2-5 seconds followed by a 2-4 second rest and then begin the pull. When using this method, the heating element usually won’t kick back on until after the shot.
A bottomless or naked PF makes it easier to identify the blonding point, but the streams from a spouted PF will change as well. Thin, steady, 'rat-tail' like streams are what you're going for.
7. Cut the shot off at the blonding point. Don’t get too caught up in 28 seconds or 2oz, but learn to identify the signals of when the shot is about to go blond, indicating the extraction is over. Blonding is seen by a sudden change in color of the stream (much lighter “blond”) and usually the viscosity or the thickness/texture of the shot changes to a more watery/runny flow. This indicates the coffee has been fully extracted (or at least the parts we want have) and this blond portion of the shot is going to taste bitter, burnt, have little crema and thin mouthfeel, all things we don’t want. Stopping the shot at or just before the blonding point will allow an unintended short or long pull to still be drinkable.
a. Most properly pulled doubles will extract 1.5 – 2.25oz in 25-32 seconds, give or take on either side of volume or time. A more accurate method of measuring extraction is to weigh the yield of the shot, to create a brewing ratio (i.e. 18g in, 36g out = 50% brewing ratio). On a properly executed shot the blonding point will occur in line with the desired brewing ratio and extraction time. Adjusting grind and/or dose will help manipulate and dial in the shot to achieve desired your desired parameters. Your palette is the ultimate judge for how and what to adjust to reach your desired tastes.
8. Remove the portafilter, knock out the puck and run some water through the grouphead into that handy pitcher you have at your station to flush out any grounds stuck to the screen. Take your cloth and wipe out the excess grounds in the PF, rinse the basket if needed, and I’ll usually wipe the screen and PF groove with the towel as well. If you’re done making drinks for the day, proceed to step 15.
My typical weekday involves either a straight shot to enjoy while getting ready and an Americano or latte to-go as I head out the door or a two shot Americano or latte straight into the to-go mug. Since the former does not vary much from pulling two separate drinks, the following steps detail pulling back to back shots for my two shot Americano or latte. Before I start the process, I fill the mug with water and stick it in the microwave for 90 seconds to pre-heat it. I will sometimes pull a third shot for the Mrs. as well, but the workflow from here, to pull consecutive shots would remain relatively constant, so I will just go through the latte since that is more in depth. *Note, when making an Americano I will use fresh filtered water and microwave it to warm, and not use the boiler water from the machine, which will empty the contents of the small boiler and cause it to loose temperature.
9. Now that the group and PF have been prepped for the next shot, go through the grind, tamp, temp process again for the following shot. I would estimate that 2-3 minutes pass between shots. Some will argue that the Classic needs more time to recover than this, but I will “work around” this slightly with the steam switch temp bump.
a. *If I were making back to back espressos, I would prefer to give a little more recovery as any temp deficiencies won’t be masked by milk or the additional hot water of an Americano.
10. Pull your second shot. If I know I’m making a latte, I will get the corner of my “cleaning” towel wet during the pull of the first shot and then fill my previously chilled milk pitcher while my second shot is pouring.
a. *It’s always good to store your (clean) milk pitcher in the fridge or freezer. Keeping things extra cold allows you more time to work the milk via a lower starting temp.
11. The second shot has ended, knock out the puck, use the non-milk/cleaning rag to wipe the grounds out of the PF basket before they dry on there, and I will usually give a quick wipe to the screen and knock off any grounds on it, but the cleaning flush will combine with the cooling flush in a minute.
Steaming Milk
a 3oz cafe macciato made on the Gaggia Classic
12. Flip on the steam switch. I typically do this before step 11 and perform step 11 while the boiler is getting up to steaming temp. Shortly after the steam switch is flipped on, open the steam knob to purge the water out. You only want to let just the water out and immediately close it; we don’t want to let the steam escape. Depending on how much water came out the first time, I will quickly open and close the steam knob once or twice more to purge any remaining water to avoid having wet steam.
13. Steam the milk. This takes practice, there are a lot of good youtube videos showing what to look and listen for, watch a lot of them, a few are linked at the end of this guide.
a. Start with the tip of the wand about ¼ - ½” away from the side of the steaming pitcher with the pitcher held on a slight angle.
b. Gradually open the steam knob with the tip of the wand just below the surface of the milk so you don’t blow the milk out of the pitcher.
c. Stretch the milk by lowering the pitcher to start getting the “chu, chu, chu / tearing paper/ kissing/sucking sound”. *Most tutorials will teach you to introduce air in the first part (stretching the milk), and then texturize in the second half of steaming. I try and incorporate the texturizing part from the beginning by having the steam wand closer to the side of the pitcher and the pitcher slightly on an angle so I’m able to get a head start on creating the “whirlpool effect”.
d. Texturize the milk once you have incorporated enough air (stretched the milk enough). Raise the pitcher slightly to submerge the tip of the steam wand enough to no longer introduce any more air, but keep it towards the surface to get the milk spinning or the ‘whirlpool effect’ rolling.
i. The transition from stretching to texturizing generally takes place around the time when the side of the pitcher begins to feel warm, which means it has started to exceed your body temperature or about 100*F. If I don’t feel I introduced enough air, the transition may take place later and vice-versa if I introduced a lot of air at the beginning – I will need the extra time texturizing to incorporate it.
e. Stop steaming by closing the steam knob and keeping the tip submerged once the pitcher becomes hot enough that you can only keep your hand on it for a second or two. This indicates it has reached the optimal temp, between 145-155*F. You do not want to keep steaming beyond this point, the milk will start to scald and you will lose the sweetness you created.
f. Turn off the steam switch. Wipe the milk off of the steam wand with the damp corner of your rag, and open the steam wand briefly once or twice more to purge out any milk in the wand.
g. *Especially when steaming larger quantities of milk, it’s helpful to begin steaming a few seconds before the steaming ready light kicks on. When that light kicks on, it indicates the boiler is up to steam temp and no longer heating. By beginning to steam just before the light kicks on, you can extend the amount of time the boiler stays on to create the steam, thus extending how long you can steam for and prolonging your steaming power. *I find I can hear when it is about to ready, but each machine may differ; eventually you should be able to develop a feel for the amount of time it takes.
14. Bring the boiler back down to brew temp/re-fill the boiler with water. There are two ways to do this, the first being to follow the priming steps again to fill the boiler/release the steam, and the second to activate the brew switch to release the steam and superheated water out of the grouphead. I do a combination of both, I find if I open the steam/hot water valve and activate the pump, the initial release of steam is so powerful and sputtering that water sometimes sprays or splashes. To avoid this, I activate the pump/brew switch first and run water through the grouphead. The first few seconds will be flash boiling steam, and water will gradually begin to flow. (I capture this water in that handy pitcher I keep at my machine) *While this is taking place I’m typically swirling my milk pitcher to prepare it to pour into my cup. Releasing that first bit of super-heated water gives the peace of mind that I have (at least partially) refilled the boiler with some water as to avoid vapor lock while I finish preparing my drink.
a. *Being that I have now poured the contents from the shot glass into the to-go mug, I pour the water that was just collected from the pitcher into the shot glass so it’s easier to clean later.
b. Now that I have finished making the drink, I return the utility catch-all pitcher (not the steaming pitcher) below the steam wand, open the steam valve and turn the pump on to purge the last remaining bit of steam out of the boiler and make sure I have refilled it.
i. While this is taking place, I use my group brush to clean the grouphead, the PF groove, and shower screen since water is slowly coming out of the grouphead.
15. The machine is now re-filled, cleaned, and ready to either be backflushed, shut down for the day, or left to sit idle/recover for later pulls. *Only backflush machines with 3-way valves.
a. To backflush with water only, I will then insert the PF with the blind disk and run the pump for about 8-10 seconds or until I hear the pump begin to labor. Turn the pump switch off to backflush water back through the 3-way valve into the drip tray.
i. I will typically remove the PF and see if there are any stray grounds in the blank basket (dump them out if there are), and I may repeat this step depending on how recently the machine was cleaned, how many shots I pulled, and how “messy” the coffee is. *Typically darker roasts will leave behind more residue and stick to the screen more, requiring more cleaning/backflushing.
ii. *At 2-3 shots pulled per day, I will backflush (with water) every other day or so, depending on how “messy” the coffee I’m using is. Backflushing with detergent will take place every 2-4 weeks depending on use. *Regular cleaning with detergent keeps things tidy, but done too often the chemicals will cause premature deterioration of gaskets and seals.
b. If I am shutting the machine down for the day, I will use my clean towel to wipe the screen and grouphead, pour the clean water I just collected via the steam wand flush through the PF (plus any additional water as needed from the kitchen faucet) to clean it out, and dry it off as well. My dirty or cleaning rag will wipe off the drip tray, and I am then finished.
Glossary
Priming: Filling the boiler with water, or pulling steam and hot water out of the boiler (by filling it with fresh water) Directions found here: http://www.gaggiausersgroup.com/index.php/index.php?action=ezportal;sa=page;p=21
WDT – Weiss Distribution Technique: Stirring the grounds in the filter basket to create an evenly and uniformly distributed dose. Directions here: http://www.home-barista.com/weiss-distribution-technique.html
Nutation or Nutating Tamp: A rotation of the tamper on an axis that would resemble a spinning coin that is wobbling and oscillating as it comes to rest. Explained here: http://www.home-barista.com/tips/nutation-how-to-do-it-right-t12625.html
Reference Links
Brewing Ratios for espresso beverages: http://www.home-barista.com/tips/brewing-ratios-for-espresso-beverages-t2402.html
Adjusting grind and dose to taste: http://www.home-barista.com/tips/espresso-101-flavor-adjustment-diagram-t27949.html
Milk steaming technique: http://www.home-barista.com/tips/learning-latte-art-with-steamed-soapy-water-t7248.html
http://blog.vervecoffeeroasters.com/2013/04/04/vcr-street-smarts-11-milk-steaming/
Notes
This guide is not comprehensive and assumes a certain degree of knowledge of terminology, process, and barista mechanics.
Equipment: Some of the steps in this article apply only to SBDU machines. Using a heat exchanger (HX), double boiler, or hybrid machine, such as the Quick Mill Silvano or Crossland CC1, will require modifications, omissions, and additions in certain cases.
My Gaggia Classic utilizes the OPV mod to 10 bar pressure in the blind filter, Rancillio Siliva V1 steam wand, and Tex’s steam valve mod to allow the needle to be removed. Except when splitting shots, I almost exclusively use the bottomless PF.