I decided to put the recommended temperature surfing standard times [source: Web log of Mythos, Rini, Simon and Debbie (MRSD), here] for the Rancilio Silvia coffee machine up as diagram (rather than text print out).
For anyone that also wants this graphically, here you go.
How to temperature surf a Rancilio Silvia step by step
The line by line instructions cited from the source [Web log of Mythos, Rini, Simon and Debbie (MRSD), here] :
- Warm up the machine for at least 30-60 min (or brew at least 2 x double shot espresso and throw them down the drain.. not recommended though)
- Current State: Indicator light = OFF
- Turn ON brew button to run cold water into boiler until indicator light is ON
- Reason: Cold water makes the boiler temperature drop and triggers the boiler to start again when temperature is below 86 C/186 F
- Wait till the indicator light = OFF and immediately start a stopwatch (iphone or watch). Now, the boiler temperature is 102 C/215 F
- Precisely wait for 30 seconds
- Reason: The internal temperature keeps climbing because of pressure inside the boiler even the boiler is turned off. It reaches at 116 C/240 F (which is 30 seconds) and boiler starts to cool down by itself
- Turn ON brew button to run cold water into boiler for 5 seconds.
- Reason: This procedure is called “cold flush” to bring down the temperature to 110 C/ 230 F, you should see a lot of steam in first 3 seconds *
- Turn OFF brew button at 35 seconds (read stopwatch)
- Now, put the portafilter + cup under the brew head (You have around 15 seconds time to do so)
- Turn ON brew button at 50 seconds (read stopwatch) to brew your coffee. Note: At this point, cold water comes in continuously for the next 25 seconds + temperature offset between the brewhead and boiler, so the final average temperature would be ideal when it touches the coffee which around 198 F to 204 F (92 C to 95 C) for the next 25 seconds.
- Reset stopwatch and start it from 0 (Stopwatch at 0 seconds)
- Your espresso should starts brewing, if tamped and grind properly, your espresso should finish at 25-30 seconds.
- Note: the boiler indicator light = OFF all the time until the end, the indicator light will turn ON automatically at around 20 seconds **
- Turn OFF brew button at 25-30 seconds, depends on coffee, tamp and grind
* If you don’t see steam, your machine has not been warmed up enough in (1)
** If you don’t warm up in (1), the boiler isn’t hot enough and the boiler starts to kick in too early, giving you the wrong temperature.
Supplement: temperature surfing a Solis Crema SL 70 coffee machine
I am currently trying to use up (as in: until it falls apart) an old Solis Crema SL 70 coffee machine I still had sitting around. Playing across the options of different temperature surfing results, I find that emptying a whole 2 DL cup of hot water into a cup (discarding that) and pulling the shot immediately after that – with the thermostat clearly indicating that the heating is on – gives a lot better results as to crema and taste than warmer temperatures. So I drain around 2 DL of water before making coffee. Without any particular wait in between. This is at around 400 meters above sea level.