What it's Really Like to Use a Single Boiler Espresso Machine

There are some enduring, albeit wrong and misguided, common misconceptions that single-boiler espresso machines are cheap, underperforming, and unable to produce café quality results. In reality, single-boilers are versatile and can fulfill the needs of many different home baristas. They’re compact and light on their feet, and sometimes, they punch above their weight in terms of performance. Ultimately, it’s the unknown that causes so much confusion over the single-boiler, so we want to show you what exactly living with a single-boiler is like, how to maximize its performance, and how to finesse and refine some barista skills to get the most out of these unheralded workhorses. We will demonstrate how you can make delicious espresso and milk-based drinks with the classic and ever-popular Rancilio Silvia  & our best-selling Eureka Mignon Silenzio grinder—to emphasize that you do not need to spend 10k on an espresso setup to get professional results at home. First, let’s get a quick refresher on the single boiler as a machine category. 

What is a Single Boiler?

Our How to Choose a Single-Boiler Espresso Machine blog discusses our machine lineup, how to choose one, and the pros and cons of each machine, making it an excellent resource for determining your needs based on your lifestyle. 

At their core, single boilers operate with one brew boiler to brew coffee and steam milk. Some single-boiler machines, like the ECM Puristika, only brew espresso, but most are going to have dual-ability. Because of this, single-boiler machines can fit on virtually any countertop in any space, giving you a complete café experience with a compact footprint. By extension, the compact size and less need for extra materials and mechanics keep the machines very simple and, thus, are less expensive than heat exchangers and dual-boilers. 

Who are single boilers for? 

• Beginners 
• Espresso purists
• Folks with a tight budget for a machine & grinder 
• Home baristas that require a small footprint

Some may say that single boilers are difficult to use and are confusing as opposed to heat exchangers and dual-boilers, which allow you to steam milk and brew coffee at the same time seamlessly. Yet, while most single boilers do not have a PID for things like temperature control or a dedicated boiler for steaming, they are actually straightforward to use if you develop a consistent workflow, have some essential pieces of equipment to aid you, and are eager to hone some technique that will guide you for the rest of your espresso journey. Here’s how to set yourself up for success. 

Consistency is Key 

Rule #1: The grinder is paramount. Pair your single boiler with a decent espresso-focused grinder. Learning to use and dial in your grinder is the biggest learning curve for properly brewing espresso, so we highly recommend using one like the Eureka Mignon Silenzio. It fits most home baristas' needs well. It has a small footprint, is in the mid-range of pricing, and produces fluffy and consistent grounds. Almost all positive and negative espresso outcomes start and end with the quality of the grinder you’re using, so this first step is critical. 

Rule #2: Use a scale. It cannot be stated enough that using a scale to measure your espresso input, output, and extraction time is the next most important consistency tool. It will help you troubleshoot issues much faster and create and easily alter an espresso recipe to guide you. Do you need to use a scale for every single shot? Once you’re dialed in, no. But measuring how much coffee goes into your portafilter is a key step toward consistency. Keep a shot journal to log and keep track of your results and findings. 

Rule #3: Try aftermarket products like precision baskets and shower screens. While lower on this list of importance, making small changes like using a VST or IMS basket can improve your shot consistency. Often, the OEM baskets that come with the espresso machines are roughly stamped sheet metal, and many of the holes are uneven. On the other hand, precision baskets are laser cut and have precise geometry, leading to better-tasting espresso. Lastly, a tightly fitting tamper like a 58.3, 58.5, or 58.55 size will help eliminate tamping errors and give you a better end-to-end level coffee bed. 

Best Method for Temperature Surfing for Single Boilers without a PID

Without a PID, there’s no visual way to know what temperature your brew water is. Ideally, we want the brewing temperature to be between 194F and 204F. This is why temperature surfing is necessary on single boiler machines, and it’s very easy to perform. Temperature surfing is essentially prematurely cooling the boiler down when the heating element is at its highest limit in brew mode. To do this, we must: 

• Pull your shot first for the most temperature consistency. 
• Preheat your mug using the water from the group head purge. Keep the portafilter in the group head.
• Press the brew button and purge water until the heating element indicator illuminates.
• Once the light is on, it’s at the high limit temperature—too hot for brewing.
• Wait 30-45 seconds after the light goes out, and you’ll be around 204F. Wait a few more seconds if you want a lower brew temperature. 
• Repeat this process if you’re pulling another shot. 

To recap, when In brew mode, after purging water, we wait until the heating light turns off. Then, wait 30-45 seconds from the boiler’s peak temperature to come down, and we’re ready to brew. There typically is a 15-degree temperature variance in non-PID single boiler machines, so you may be at 185F or 211F if you skip this step, leading to overly sour or bitter flavors in the cup. 

Steaming More Consistently on a Single Boiler 

Steaming is usually considered a weak point for single boiler machines because they lack dedicated steam boilers, but is this fully true? Sure, you cannot make more than one milk drink at a time, but you can surely make one milk beverage perfectly, with ease. A dedicated steam boiler is nice because you can steam on demand instead of waiting and have more power and capacity for steam. Steaming on single boiler machines can still be a pleasurable experience, and it can give you a perfect microfoam and allow you to pour barista-level latte art. In reality, steaming milk on a single boiler just takes a bit more time to get to the temperature needed, so if you can handle steaming a milk drink in 30-45 seconds vs 15 seconds, you’ll be completely fine. Here are some tips: 

• Immediately after you pull your shot, switch into steam mode and ready your milk steaming pitcher to purge water from the steam wand.
• For the driest steam possible, purge some water into an empty milk pitcher  until steam forms. Once the heating light goes dark, you are at optimal steaming temperature.
• Prep your milk pitcher with milk and steam. 
• Submerge your steam tip into the milk using the steam wand as a guide, move the pitcher down the wand a bit to partially expose the steam tip on the surface of the milk and tilt the pitcher slightly to encourage a whirlpool. 
• Introduce air for a few seconds and then submerge the steam tip below the surface of the milk to heat it to completion.
• Purge and wipe the steam wand.
• Pour your beverage.