We’ve heard concerns from customers on whether or not they should worry about trace amounts of lead or metal poisoning within their machines’ boilers and parts. So we’re going to break down the makeup of particular metals that are housed within your unit to ease your mind — and your fears of caffeine withdrawal.
Water corrosion is where it all begins and understanding your machine and what conditions cause corrosion — oxygen, water, metal and a catalyst — will help you manage and maintain your espresso machine.
Used for some espresso machine boilers and stovetop espresso makers as it heats up the fastest, ‘aluminum is protected from corrosion by increasing the amount of naturally occurring aluminum oxide (Aluminum + Oxygen) on its surface.’
As a mixture of metals, also referred to as an alloy, and under ideal circumstances, Sergio Louissant of LatteMaestro.com explains that this combination protects the aluminum but also has a quicker turn around time in breaking down the aluminum oxide causing the aluminum to corrode.
Chloride in tap water wears down the catalyst that breaks the shield that is the oxide layer between the metal and boiler water, as stated in a piece in the JL Hufford Coffee Tea Supporter Forum. This causes damage to aluminum parts over time so it is best to use filtered water or to regularly clean and descale your machine to slow down the deterioration process.
However, even though machines with aluminum parts are less expensive, that doesn’t mean they’re frowned upon. With its ability to maintain good resistance against corrosion, it just may take more of a closer eye and knowledge to understand the chemistry of it’s maintenance and when its time to switch out parts to prevent the quick deterioration of this material. Because the connection between aluminum and degenerative diseases such as Alzheimer’s is still unclear, many folks try to avoid aluminum as a precaution.
Very resistant to corrosion, stainless steel can be found in Saeco, Nespresso and Capresso machines. But its downfall is being the life of the party when it comes to hosting bacteria for a longer period of time on its surface compared to any other metal.
However, bacteria aside, since you won’t be cutting, dicing or chopping any raw meat on or with stainless steel espresso machine boilers and parts, as long as you keep the stainless steel within your machine clean, this material is ideal for espresso machines as it provides excellent heat retention and assures rapid steam function.
Unlike stainless steel and aluminum, espresso machines that use copper/brass boilers and parts, such as Rocket, Rancilio, Quick Mill, Pasquini, LaPavoni and Francis Francis, not only act like a repellent to those grimy germs and retain heat longer, but they also are the most resistant to corrosion than any other metal.
However, even with it’s popularity in higher end machines, some users are still left worried about the lead content in brass boilers.
While lead is added to some brasses, most manufacturers plate brass with nickel, such as Rocket Espresso, preventing any lead from leaching into water, reducing corrosion and acting as a barrier between brass and water.
But taking extra care when it comes to lead in products, it was in October of 1999 that the California State Attorney General sued 13 key manufacturers and distributors over lead content, leading to the reduction of lead content to 1.5 percent from it’s original 2 to 3 percent in products sold within that state. Following this action manufacturers were asked to reduce lead or to follow the requirement to warn consumers about lead content even if it didn’t have the ability to leach into materials such as water.
Hopefully this trend will catch up to the rest of the 49 states in the U.S. but for now, whether you choose a machine with aluminum, stainless steel or brass, taking precaution is key but knowing how your machine works and what it reacts well with will also keep you happy, healthy and caffeinated.