A food-grade lubricant, Petrol-Gel, called "Petrogel" for short, is a white colored gel. Petrogel is odorless, and is absolutely tasteless. Petrogel is made of USP mineral oil and other USP ingredients. Petro Gel lubricant has a very high melting point, which makes it extremely well suited to espresso machines, and notably, the group-gaskets of the machines.
Petrogel will not contaminate when in contact with food products and it's impervious to water - another reason that it's well suited to espresso machines. Petrogel lubricant is ideally used for valves, pistons, gaskets, sanitary pumps, slide mechanisms, all interior parts of freezer barrels, and espresso machines, where temperatures can vary widely, and where there may be some contact with food products.
We carry Petrogel in 4 oz. tubes. Because it is not toxic, it's flavorless, it's impervious to water, and it can take very high temperatures, it's the lubricant that is ideal for espresso machine group gaskets. You should always use it on your group gaskets to maintain your machine, and to maximize its lifetime. It will allow you to make better seals, and it will make your gaskets last longer. See our article on Cleaning an Espresso Machine for more on this.