For back flush cleaning, insert a blind filter in a portafilter and add up to 1/2 tsp. of Cafiza powder. Insert the portafilter into the group head. Activate the brew cycle for ten seconds, stop for 10 seconds, and repeat this step 5 times. Remove the portafilter and activate the brew cycle. Rinse portafilter in the stream of water from the group head. Stop the cycle. Re-insert the portafilter and then start and stop the brew cycle in 10 second intervals, 5 times. Make and discard a cup of espresso to ensure no residue remains.
For soaking, place filters and metal parts of portafilters in a solution of 1 tsp. of Cafiza powder per 32 oz. of hot water. Soak for 30 minutes. Rinse clean with hot water.