A Q&A with Jeff Sosower, founder of Southern Cross Pottery

Established in 1987, Southern Cross Pottery has been making beautiful gravity-fed water purifiers for more than 30 years. We speak to founder and potter Jeff Sosower, who knows a thing or two about working with clay.

When did you first start working with clay?

I started working with clay when I was at university in Atlanta, Georgia, in the early ‘70s. I was enrolled in academic studies at Emory University, but I kept travelling to downtown Atlanta to Georgia Tech (equivalent to Australian TAFE). A friend of mine (who is now a professor of medicine) was interested in a computer course I had signed up to, which conflicted with a pottery course I wanted to take at Georgia Tech. He was unable to enrol himself as the course was booked out, so I let him take the course for me thinking that computers were not all that important! I can never remember when I did not have a keen interest in pottery. 

What was your initial vision for Southern Cross Pottery and has that changed over time?

Thirty years ago, when I first began working with clay, I was making mostly dinnerware and some decorative items. As time went on, the demand for quality Australian pottery diminished due to the huge importation of inexpensive Asian pottery. My wife is a registered nurse and very interested in alternative medicine; she thought that pure water would be a great avenue for me to explore through clay.

Where do you source your clay and stoneware?

The clay we use is a white high-fire porcelaneous stoneware which we source from Walker Ceramics in Melbourne. We use around 50 tonnes of clay a year. As it is a white clay body, it works extremely well with the 40 or so glaze combinations we have with our water purifier range.

How do the ceramic water purifiers work? What impurities are removed?

Water is placed in the top container (shaped like an inverted bell) which houses the ceramic filter. This container has a nozzle protruding through a small hole into the main body of the purifier, which filters the water effectively. The outer micro-porous ceramic wall screens the water down to one micron to remove up to 99.99 per cent of bacteria and suspended solids. The tiny pores of the ceramic make it extremely efficient at removing particulate matter and fine sediment. The ceramic is also a highly effective barrier to bacterial pathogens and water-borne cysts including e-coli, cryptosporidium, giardia and salmonella. The water passes through the filter’s inner core of activated charcoal which removes chlorine, ammonia, fluoride, bad tastes and odours.

Activated carbon works by attracting and holding certain chemicals as water passes through it; it is a highly porous material with an extremely high surface area for contaminant adsorption. (Adsorption is the phenomenon whereby molecules adhere to a surface with which they come into contact.)

The ceramic wall of this filter has been impregnated with silver ions to prevent the growth of bacteria in the filter itself and also in the stored water. The silver acts as a natural biocide inhibiting microbiological growth, meaning there is no need to sterilise the filter even when used over an extended period of time.

This design prevents any overflow problems common with two-part systems. Each purifier is handmade on the potter’s wheel and individually decorated in a variety of colours, many of which are uniquely Australian.
The purifier is fired to a stoneware temperature of 1305°C, making it the perfect non-toxic material to filter and store drinking water. Firing at this high temperature ensures the water purifier is waterproof and extremely resilient to cracking, crazing and chipping.

Unlike terracotta and earthenware systems, our stoneware system will not grow mould, become stained, deteriorate with age or leave a clay taste in the water. The inside of the purifier is glazed, allowing ease of cleaning.
No fumes are given off as with plastics or metals, allowing safer long storage. The insulating properties of stoneware will help keep your water naturally cool for drinking and ice may be added to the container for chilled water. There is no electricity or plumbing and the purifier is small enough that it can be moved easily from room to room.

What does a typical day look like for you?

I’m always busy. We manufacture the water purifiers from our factory in Coffs Harbour and we wholesale to well over 100 health food shops throughout Australia and overseas, as well as retailing through our showroom, which is attached to the pottery. With the popularity and increased speed and reliability of the internet over the past 10 years, more than half our sales are mail order. We attempt to complete 100 water purifiers a week and we try to have delivery in three to four weeks from when we receive the order.

What’s next for Southern Cross Pottery?

I am confident that the demand for water purifiers will only increase with time. I would like to continue making a quality all-Australian product at a reasonable price and over time develop new shapes and new and exciting glazes.