Developing a glaze is a bit like cooking, only when you first start out it’s like being thrown in a kitchen and told to cook an authentic Ethiopian dish with all the ingredients in Ethiopian. It can be pretty overwhelming knowing where to begin. Potash feldspar, whiting, silica, kaolin, nephaline syenite. What are they? What does each one do?
Slowly, slowly through testing and observation I’m getting to understand the possibilities of raw materials. It's often about working backwards, problem solving to determine why something came out of the kiln matt instead of satin or why the glaze crawled. Raw ingredients, firing temperature, clay body and thickness, application...there are so many things that can alter the outcome of a glaze.
I'm currently developing a black matt glaze using iron oxide and manganese dioxide as the main colourants. My teacher has always said you can never do enough testing – advice that rings true time and time again.
Glazing: It's best to test glazes that have toxic oxides for leaching – you can do this by filling the vessel with vinegar and leaving it for a few days, if the vinegar discolours the glaze it's not food safe (leaching is less likely to occur in high gloss finishes).
Glaze ingredients can be hazardous in their raw state making it essential to follow the appropriate safety procedures when mixing and applying glazes. All finely milled ingredients are a dust hazard and can be dangerous if airborne and inhaled. Apron, gloves and masks are a must when glazing!
Summer Veggie Salad
This rustic platter works well for a casual lunch feast. The satin black glaze is understated and works well for this thrown together salad. You can substitute any of the veggies for your favourites or whatever you have in the fridge.
1 cup cous cous
1 red onion sliced
1 bunch asparagus
1 punnet cherry tomatoes halved
1 can chickpeas (rinsed well)
2 tbsp good quality olive oil
1 bunch parsley roughly chopped
Put cous cous in a bowl, pour over boiling water and cover for a few minutes. Chop the asparagus spears in three and boil for a minute or two. Put red onion and olive oil in a frypan and soften. Use a fork to separate the cous cous and combine all ingredients. Season to taste and top with pan fried haloumi.