The art of whisky glassmaking with Angels’ Share Glass

We caught up with Karen Somerville, Director and Designer at Angels’ Share Glass, to discover more about the fascinating process – and great skill – behind beautiful whisky glassware…

There are many different glass types, but the raw materials used in all are silica, soda ash and lime. Only fine silica sand is used in glass production to give it its clarity.

The makeup of the glass typically determines its use. Crystal, for example, used to have a heavy lead oxide content or metal compound. Soda lime glass melts quicker and is a softer glass, it is often used in mainstream glassware or for jewellery making. At Angels’ Share Glass, we use borosilicate, which is tough, strong and commonly known for use in the likes of Pyrex.

Whisky tumbler glasses – indeed all drinking glassware – tend to be a mix of soda lime glass and crystal. Any glasses with lead content cannot with stand high temperatures which means they are a) more delicate and b) more expensive to produce.

Glassblowers have many tricks and techniques, kept as closely guarded trade secrets. It’s a bit like chefs and their recipes! But the making process essentially falls into three phases:

Firstly, the glass is molten on a tube or punty. That means the glass is melted to 2000°C and the glassblower must continually turn it to form a ball of hot molten glass. The constant turning helps to defy gravity and stops the glass from dropping to the floor.

Next, the glass is blown into a precast mould. The moulds used to shape glass are generally made from stainless steel or brass. We also use a carbon graphite mould in some of our designs. Essentially, the precast moulds give the glass its form. If the glass were to be free blown (that is, not moulded), it would be spun out and tools such as grabs and mandrils would be used to form the drinking cup. As we use a mould, the cup is reheated to add the solid base to the bottom of the glass.

Finally, the whole glass has to be placed in an annealing kiln for about 12 to 14 hours. this allows the glass to reach and constant temperature Normally sits at 700 degrees and so it doesn’t cool to quickly and crack.

In terms of pre-production for a new whisky glass or drinks tumbler, you must start with a design concept. Sampling would then involve initial moulds… once a mould is cast, that’s it! If you wish to make changes, you must make a new mould, so the initial designing and sizing is key.

From then, you sample and produce and if the mould and design are what you want, you can start producing more of them. Once cast, a glass mould should last around three to five years.

It can generally take six to nine months to get a new glassware project off the production line. We deal with small runs, but many large glass manufacturers only deal in high volumes and the initial glass run could be around 20,000 units.

Quality testing and consumer feedback are the only tests we do. Any flaws or weaknesses are usually picked up in first sample prototype run and can be improved on fairly quickly.

The most exciting thing is when you see molten glass become “a thing” before your eyes. One minute you have a tube in your hands, the next you have a glass, or a dropper… or maybe even a unicorn! It is also the best feeling to see your glass on a shelf in a store.

I’d love to make large installations as well as practical pieces. We are a small studio, so our size does limit us to smaller products, but I’d love to be able to make larger pieces, like stills. Imagine making the inside of a whisky column still in glass to show what’s happening to the liquid inside!

Glassblowing is a skill and most certainly needs the human element. In terms of developing technology, we have seen glass 3D printers emerge. While these were printing very beautiful art spun pieces, I don’t think it’s a realistic alternative to the heart and soul of creating pure unique forms with your hands.

All our products are made by hand. It is the legacy we want to pass on to other glassmakers and we want to keep lampworking and Scottish glassmaking very much alive.