For whatever it's worth, I think shellac has an undeserved bad reputation. I always heard it would turn white if moisture came in contact with it and would break down if alcohol touched it. These things would happen if someone left a cocktail glass sitting on a piece of furniture for instance. So I decided to test this and see for myself.
I finished some scrap pieces with several layers of shop-made shellac. I left half empty beer cans and drinking glasses sitting on the pieces. They never made the proverbial white ring on the test pieces.
Since these tests never had an effect, I decided to throw the pieces in my slack tub of water, which sits out in the sun by my shop. I was surprised to find that after being in the water and sun for a week or more, the shellac finish stayed intact and didn't turn white. I simply left the pieces floating in the water. It was at least 3 weeks, maybe a month before the finish failed. It never did turn white, but rather flaked away and disappeared.
An old salt once told me that they used to shellac the woodwork on their boats. I had my doubts until I did these tests.
I have several pieces of furniture here in my house that I finished with shellac. My wife sets a hot coffee mug on one of them every morning and it has yet to have any effect at all. Just sayin'.