I want to make my own brewing spoon. Can I use myrtlewood for a stirring spoon for beer? Will it change the flavor of the beer?
I can't answer as to how myrtlewood would affect the beer, but I do want to mention that it's generally not a good idea to let anything made of wood touch your wort or beer after the boil because the porous wood can harbor all kinds of microbes.
Around the 15th century, some of the brewing monks started to catch on to the way the angels (yeasts) were working. They found that if they used the same wooden spoon to stir their cooled wort, the same good spirit resulted. This technique was also used by the latter day Vikings, but they used oak staves carved with runes. The reason why these tools worked their miracles was that yeast fermentation cultures would live in the wood. Even when the spoon or rune was dried, the yeast culture could live dormant in the wood until the next use.