Page titles displaying incorrectly in Google

I’ve checked my page source and titles are displaying correctly, as I have entered them on the create a post page:
http://stevethebartender.com.au/the-aviation-cocktail/
<title>How to make an Aviation Cocktail. Find more cocktail recipes online.</title>

Yet it displays differently in Google:
The Aviation – Steve The Bartender

All my posts are like this – is this something the Yoast plugin is doing?

https://wordpress.org/plugins/wordpress-seo/