Liquid Template Variables - cookies
From Spiffy Stores Knowledge Base
The liquid template variable cookies has the following attributes:
cookies.name
You can access any cookie by name.
For example, if you have created a cookie called theme, then its value can be accessed by
cookies.theme
Note that the Liquid variable, cookies, only provides read-only access to the cookies.
You will need to use another method, such as JavaScript to create and update cookies.
Most themes include the Mootools Javascript framework, and this includes standard methods for creating cookies.
The following code creates a theme cookie with the value blue. This code can be included in the body of your page as required.
<script type="text/javascript">Cookie.write('theme', 'blue', {duration: 14, path: '/'});</script>