We have a website with a searchable database of recipes. You can search the database using an online form with dropdown options for:

Course (starter, main, salad, etc)
Cooking Method (fry, bake, boil, steam, etc)
Preparation Time (Under 30 min, 30min to 1 hour, Over 1 hour)

Here are some examples of how URLs may look when searching for a recipe:

find-a-recipe.php?course=starter
find-a-recipe.php?course=main&preperation-time=30min+to+1+hour
find-a-recipe.php?cooking-method=fry&preperation-time=over+1+hour

There is also pagination of search results, so the URL could also have the variable "start", e.g.

find-a-recipe.php?course=salad&start=30

There can be any combination of these variables, meaning there are hundreds of possible search results URL variations.

This all works well on the site, however it gives multiple "Duplicate Page Title" and "Duplicate Page Content" errors when crawled by SEOmoz.

I've seached online and found several possible solutions for this, such as:

• Setting canonical tag
• Adding these URL variables to Google Webmasters to tell Google to ignore them
• Change the Title tag in the head dynamically based on what URL variables are present

However I am not sure which of these would be best.

As far as I can tell the canonical tag should be used when you have the same page available at two seperate URLs, but this isn't the case here as the search results are always different.

Adding these URL variables to Google webmasters won't fix the problem in other search engines, and will presumably continue to get these errors in our SEOmoz crawl reports.

Changing the title tag each time can lead to very long title tags, and it doesn't address the problem of duplicate page content.

I had hoped there would be a standard solution for problems like this, as I imagine others will have come across this before, but I cannot find the ideal solution.

Any help would be much appreciated.

Kind Regards