Today, Google announced a change to its search algorithm that the company says will impact 35% of Web searches. The change builds on top of its previous “Caffeine” update in order to deliver more up-to-date and relevant search results, specifically those in areas where freshness matters. This includes things like recent events, hot topics, current reviews and breaking news items.

Google says that the new algorithm knows that different types of searches have different freshness needs, and weighs them accordingly. For example, a search for a favorite recipe posted a few years ago may still be popular enough to rank highly, but searches for an unfolding news story or the latest review of the iPhone 4S should bring the newer, fresher content first, followed by older results.

For searches about recent events and news, Google may now show search results towards the top of the page that are only minutes old, the company says. For regularly occurring events, like the Presidential election, the Oscars, a football game, company earnings, etc., Google knows that you’re likely interested in the most recent event, even if you don’t specify keywords indicating that.

That means a search for “Apple earnings” won’t (in theory) require you to also type in “Q4 2011” in order to see the latest information. It will be implied that you meant this latest quarter, without the need for the extra text. Of course, Google was already ranking news items and stock symbols at the top of the page when users performed financial-related searches or searches for current information, but this algorithm change has an impact on the organic search results, too, not those from the verticals (search, finance, images, etc.) which have been integrated into Google’s Universal search.

For items that see regular updates, like consumer electronics reviews, reviews of a particular kind of car and more, Google will also feature the most current and up-to-date information above the rest.

This “freshness update,” is an extension of what Google begin last year with Caffeine, an under-the-hood improvement that, among other things, helped Google index content quicker, so results were more realtime. This year, Google also brought out its Panda update, which was meant to decrease the rankings of so-called “content farms” – SEO-optimized entities that critics said filled Google with low-quality results.

Now, it’s clear that Google understands that the most relevant search result is more often the one that’s relevant now – the one that’s bringing you new information. The update’s impact on Google Search is fairly substantial, with Google claiming that roughly 35% of search results will be affected by the changes.

Google used to have a search vertical specifically for the most recent updates at www.google.com/realtime, where it was indexing Twitter updates. However, when the contract with Twitter expired, Google shuttered the site (it now redirects to the Google homepage). Google said at the time that it planned to re-open the site with Google+ search results alongside other realtime sources of information. But with the new Google search update, a specific vertical for realtime information feels less necessary.