Is the German Beer Purity Law still in effect?

Rein…what? you might ask. Reinheitsgebot literally means ”purity order”. 

We like to call it "German Beer Purity Law" in English and it refers to a series of regulations limiting the ingredients in German beer to ultimately end up in ones German beer stein and what is served at the Munich Oktoberfest.

The most historic version that goes back as far as 1516 was adopted as law in Bavaria. Similar laws existed in other predecessor geographic states of Germany.

According to the 1516 Bavarian law, the only ingredients that could and should be used in the production of beer were water, hops and barley. That’s it.  Just add a German beer stein or ceramic tankard and one is set to go.

Brewing Time Reinheitsgebot German Beer Stein .9L Lidded

Why was it created?

Two reasons (and a half):

First to prevent price escalation and competition with bakers of rye and wheat. This ensured that bread was kept affordable (since rye and wheat were only to be used by bakers).

Second, it was a protectionist law to defend Bavarian Beers from the increasingly popular Northern Germany rivals (that used additives). This actually led to the extinction of many varieties of Northern beers, such as cherry and spiced beer among others. This is also why lighter beers are prevalent at Oktoberfest.

The half reason is religious conservatism. It has been argued that religious beliefs played a role in the ban of plants normally used in pagan rituals. Gruit was the most popular herb mixture connected with pagan rituals (it was also very popular before hops started to be extensively used).

Has it changed ever?

Yes. The 1516 Bavarian Law saw revisions a few decades after being issued. Coriander, Bay Leafs and Wheat were allowed in the mid-1500’s, and more modern versions saw yeast added to the list. 
More recently, late last year, Bavarian Breweries voted in favor of a revision to the beer laws to allow for other natural ingredients to be used.  These laws have an affect on what is served in the iconic stoneware beer steins at the world famous Munich Oktoberfest.
In 1987, French brewers took the matter to the European Court of Justice that found that the Reinheitsgebot was protectionist and in violation of Article 30 of the Treaty of Rome. This ruling concerned only imported beer, so Germany chose to continue to apply the law to beer brewed in Germany which could be enjoyed from tankard German beer steins.
Some breweries in areas outside of Germany, such as Gordon Biersch in California and Namibia Breweries also claim to be compliant to the Reinheitsgebot allowing beer connoisseurs to put on a German wool hat and enjoy their pure brew in an authentic German beer stein.
To the Germanophile in you, here is the text of the original 1516 Bavarian Law (as translated on Karl J. Eden in his book “History of German Brewing”):
We hereby proclaim and decree, by Authority of our Province, that henceforth in the Duchy of Bavaria, in the country as well as in the cities and marketplaces, the following rules apply to the sale of beer:
From Michaelmas to Georgi, the price for one Mass [Bavarian Liter 1,069] or one Kopf [bowl-shaped container for fluids, not quite one Mass], is not to exceed one Pfennig Munich value, and
From Georgi to Michaelmas, the Mass shall not be sold for more than two Pfennig of the same value, the Kopf not more than three Heller [Heller usually one-half Pfennig].
If this not be adhered to, the punishment stated below shall be administered.
Should any person brew, or otherwise have, other beer than March beer, it is not to be sold any higher than one Pfennig per Mass.
Furthermore, we wish to emphasize that in future in all cities, market-towns and in the country, the only ingredients used for the brewing of beer must be Barley, Hops and Water. Whosoever knowingly disregards or transgresses upon this ordinance, shall be punished by the Court authorities' confiscating such barrels of beer, without fail.
Should, however, an innkeeper in the country, city or market-towns buy two or three pails of beer (containing 60 Mass) and sell it again to the common peasantry, he alone shall be permitted to charge one Heller more for the Mass or the Kopf, than mentioned above.  
Furthermore, should there arise a scarcity and subsequent price increase of the barley (also considering that the times of harvest differ, due to location), WE, the Bavarian Duchy, shall have the right to order curtailments for the good of all concerned.
 

Our Brewing Time Reinheitsgebot German Beer Steins available with lid and without