During the 20th century, sake-brewing technology advanced. The government opened the sake-brewing research institute in 1904, and in 1907 the first government-run sake-tasting competition was held. Yeast strains specifically selected for their brewing properties were isolated and enamel-coated steel tanks arrived. The government started hailing the use of enamel tanks as easy to clean, lasting forever, and being devoid of bacterial problems. (The government considered wooden barrels to be unhygienic because of the potential bacteria living in the wood.) Although these things are true, the government also wanted more tax money from breweries, as using wooden barrels means that a significant amount of sake is lost to evaporation (approximately 3%), which could have otherwise been taxed. This was the end of the wooden-barrel age of sake and the use of wooden barrels in brewing was completely eliminated.