Puyallup South Hill's RAM Restaurant and Brewery is enjoying its Sweet 16.

Or, at least, the brewery part of it is. The restaurant itself has actually been around for 18 years, but the Pierce County eatery is celebrating 16 years of on-site brewing in 2013.

That may not sound like much of an anniversary, but it makes a difference, if especially if you have a well-practiced palate for beverages. Store leader Jason Jones, who has been at the South Hill RAM since almost the beginning, remembers when the restaurant used to have its beer brewed in Salem, Ore., before it was shipped up and served to diners.

“It's a big deal,” said Jones. “We want to get it out there in the community that we brew fresh beer here every day. The beer here is nationally recognized, award-winning. We have gold medals in almost every one of our staple beers.

“If you're comparing to beers that are made elsewhere and then shipped here and kegged, there's a whole process it has to go through. Beer has a shelf life like anything else. One of the main ingredients of beer is yeast, and yeast can make beer change over time. Beer that's made fresh, you can tell.”

“Unlike some other alcoholic beverages, it tastes best when it's freshest,” added South Hill RAM brewer Rupert Cross. “As soon as it's done fermenting and transferred and ready to go, that's the best time for drinking it.”

Excessive exposure to light, heat and oxygen, Cross explained, degrades the flavor compounds in beer and causing various effects. Oxygen oxidizes the beer, resulting in a stale non-“brewery fresh” taste and aroma. Heat, likewise, contributes to oxidation (the warmer the beer, the faster it oxidizes). Exposure to sunlight and strong white light, on the other hand, causes a chemical reaction that gives beer the often-too-familiar “skunky” smell and flavor.

Oxidative reactions are always occurring in beer, regardless of the storage method.  Motion, in addition, accelerates the process, as with many other chemical reactions.

So what does oxidation do, exactly? Well, it depends on the beer. In lighter beers, for example, an unsaturated aldehyde compound forms. The compound, which has a flavor that brewers compare to paper or cardboard, has a very low flavor threshold, so even the tiniest fractional amount in a beer can be detected by taste buds. Dark beers, on the other hand, can be affacted by the degradation — or outright disappearance — of the taste of the malt, which can harm the full flavor of the drink.

Simply put, according to Cross, any precautions taken to account for oxidation are still inferior options to tasting the beer as close to its brewing as possible.

“It can be hard to explain, I think, so people should come try us and find out for themselves,” said Jones.