Aspartame in diet sodas will naturally break down over time, especially if stored in higher temperatures, and in both diet and regular sodas the carbon dioxide will produce further carbonic acid (incidentally making itself fl at), but aside from a change in fl avour①fl avour英 [?fl e?v?(r)] 美 [?fl ev?]n.風(fēng)味，情趣； 味，滋味； 香味，氣味vt.給……添風(fēng)味[添情趣，添風(fēng)趣]；給……增加香氣； 給……調(diào)味, the beverage is likely to be completely safe to drink— and will probably still taste good.

It would take a very, very long time for the flavour to be affected enough to be completely unacceptable —and even then it would still be safe.

Even if all of the remaining carbon dioxide has broken down into sour acid (which would take years in an unopened can), it's still far more dilute②dilute 英 [da??lu:t] 美 [da??lut, d?-]vt.稀釋，沖淡； adj.稀釋的，沖淡的and less acidic than your stomach acid, assuming you can handle the terrible fl avour.

Soda is usually consumed well before this becomes a problem,of course.

汽水中的天冬甜素會(huì)隨著時(shí)間自然削弱，尤其是被儲(chǔ)存在高溫條件下的時(shí)候，無(wú)論是飲用汽水還是普通蘇打水中，二氧化碳都會(huì)產(chǎn)生更多的碳酸（可能會(huì)使它變癟），但是除了味道上有所變化，飲料還是完全可以放心飲用的——而且味道可能依然很好。

讓味道變得完全不可接受需要很長(zhǎng)，很長(zhǎng)的時(shí)間——但即使到那時(shí)汽水還是可以被放心飲用的。

就算所有剩下的二氧化碳都弱化成酸（在沒(méi)打開的罐子里應(yīng)該需要好幾年的時(shí)間），和你的胃酸相比它還是更淡的，沒(méi)有那么酸，只要你能忍受它糟糕的味道的話。

當(dāng)然，在這成為一個(gè)問(wèn)題之前，汽水一般已經(jīng)被賣得差不多了。

One caution should be made: any sodas that contain real fruit juice, like orange soda, grape soda, etc., should be viewed as③be viewed as 被看作是potentially unsafe after their expiration. They can mould or ferment rapidly once the container is opened, in the case of aluminum cans, and glass or plastic bottles which have less perfect seals should be viewed as unsafe even before opening.

PS: The date on the packaging is the "Optimum Taste Date." This is the date by which companies recommend you to consume the beverage in order to enjoy the optimum taste.

值得注意的是：任何含有純果汁的碳酸飲料，比如橙子味汽水、葡萄味汽水等，過(guò)期之后都被認(rèn)為是無(wú)法安全飲用的。一旦密閉容器被打開，它們可能會(huì)很快地發(fā)霉或者發(fā)酵，鋁罐、玻璃或者塑料罐都可能密封得沒(méi)有那么好，甚至往往在被打開之前就是不安全的。

另：包裝上的日期是“最佳飲用期”。這是食品公司的建議，為了品嘗到最佳的味道，最好在這個(gè)日期之前喝完飲料。