If you fancy yourself a wine drinker, then you know there’s no sadder sound than the “glug-glug” of a bottle being poured down the drain because it sat open for too long. While oxygen is great for “opening up” a wine when the cork is first removed, too much oxidation can lead to bland tasting glass or a vino that tastes like vinegar. While drinking a bottle that’s been open for a week certainly won’t make you sick or have any other adverse effects on your health, whether or not it’ll actually be enjoyable is a different question.

The second a cork is removed from a bottle, the wine inside immediately begins to interact with oxygen, bringing out aromas and flavors suppressed by time. However, too much of anything is never good. As the days go on and your open bottle receives more and more exposure to oxygen, you’ll find that the wine becomes less and less enjoyable.

When debating whether or not to drink that week-old bottle, there are few telltale signs to look out for that will let you know if the wine has spoiled. First and foremost, the wine’s color should be enough to alert you if something is amiss — spoiled reds will take on a rusty brown hue while past-due whites transform from lighter shades of yellow to gold or even opaque. If you’re not noticing any differences in color, certain aromas could also signify that your bottle has started to turn. Where fresh wines will have aromas of fruit cut with vibrant acidity, bottles beginning to sour will have sharper, more bitter, almost acetone-like smells. If the nose is enough to take you aback, it’s probably not a bottle worth drinking any longer — but again, it won’t physically harm you if you do.

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If you decide to throw all caution to the wind and take a sip anyway, you’ll likely notice a number of flavors that feel unbalanced. Oxidized wine typically carries nuttier notes with lackluster fruit undertones. For wines with higher alcohol contents like Shiraz or Zinfandel, you may notice that, after a few days, they taste much boozier than when first opened.

When it comes to choosing a wine that’ll last you through the week, plan on picking a bottle with higher levels of residual sugars or preservatives like sulfites — sorry, natural wine. For example, Riesling, with its higher levels of sugar, will stay fresh after opening for longer than wines like Grenache or Pinot Noir, which have fewer preservatives and thus spoil faster. In general, high-tannin, high-acid wines with a fair amount of sulfites will last the longest. If you’re worried your beloved bottle may spoil before you have a chance to finish it, there are a number of incredible boxed wines on the market that stay fresh for weeks.

No matter the bottle you choose, when storing leftover vino, always be sure to push the cork back in as far as possible or consider purchasing wine stoppers to reduce the amount of oxygen entering the bottle before storing it in your refrigerator (yes, even if it’s red). When you’re ready to enjoy the bottle again, remove it from your fridge before allowing it to rest on the counter for 30-40 minutes before uncorking. And remember: If it still tastes good to you, then it’s still good to enjoy!