Are these coffee grounds okay for cold brew?
July 18, 2023 6:48 AM   Subscribe

Got a new bag of ground coffee and noticed it acting oddly when I made cold brew with it. I can't quite find a link that explains if this is a bad sign when using cold water.

I do this every few days with a cup of grounds and five cups of water soaked overnight. This is a new bag of vanilla-flavored store-brand ground coffee, which, yes, I know, not classy. When I poured in the water, it didn't float and form a dense mat as usual.

When I went to pour it, it had all sunk to the bottom instead of needing to be squeezed out hard by the French press. The cold brew is thin and lackluster, but nothing tastes actively bad about it. Is the caffeine all there? Or will I need to rely on the placebo effect until I can get more? I am assuming it is safe to drink because coffee has antiseptic properties, but let me know if I am wrong.

(I should probably get a grinder at this point, too --)
posted by Countess Elena to Food & Drink (8 answers total)
 
Best answer: This likely means that the coffee was old or otherwise not in great condition. When coffee is roasted if frees up carbon dioxide inside the beans. When we brew coffee this gas comes out which results in some foaming and formation of a "raft" of coffee grounds if you're doing an immersion technique. Over time the carbon dioxide comes out of the beans, so if you brew with beans that don't produce any foaming, etc. it is usually a good indication that the beans are stale and past their prime. Needless to say, when coffee is ground it increases the rate of degassing, which is among the reasons why ground coffee doesn't store as well as whole bean coffee (especially since who knows when your beg of coffee was actually roasted and ground). The caffeine, etc. is still in there, but it's no surprise that it tasted lackluster.
posted by slkinsey at 6:55 AM on July 18, 2023 [8 favorites]


Best answer: Yes, that's stale beans. Which is fine. It won't make you sick or anything. America loved stale coffee until like 1999. It's still caffeinated. But it also sounds like it's too finely ground for a french press, which makes it tough to press. You might want to pour it through a filter instead of pressing since having to force the french press tends to raise the risk of it all exploding out (not necessarily breaking the glass, but a coffee volcano).
posted by dis_integration at 6:58 AM on July 18, 2023 [2 favorites]


Best answer: Seconding that the coffee beans were older than you're used to, so sank. They likely didn't brew quite as strong due to sinking instead of floating. The caffeine will still be there, but may just be weaker (because the coffee itself is weaker, not because the caffeine disappeared). I wouldn't be shocked if companies use older beans to begin with for flavored coffee, since the flavor additives disguise the staleness. Definitely still safe to drink, though!
posted by csox at 7:00 AM on July 18, 2023


I use the cheapest beans in the cupboard for cold-brew, so don't worry too too much.

Coarser grounds are better for the screen in a French press pot, if you are grinding your own (or having the coffee shop grind them for you, or using the common machine at the store).

I read recently that the flavors come out of the grounds more at the beginning of the brewing but tail off, while caffeine comes out at a fairly constant rate. This suggests that the longer you brew, the more caffeine you extract -- but that the best flavors are extracted at the beginning of the brew. (Naturally, I left a French press pot of cold-brew on the counter for like 36 hours this weekend, so clearly I haven't yet internalized this lesson...)
posted by wenestvedt at 7:44 AM on July 18, 2023 [1 favorite]


slkinsey's answer is great. I occasionally make a large batch of cold brew, strain with a strainer, then again though a strainer with a coffee filter. Handling coffee grounds in volume is messy. They shouldn't really go down the drain. I compost them; the blueberry plants seem to be thriving.
posted by theora55 at 8:58 AM on July 18, 2023 [2 favorites]


It seems possible to me that the flavoring agent is coating the jagged and irregular grounds and making them less able to hold onto tiny bubbles of air at their surfaces.
posted by jamjam at 9:36 AM on July 18, 2023 [1 favorite]


Response by poster: Thanks, guys!
posted by Countess Elena at 7:45 PM on July 18, 2023


Response by poster: Addendum for anyone later looking for information: that stuff did not have enough caffeine to operate as usual. I had a groggy couple of days before I realized I needed to drink twice as much to get near the same effect. It's gone now!
posted by Countess Elena at 11:31 AM on July 21, 2023


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