# Coffee faux pas: is it wrong to mix old and new grounds? **URL:** \ **Category:** In My Humble Opinion\ **Tags:** coffee\ **Created:** [April 21, 2007, 8:18pm UTC](https://boards.straightdope.com/t/coffee-faux-pas-is-it-wrong-to-mix-old-and-new-grounds/401100 "2007-04-21T20:18:50Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [April 21, 2007, 8:18pm UTC](https://boards.straightdope.com/t/coffee-faux-pas-is-it-wrong-to-mix-old-and-new-grounds/401100/1 "2007-04-21T20:18:50Z")
We have a drip coffee maker at work. When it’s time to make a new pot, I simply add a couple scoops to the old grounds (that are already in the filter). That way, the coffee maker is still able to extract some coffee molecules from the old grounds, in addition to the new. But then I was busted by our group’s Coffee Snob[sup]TM[/sup]. She was aghast that I wasn’t using a new filter and new grounds for each pot. I thought to myself, “This is just drip coffee, lady. If you’re that uptight about it, bring in a French press and make your own.” So what are your thoughts? Does anyone else do this? Or am I just a hopeless lowbrow? ---
**Author:** ![Pyper](https://avatars.discourse-cdn.com/v4/letter/p/5f9b8f/32.png) [@Pyper](https://boards.straightdope.com/u/Pyper)\ **Post date:** [April 21, 2007, 8:26pm UTC](https://boards.straightdope.com/t/coffee-faux-pas-is-it-wrong-to-mix-old-and-new-grounds/401100/2 "2007-04-21T20:26:04Z")
Erm, sounds kind of gross to me. When do you change the grounds and filter? When there is no more room? ---
**Author:** ![Alice\_The\_Goon](https://avatars.discourse-cdn.com/v4/letter/a/ed8c4c/32.png) [@Alice\_The\_Goon](https://boards.straightdope.com/u/Alice_The_Goon)\ **Post date:** [April 21, 2007, 8:33pm UTC](https://boards.straightdope.com/t/coffee-faux-pas-is-it-wrong-to-mix-old-and-new-grounds/401100/3 "2007-04-21T20:33:25Z")
Yeah, it sounds vaguely nasty to me. I want fresh grounds every time. ---
**Author:** ![DeadlyAccurate](https://avatars.discourse-cdn.com/v4/letter/d/ac91a4/32.png) [@DeadlyAccurate](https://boards.straightdope.com/u/DeadlyAccurate)\ **Post date:** [April 21, 2007, 8:33pm UTC](https://boards.straightdope.com/t/coffee-faux-pas-is-it-wrong-to-mix-old-and-new-grounds/401100/4 "2007-04-21T20:33:56Z")
Yes, it’s wrong, and anyone who does this should be beaten with old newspapers. ---
**Author:** ![WhyNot](https://avatars.discourse-cdn.com/v4/letter/w/c77e96/32.png) [@WhyNot](https://boards.straightdope.com/u/WhyNot)\ **Post date:** [April 21, 2007, 8:37pm UTC](https://boards.straightdope.com/t/coffee-faux-pas-is-it-wrong-to-mix-old-and-new-grounds/401100/5 "2007-04-21T20:37:11Z")
In most plant infusions, including coffee, the oils are extracted first, then the volitile (or essential) oils, which are actually alcohols, then the tannins then the bitter alkaloids. Whattsat mean? It means if you brew coffee too long or too slowly or try to get two pots out of one set of grounds, you’re going to get too-bitter coffee, even if you’re “freshening” the pot with some new grounds as well. Stop it. There are no “coffee molecules”, there are a hundred gajillion different chemical compounds in the coffee bean, and you only want some of them in your cup at the end. ---
**Author:** ![Caridwen](https://avatars.discourse-cdn.com/v4/letter/c/c89c15/32.png) [@Caridwen](https://boards.straightdope.com/u/Caridwen)\ **Post date:** [April 21, 2007, 9:23pm UTC](https://boards.straightdope.com/t/coffee-faux-pas-is-it-wrong-to-mix-old-and-new-grounds/401100/6 "2007-04-21T21:23:01Z")
Very nasty. ---
**Author:** ![Red\_Barchetta](https://avatars.discourse-cdn.com/v4/letter/r/da6949/32.png) [@Red\_Barchetta](https://boards.straightdope.com/u/Red_Barchetta)\ **Post date:** [April 21, 2007, 9:34pm UTC](https://boards.straightdope.com/t/coffee-faux-pas-is-it-wrong-to-mix-old-and-new-grounds/401100/7 "2007-04-21T21:34:26Z")
[QUOTE=Crafter\_Man] So what are your thoughts? Does anyone else do this? Or am I just a hopeless lowbrow? [/QUOTE] Sorry bud, but I think you know the answer now 🙂 ---
**Author:** ![Ravenman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ravenman/32/2929_2.png) [@Ravenman](https://boards.straightdope.com/u/Ravenman)\ **Post date:** [April 21, 2007, 9:38pm UTC](https://boards.straightdope.com/t/coffee-faux-pas-is-it-wrong-to-mix-old-and-new-grounds/401100/8 "2007-04-21T21:38:09Z")
It is wrong. Others aren’t demanding gourmet coffee, they expect coffee that isn’t prepared in a method perhaps favored by penny-pinchers, the lazy, or the near-indigent. ---
**Author:** ![Starving\_Artist](https://avatars.discourse-cdn.com/v4/letter/s/aeb1de/32.png) [@Starving\_Artist](https://boards.straightdope.com/u/Starving_Artist)\ **Post date:** [April 21, 2007, 9:46pm UTC](https://boards.straightdope.com/t/coffee-faux-pas-is-it-wrong-to-mix-old-and-new-grounds/401100/9 "2007-04-21T21:46:17Z")
[QUOTE=DeadlyAccurate] Yes, it’s wrong, and anyone who does this should be beaten with old newspapers. [/QUOTE] Anyone who does this should be eatin’ old newspapers. ---
**Author:** ![Red\_Barchetta](https://avatars.discourse-cdn.com/v4/letter/r/da6949/32.png) [@Red\_Barchetta](https://boards.straightdope.com/u/Red_Barchetta)\ **Post date:** [April 21, 2007, 9:48pm UTC](https://boards.straightdope.com/t/coffee-faux-pas-is-it-wrong-to-mix-old-and-new-grounds/401100/10 "2007-04-21T21:48:59Z")
[QUOTE=Starving Artist] Anyone who does this should be eatin’ old newspapers. [/QUOTE] Eating the old newspapers that they were beaten with. ---
**Author:** ![StuffLikeThatThere](https://avatars.discourse-cdn.com/v4/letter/s/bc8723/32.png) [@StuffLikeThatThere](https://boards.straightdope.com/u/StuffLikeThatThere)\ **Post date:** [April 21, 2007, 10:11pm UTC](https://boards.straightdope.com/t/coffee-faux-pas-is-it-wrong-to-mix-old-and-new-grounds/401100/11 "2007-04-21T22:11:19Z")
[QUOTE=Ravenman] It is wrong. Others aren’t demanding gourmet coffee, they expect coffee that isn’t prepared in **a method perhaps favored by penny-pinchers** , the lazy, or the near-indigent. [/QUOTE] Ahem. _blush_ We do this at our house. But we would never never never do this to a guest, or at work. I _swear_. We do weird stuff to ourselves to save a penny, but we don’t impose our weird stuff on other people. Honest. ---
**Author:** ![A.R.Cane](https://avatars.discourse-cdn.com/v4/letter/a/ee7513/32.png) [@A.R.Cane](https://boards.straightdope.com/u/A.R.Cane)\ **Post date:** [April 21, 2007, 10:27pm UTC](https://boards.straightdope.com/t/coffee-faux-pas-is-it-wrong-to-mix-old-and-new-grounds/401100/12 "2007-04-21T22:27:09Z")
The responses are interesting to me. This was a common practice during WWII and my parents certainly did it. Coffee was rationed and expensive when available. Surely there are some other older Dopers who remember this? ---
**Author:** ![dalej42](https://avatars.discourse-cdn.com/v4/letter/d/67e7ee/32.png) [@dalej42](https://boards.straightdope.com/u/dalej42)\ **Post date:** [April 21, 2007, 10:36pm UTC](https://boards.straightdope.com/t/coffee-faux-pas-is-it-wrong-to-mix-old-and-new-grounds/401100/13 "2007-04-21T22:36:14Z")
New filter, new grounds. If work is that cheap, I"m probably going to resign or bring my own coffee. I’d rather give up coffee than resort to that level of cheapness. ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [April 21, 2007, 10:42pm UTC](https://boards.straightdope.com/t/coffee-faux-pas-is-it-wrong-to-mix-old-and-new-grounds/401100/14 "2007-04-21T22:42:18Z")
O.K., consider me spanked! 😛 ---
**Author:** ![Zabali\_Clawbane](https://avatars.discourse-cdn.com/v4/letter/z/ecd19e/32.png) [@Zabali\_Clawbane](https://boards.straightdope.com/u/Zabali_Clawbane)\ **Post date:** [April 21, 2007, 10:45pm UTC](https://boards.straightdope.com/t/coffee-faux-pas-is-it-wrong-to-mix-old-and-new-grounds/401100/15 "2007-04-21T22:45:02Z")
I’m late coming into the thread, but I thought I should post that coffee grounds can ferment, so be careful if you are re-using them. They can also mold quickly in moist weather as well. Both of these reasons are why I don’t re-use coffee grounds. ---
**Author:** ![I\_Love\_Me\_Vol.I](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/i_love_me_vol.i/32/521_2.png) [@I\_Love\_Me\_Vol.I](https://boards.straightdope.com/u/I_Love_Me_Vol.I)\ **Post date:** [April 21, 2007, 11:01pm UTC](https://boards.straightdope.com/t/coffee-faux-pas-is-it-wrong-to-mix-old-and-new-grounds/401100/16 "2007-04-21T23:01:49Z")
[QUOTE=DeadlyAccurate] Yes, it’s wrong, and anyone who does this should be beaten with old newspapers. [/QUOTE] Ah, but you too are wrong! Anyone with even a _modicum_ of corporal-punishment comportment knows that you must always use fresh, _new_ newspapers for the beating. Never a mix of old and new papers or just old ones, for heaven’s sake! The essential oils in the vegetable-based inks dissipate within hours after a paper comes off the press. This lessens the amount of humiliating black smears on and about the coffee-offenders face and body. More importantly, the newsprint (paper stock) loses crispness and “body” very quickly once it comes off the giant rolls, runs through the press, and is collated and folded. Clearly both the “thwacking” sound (SO important for proper psychological debasement) and the ‘bite’ of the swat are less than satisfying if the newspaper is too old. DO NOT use a newspaper that has been trucked for miles out into the boonies or flown across the country (like the NY Times, for example). Make sure to use a local paper that you have bought off of a newsstand just after delivery. Don’t get caught up in journalistic integrity-- the _New York Times_ is clearly a better newspaper content-wise than your local _Bum Fuck Gazette_, but good heavens! THINK man! This is no time to lose focus— which paper is more _fresh?_ That is all that matters here. ---
**Author:** ![I\_Love\_Me\_Vol.I](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/i_love_me_vol.i/32/521_2.png) [@I\_Love\_Me\_Vol.I](https://boards.straightdope.com/u/I_Love_Me_Vol.I)\ **Post date:** [April 21, 2007, 11:04pm UTC](https://boards.straightdope.com/t/coffee-faux-pas-is-it-wrong-to-mix-old-and-new-grounds/401100/17 "2007-04-21T23:04:20Z")
[QUOTE=A.R. Cane] The responses are interesting to me. This was a common practice during WWII and my parents certainly did it. Coffee was rationed and expensive when available. Surely there are some other older Dopers who remember this? [/QUOTE] My mother talks about the privations of the depression and WWII sometimes. She recalls eating mustard and onion sandwiches. She speaks of this with more fondness than one would expect. ---
**Author:** ![sturmhauke](https://avatars.discourse-cdn.com/v4/letter/s/e47c2d/32.png) [@sturmhauke](https://boards.straightdope.com/u/sturmhauke)\ **Post date:** [April 21, 2007, 11:18pm UTC](https://boards.straightdope.com/t/coffee-faux-pas-is-it-wrong-to-mix-old-and-new-grounds/401100/18 "2007-04-21T23:18:11Z")
If you roll a newspaper up properly and then fold it in half, you get a pretty hard beating stick that lasts for a few strikes. ---
**Author:** ![GrrlGenius](https://avatars.discourse-cdn.com/v4/letter/g/7cd45c/32.png) [@GrrlGenius](https://boards.straightdope.com/u/GrrlGenius)\ **Post date:** [April 21, 2007, 11:22pm UTC](https://boards.straightdope.com/t/coffee-faux-pas-is-it-wrong-to-mix-old-and-new-grounds/401100/19 "2007-04-21T23:22:34Z")
Here in the deep south, I’ve seen coffee grounds in a filter mold overnight. I keep my beans in the freezer, and grind 'em each time, but once you’ve poured water into that filter, the grounds hold the water and the paper holds the water. You’re probably drinking a slew of unhealthy things, and probably mold amoung them. ---
**Author:** ![GrrlGenius](https://avatars.discourse-cdn.com/v4/letter/g/7cd45c/32.png) [@GrrlGenius](https://boards.straightdope.com/u/GrrlGenius)\ **Post date:** [April 21, 2007, 11:23pm UTC](https://boards.straightdope.com/t/coffee-faux-pas-is-it-wrong-to-mix-old-and-new-grounds/401100/20 "2007-04-21T23:23:43Z")
I meant to say in the deep HUMID south. [Next page](https://boards.straightdope.com/t/coffee-faux-pas-is-it-wrong-to-mix-old-and-new-grounds/401100.md?page=2)