ScottLush Senior Member Joined: 25 Jul 2010 Posts: 4 Location: Boston MA Expertise: I live coffee
Posted Thu Nov 15, 2012, 5:54am Subject: Re: Egg shells for a smoother cup
Remember how Tums is 100% Calcium? That calcium combats heart burn? I think that's what's going on: bitter coffee like what used to come from boiling grinds with water or from a percolator was acidic and bitter. Calcium from the egg shells is a base that buffers the acid in the coffee. Reduces the acidity an otherwise acidic cup a smoother taste.
Gives it a good chicken taste (just kidding)
I've spoken with a bunch of coffee drinkers who used egg shells to smooth their brew in the 1950's and before, and I've tried it too but it didn't help (I was using good coffee that wasn't acidic). If our coffee is acidic (i.e. Folger's, Chock Full of Nuts, inexpensive store brands) egg shells might help. Now if only Keurig would add egg shells to their K-Cups it might improve the taste ;-)
Posted Thu Nov 15, 2012, 8:57am Subject: Re: Egg shells for a smoother cup
ScottLush Said:
Remember how Tums is 100% Calcium? That calcium combats heart burn? I think that's what's going on: bitter coffee like what used to come from boiling grinds with water or from a percolator was acidic and bitter. Calcium from the egg shells is a base that buffers the acid in the coffee. Reduces the acidity an otherwise acidic cup a smoother taste.
Gives it a good chicken taste (just kidding)
I've spoken with a bunch of coffee drinkers who used egg shells to smooth their brew in the 1950's and before, and I've tried it too but it didn't help (I was using good coffee that wasn't acidic). If our coffee is acidic (i.e. Folger's, Chock Full of Nuts, inexpensive store brands) egg shells might help. Now if only Keurig would add egg shells to their K-Cups it might improve the taste ;-)
On a variant of this I have perceived changes in taste of good, well-brewed coffee by adding eggshells - but ONLY if the coffee was brewed with distilled or RO water (water with <5ppm hardness and TDS). Coffee brewed with distilled water tastes harsh, at times acidic, sometimes perceived as bitter but more like sour. Harsh is the best way to describe it. It is similar to but not exactly like over-extraction.
The interesting thing is that if you brew coffee with distilled at double strength, then use hard water to dilute - you get the same taste results (a tempering of the harshness). Brew with distilled water and eggshells in the grounds, or add crushed eggshells later to coffee brewed with distilled water - it doesn't seem to matter. I think this does support the "antacid" hypothesis.
I also checked brewing extraction with varying the water hardness - using immersion method there is essentially no discernible effect. Now, if I was using maybe an auto drip, and the distilled water causes changes to percolation rates (a very likely scenario) I can see where soft water could change the overall extraction. But the tribal knowledge that "distilled water causes overextraction" is an invalid extrapolation that does not apply to all brewing methods.
I concluded that some calcium is needed during brewing coffee to temper the flavor profile. Much like brewing beer or fermenting wine, the calcium helps control pH - in alcohol fermentation, it controls it to have the proper balance of pH to support yeast growth.
------------------------------------------ ----------------------------------------- Le café doit être noir comme le diable, chaud comme l'enfer, pur comme un ange, et doux comme l'amour.
"There is no right answer with coffee. There is only the elixir in your cup at the moment you partake."
"...I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind;..." - Lord Kelvin RECIPES thread => http://www.coffeegeek.com/forums/coffee/machines/585708
Symbols: = New Posts since your last visit = No New Posts since last visit = Newest post
Forum Rules: No profanity, illegal acts or personal attacks will be tolerated in these discussion boards. No commercial posting of any nature will be tolerated; only private sales by private individuals, in the "Buy and Sell" forum. No cross posting allowed - do not post your topic to more than one forum, nor repost a topic to the same forum. Who Can Read The Forum? Anyone can read posts in these discussion boards. Who Can Post New Topics? Any registered CoffeeGeek member can post new topics. Who Can Post Replies? Any registered CoffeeGeek member can post replies. Can Photos be posted? Anyone can post photos in their new topics or replies. Who can change or delete posts? Any CoffeeGeek member can edit their own posts. Only moderators can delete posts. Probationary Period: If you are a new signup for CoffeeGeek, you cannot promote, endorse, criticise or otherwise post an unsolicited endorsement for any company, product or service in your first five postings.