How much caffeine is in leftover coffee grinds after brewing?

I feel like I’m wasting coffee when I brew liquid coffee then throw out the remaining coffee grinds. (This is bad for an ADHDer!) Coffee is very edible as-is. You can just chew/swallow raw beans like any solid food, or grind them and put them in something to make them taste better or hit the stomach less hard like a milk/banana smoothie. Is there something special about brewing grinds that extracts most of the caffeine, or is there plenty of caffeine left in the remaining grinds after brewing? I wonder if society tells us to brew coffee just to sell coffee-brewers, or maybe we just need something to do in the morning…
Thanks as always for your help!!

That seems like semi-useless information without knowing how much the coffee had before being used.
If it had 5-10mg/g, it might be worth trying to extract the rest of it. OTOH, if the coffee beans start out with 100-200mg/g, most people would probably wouldn’t consider trying trying something like eating or rebrewing the grounds to get such a small percentage of the remaining caffeine out.

If you’re fiending for caffeine that bad, you can pick up caffeine pills pretty cheap.

There are chocolate covered coffee beans available for snacking. These are quite good, and perfect for those times when a hot cuppa ain’t happening.

The rule for brewing coffee is that you want to extract all the stuff that tastes good and leave behind the stuff that tastes bad. This leads to some precision needed in the extraction process. Temperatures, size of grounds, roasting profile and more. Trying to extract all the caffeine will pretty much guarantee that you extract all the bad tastes as well. If all you want is caffeine, buy the cheapest instant you can find. Percolated coffee extracts the most from the beans. There little left when done. Tastes as you expect.

squish, do you have a garden? Coffee grounds are good for certain plants, and can be used to kill off grass…

FYI … the chopped up beans are called “grounds” or “coffee grounds”, not “grinds”.

How many days do you reuse the grounds for? If all you want is caffeine you can make an acceptable pot of coffee 2 or 3 times with the same grounds. The color and flavor will suck, as **Francis Vaughan **just said. But you can get a buzz off it if that’s all you want.

Here’s the best I can work it out:

A brewed cup of coffee is typically 100-120 mg or so of caffeine, though it does vary based on brewing method and the type of coffee itself. I suppose something like 80-160 mg might be a better range.

10 grams of grounds is considered the standard for a cup of coffee, though I know that people vary that wildly in actual practice. So I suppose that means you get about 2/3 of the caffeine out in the first go (10 grams of grounds being 100-120 mg in the coffee and 40-80 left in the grounds).

By way of comparison, decaf must have 97% of the caffeine removed, thus only about 3-5 mg per cup.

So used regular grounds have a 1/3 the caffeine of fresh, but still 10x or more than decaf.

For the OP, all of this tells me:

  1. you get most of the caffeine in your cup using any brewing method. You’re probably not throwing out as much as you think you are.
  2. brewing longer extracts more caffeine, perhaps even twice as much, which is probably a better flavor-to-caffeine compromise.

All very useful, thanks!! I thought I was throwing out half the caffeine.
(I might have gone the rest of my life saying “grinds” instead of “grounds”)

You could do a solvent extraction – caffeine is very soluble in toluene, for example.

Don’t drink toluene, btw.

I was just going to post a question about this today because I have a bag full of these that I just bought. I was wondering how much caffeine there is in whole espresso-roasted coffee beans. I imagine eating whole beans is a pretty effective caffeine delivery system.

6 mg per bean (average).

Or you could do a supercritical fluid extraction with CO2. That’s the way the pros do it.