I have recently switched from using pre-ground coffee to grinding my own beans.

With the pre-ground, I used 1.5 tbsp per cup, however when i used the equivalent in beans (before grinding) the coffee was noticeably weaker. This makes sense to some degree, since the packing density of beans is lower than ground.

Is there an established ratio of beans-to-ground which I can use to accurately determine what volume of beans I need to grind to produce the same strength I had before?

Apart from the packing density, is there any other reason why the beans would be weaker than ground on a equal mass basis?

7 Answers 7


Here's an opportunity to start refining your brewing process.

Coffee brewers, including myself, tend to use weight as our measuring unit as opposed to volume since bean sizes vary significantly already without accounting for origin or roast level. All of these factors will change the real amount of coffee you believe you have once ground and also change the extraction parameters needed to make a cup of coffee of the 'same strength'.

From what it sounds, I doubt that the beans you use are of the same variety as the pre-ground coffee you used to use. Not all coffee will taste the same nor brew the same, and the best way to track and refine your brewing to your taste is to measure accurately your bean (origin/blend, roast level, weight used, grind size), water (to coffee ratio, temperature, purity), and extraction time. Depending on what brewing method you use there may be more parameters you will have to account for but ultimately the aforementioned factors will always play a role in any form of coffee brewing.

Start by weighing an amount of pre-ground coffee that you used previously to find out how much coffee you used exactly and start by grinding that much of your new beans to brew.

Good luck!

  • I'm sorry to nitpick but you're measuring weight, not mass. You're right however, weight is a much more reliable way to measure coffee since void ratios can be all over the place depending on how fine you grind the coffee and what type of grinder you use.
    – PJNoes
    Nov 15, 2016 at 17:31
  • @PJNoes Thanks. You're right. I've amended the answer.
    – Shiri
    Nov 16, 2016 at 9:26
  • 1
    As this answer goes nerdy, should we drink six times stronger coffee on the surface of the Moon? I think, we can safely continue to measure weight on Earth. Consequently, within acceptable error, assume it as equal to mass, then build up our brewing techniques on that. I've never seen a weightbridge that shows the unit as "kgf" because it measures weight. Also, people hardly use equal-armed-scales to actually measure mass by comparison...
    – MTSan
    Nov 16, 2016 at 11:45
  • Weight vs mass is irrelevant unless you are dealing with different gravity. As long as he's measuring here on Earth, only, he's measuring differences or similarities in both weight and mass. Nov 17, 2016 at 18:44
  • 1
    I would say you likely should drink approximately 6 times stronger coffee on the moon because by that point, you'll be very tired not only from training for space travel, but also from your long journey, and sleeping in an uncomfortable, upright, velcro bed.
    – xr280xr
    Oct 15, 2019 at 16:10

Based on my own experience, ground coffee or coffee beans are more or less have the same volume per gram.

The author also shares the same experience with me on his blog here with some experiment and a nice photo.

I assume, the difference in strength may be a result of different bean quality. The flavor of coffee beans depend on many factors that you can find in this discussion.


Could it be possible that your previous ground coffee was finer than how you grind your coffee now? Try a finer grind with your usual measurement, and see if you can improve the strength.


Tip 1: Measure the volume after grinding (again) so the change in packing density of grinding won't be a factor.

At a medium grind as suitable for a drip coffee maker (Baratza #20), I find the pre/post grind ratio is close to 1:1. At a finer grind as suitable for an AeroPress (Baratza #14), the ground coffee is significantly less dense. A finer grind makes a lower packing density.

Tip 2: Weigh the ground coffee and compare that to the weight of ground coffee that you used to use so the density variation between beans won't be a factor. (Reportedly, darker roasts are less dense than lighter roasts because roasting removes water.)

Tip 3: Then you can focus on adjusting the grinder. Grind size makes a big difference in the resulting taste. As @wearashirt noted, it sounds like you need a finer grind to get your desired results.

By doing a triangle test, I found that 1 adjustment step makes a reliably noticeable difference between grind #20 (my favorite) and #21 (second choice) using a Baratza Encore burr grinder. This grinder's adjustment goes from #0 to #40, and a +1 difference is too small to discern visually. First do side-by-side non-blind comparisons of grind sizes since that's faster than a triangle test.


A good rule of thumb is to follow a 1:15 ratio of coffee to water. So for every 1 gram of coffee, add 15 grams of water, which coverts to about 3 tablespoon of coffee for every 1 cup of water.

  • Do you have sources for this? Is this a restaurant standard?
    – Mayo
    Jul 26, 2016 at 14:20

Uh the top post is awesome. By the way, if you have define how is your ideal coffee taste is like you might find this compass helpful.

enter image description here


For french press figuring a 1 to 4 ratio of coffee to filtered water, a hand burr mill, and temp controlled kettle set for 200 degrees, I've found 7 tablespoons of ground coffee yields 28 ounces of joe...8 yields 32 ounces. I pour the coffee in my French press, add the hot water, wait four minutes, and plunge to pour every drop in a tumbler.

Seth Kolodny

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