Archimedes Challenge - simplest accurate method of calculating basket volume

#1: Post by **KarlSchneider** » July 13th, 2006, 9:08 pm

...split from A Tale of Two Levers by moderator...

espressoperson wrote:Funny how even though I never used the single Cremina basket in the 23 years I've had it I still miss it . But I'm sure we're all happy that Karl has it and will be able to continue his single basket single origin tales on two machines.

Michael,

I will post pics of the two Cremina's and the two Elektra's i have soon.

But tonight let me challenge the HB collective. Please suggest a method to measure the volume of baskets using tools found in a usual kitchen. I want to post a list of volumes of these four baskets. I do not have the tools of a lab. I will send to whoever describes the simplest accurate method a 49mm HB logo tamper (which you can also change to any size for a small cost from EspressoParts).

Archimedes started the world on the lever thread. He also figured out how to measure volumes of odd shaped things. I am asking for a new Archimedes principle for espresso basket volume measuring.

KS

#2: Post by **AndyS** » July 13th, 2006, 9:35 pm

KarlSchneider wrote: Please suggest a method to measure the volume of baskets using tools found in a usual kitchen.

Take a piece of saran wrap and work it into the basket with your fingers so that it smoothly lines the interior. Place on gram scale and bring indicator back to zero. Fill with water to the brim of basket. Weight in grams equals volume in ml.

If you don't have a gram scale, you could fill basket with water and pour it off into a measuring cup. Count how many baskets it takes to fill a one cup measure. One cup divided by number of baskets equals volume of one basket.

#3: Post by **another_jim** » July 13th, 2006, 10:24 pm

Andy beat me to it.

However, wrapping the outside may be a tad more accurate, since there won't be excess wrap, or air gaps taking up volume. If the wrap doesn't stick, you can make a flour/water paste (2 parts flour to 1 water) and paint it on the basket's underside before putting on the wrap -- it washes off.

And yes, every proper kitchen has a basting/eggwash brush

#4: Post by HB » July 13th, 2006, 10:39 pm

Why not measure with sugar and forget the plastic wrap? It's too coarse to pass through the holes and volume is volume, right?

#5: Post by **espressme** » July 13th, 2006, 10:51 pm

KarlSchneider wrote:Split from A Tale of Two Levers by moderator...
snip
Archimedes started the world on the lever thread. He also figured out how to measure volumes of odd shaped things. I am asking for a new Archimedes principle for espresso basket volume measuring.
KS

Were I trying, I would place a piece of clear shipping tape on the perforated bottom of each basket and fill with good quality water ( use a knife blade edge on the edge of the basket to coax/drain off the meniscus [ hump]) and then dump the filled basket into a container on a zero'd ( Tare) gram measuring kitchen scale. 1 gram H2O= 1cc.

Then one could also use a tablespoon/partial table spoon measures to fill the basket till it has a flat surface meniscus. You of course have done the knife edge bit to the measuring spoons.

Then you could also use a simple dry ingredient like baking soda and screed off the spoon measures. Then add the dumps into the basket till it is level. Volume is equal to wet measure.
Or.... do the same with butter or margarine.
But... you must assure that you know the country of origin of your tablespoons> They may be different measure! see below:

Thanks to "Online Conversions!" http://www.onlineconversion.com/volume.htm

1 Tablespoon [US] = 14.786 764 844 cubic centimeter. Again 1cc is = to 1 milliliter= 1 gram H2O

Or if you have a diabetic in the household use their calibrated syringe to fill the basket.

I'm looking forward to someone with way too much time on their hands finding sneakier methods

Best regards
Espressme

#6: Post by **mogogear** » July 14th, 2006, 12:49 am

I maybe too dumb for you gents, volume maybe the question, but a volume of what?-Since there is no space between particles of "water' you need to measure in the medium you wish to measure! Coffee. Work backwards I say!

So,

1.Fill said basket ( after putting empty basket on digital scale- TARE) with the coffee( since that is what you will be using seems like a "constant" to me).

2.Put said basket on scale( full of coffee)

3.Read scale

4.Write down number

5.Make shot

6.Drink shot

(leave out steps 3-6. You'll know what you want)

Send tamper to.......mo....please

#7: Post by **another_jim** » July 14th, 2006, 8:15 am

mogogear wrote:I maybe too dumb for you gents

So,

1.fill said basket ( after putting empty basket on digital scale- TARE) with the coffee( since that is what you will be using seems like a "constant" to me).

2.Put said basket on scale( full of coffee) ...

Um, the question is about volume. Do you happen to know the density of Karl's ground and tamped coffee?

#8: Post by **peacecup** » July 14th, 2006, 3:13 pm

Karl,

Clearly, what you want to measure is the volume of coffee (i.e. not sugar or water) that fits into your basket. You also want to know the volume of coffee that, properly ground, dosed, and tamped, will produce an excellent shot of espresso. Therefore I humbly suggest that you:

1. Grind, dose, tamp, and pull a shot that you consider excellent.
2. Replicate the grind, dose, tamp, as nearly as possible.
3. Gently remove the unbrewed coffee into a measuring utensil of choice.

I also suggest that you post the basket depth and diameter in mm.

My Ponte Vecchio has a 45-mm basket, and I'd like to compare volumes.

As usual, Karl has started a very important topic, because it gets at the heart of brewing with the lever machine - i.e. volume of water per volume of coffee. E.g., I have been brewing 1.5-2.0 oz doppios with my PV. I have yet to measure the volume of coffee, but I would like to know how it compares to the Elektra/Cremina. My doppios require three pulls on the PV, so my shots go though two periods of ambient pressure between pulls. As of late they have been tasting so great that I have abandoned my wish for a commercial lever machine.

PC

#9: Post by **espressoperson** » July 14th, 2006, 3:42 pm

HB wrote:Why not measure with sugar and forget the plastic wrap? It's too coarse to pass through the holes and volume is volume, right?

IMO Dan's solution is the sweetest and easiest. I tried the plastic wrap on the outside with water but it was too hard to ensure the water level was the same each time, and too easy to get water on the basket or the scale. The sugar just needs a sweep with a straight edge to get it right. (And since no one was home, the sugar can be reused).

Basket               Sugar (g)   Dif (g)   Dif (%)
New double           35.7         4.7       11.6
Original double      40.4         0.0        0.0
Elektra double       43.7         3.3        8.2

I'm not sure how to calculate percentage difference, but since the original basket is my standard I calculated the percentage with that as the reference.

No doubt a critical factor for espresso is how much coffee fits in the basket but IMO that is a different discussion that has complexities all its own. There is nothing wrong with this one measure of volume that gives us a repeatable standard for comparison across all baskets.

BTW, the Cremina baskets weighed 20.5 g and 24.1 g. The largest Elektra basket was 22.1 g which confirmed my feeling that it was thinner than the Cremina baskets.

July 15th, 2006, 6:08 pm

Many thanks to all who responded. As a university philosophy professor I have always chosen to give students a vague writing assignment rather than a precise one for which I already had my answer identified. The vague assignment always brings out better thinking than the channeled kind. While I really did not mean to be vague in this challenge I see that I was and am delighted to read and think about the solutions.

Let's start with my real question. I am intrigued by this photo:

I thought I would like to know the capacity of each just to compare. On the two straight sided double ones the problem seemed to be measuring the depth of each and using the simple equation for the volume of a cylinder (pi r squared h) and the diameter of 49 mm is already known. But the shape of the two singles was a challenge. Hence my question.

I tried AndyS's saran wrap without success. I thought the tape might work but had none.

I do have a scale with which I weigh my green and roasted beans so getting weight to a gram was possible. I liked the sugar suggestion. However I think Jim Schulman is right that we need to consider density in these calculations. I finally found on the web the measure of 0.83g/ml for sugar. I weighed a full basket of sugar in each kind and got the following:

Elektra Double holds 39g = 47ml
Cremina Double holds 33g = 39.75ml
Cremina Single 31g = 37.3ml
Elektra Single 27g = 32.5ml

BTW I measured the depth of the Doubles and got volumes of 46.2ml for the Elektra and 41.8ml for the Cremina. These differences are 2% and 5% which seems reasonable given my simple methods.

KS