Ozark_61 wrote:Perfect, that's what I was wondering. Now you have to wonder if you can increase that 22% to ? Oh.. yet another test - taste 22% vs. 60% etc! Zen espresso... how little grounds could one use to extract a double, young grasshopper?

Nescafe instant -- Percolate coffee in 20 foot silos (as opposed to 1/2 inch thick pucks), for 4 to 24 hours, and you can get up to 45% solids extraction; yum! The SCAA quotes 20% as the ideal for brewed coffee; Illy quotes 22.5% to 25% as ideal for espresso. Anything much higher than that requires hydrolizing and dissolving the cellulose in coffee. Since coffee has to be "100% natural," instant coffee is created by raising the coffee to water concentration in the columns even higher than espresso. This increases the acidity enough to accomplish the task. In order for this to work with Robusta, which is too low in acid normally, it has to be steamed while it is green. Double yum!

It may be Vietnamese Robusta getting what it deserves; but it seems cruel and unusual for even the most ignorant consumer.

Ozark_61 wrote:Also - my single baskets hold 14-15gms - should I expect similar results as with 14gm in a 18gm double basket?

Well Jim - that's not very appetizing now... ahh college days. Condensed milk, full glass of ice, and instant coffee - royalty! Still, with a 1/2" puck with 25 sec of 9 bar pressure, can we grind fine enough to get a good double to increase TDS without overextracting, or is over 22% etc overextraction de facto?

How about those 'single' baskets that hold 14-15gms? Do they qualify for 'everyone else's double', or do they lack the head space?

Geoff

k7qz wrote:Agreed. A 14 gram dose yields a wet puck for me here as well. The shot tastes great however and the only downside I've noticed is that the puck doesn't pop out of my PF cleanly as one neat unit but makes for more slop in my knockbox.

My new hundreth gram digital scale (I know, overkill- but I couldn't resist. Besides I can always use it for reloading or so I told my wife...) should be sitting on my doorstep tomorrow. Looking forward to playing with this a bit more!

I still use a good old fashioned beam scale good down to 1/10th of a grain, I have a couple of them on the loading bench. For those wondering, one ounce is 437.5 grains.

The scale I used for coffee is good down to 0.1g, digital touch screen and does 500 grams. I got it off eBay for around $25 including shipping.

Ozark_61 wrote:Well Jim - that's not very appetizing now... ahh college days. Condensed milk, full glass of ice, and instant coffee - royalty! Still, with a 1/2" puck with 25 sec of 9 bar pressure, can we grind fine enough to get a good double to increase TDS without overextracting, or is over 22% etc overextraction de facto?

How about those 'single' baskets that hold 14-15gms? Do they qualify for 'everyone else's double', or do they lack the head space?

Geoff

In my old work with the Mini and M3, the amount of extraction depended on the area of the filter in the basket divided by the height of the puck. According to that, a single basket loaded with 10 grams of coffee will taste just like a double loaded with 18 grams. With conical grinders, this relation doesn't seem to hold. Moreover, singles just taste different, even at the same extraction.

The shots during the Robur test are mostly running between 20% and 22.5% solids extractions. The differences do not correlate with taste (they are too small in any case), and I'm not getting a dramatic difference in the 13.5 and 16.5 doses except out of the M3, and somewhat the Lux. The taste of the shots seems properly extracted based on my older work, i.e. not dull tasting as in over-extracted or overly sour and bitter-sharp as in under-extracted.

DavidMLewis wrote:The ranges measured by Jim Schulman ran from about 17% to about 22%, more or less, with different grinders varying in how much the extraction changed with dose. The conicals seemed to change less than the planars. Even at something close to the extremes, 17% of 18 g = 3.1 g extracted solids, and 22% * 14 g = 3.1 g extracted solids. So even if you don't take into account the flatter extraction slope of the grinders Ken has been using, it's unlikely that the amount of caffeine in the lower-dose shot has gone up, and if you do it's quite likely that it's gone down.

Best,
David

I believe the key is time. Caffeine is water soluble, along with the majority of a coffee beans weight. If you are brewing 2 ounces of liquid out of a 12g dose, the water that passes through the coffee is the same volume and flow rate as that from a 18g dose. so the same or less caffeine should be extracted. Now if you soaked that 12g dose in 2 ounces of water for 10 minutes, then you would have much more caffeine extracted because of the prolonged exposure to water, provided the water is not super saturated and unable to dissolve anymore compounds.

That is why a press pot of coffee has more caffeine in it than a shot of espresso. The grounds have longer contact with the water and more caffeine is extracted. Or I could be completely wrong.

cannonfodder wrote:I believe the key is time. Caffeine is water soluble, along with the majority of a coffee beans weight. If you are brewing 2 ounces of liquid out of a 12g dose, the water that passes through the coffee is the same volume and flow rate as that from a 18g dose. so the same or less caffeine should be extracted. Now if you soaked that 12g dose in 2 ounces of water for 10 minutes, then you would have much more caffeine extracted because of the prolonged exposure to water, provided the water is not super saturated and unable to dissolve anymore compounds.

That is why a press pot of coffee has more caffeine in it than a shot of espresso. The grounds have longer contact with the water and more caffeine is extracted. Or I could be completely wrong.

I agree. Ceteris paribus, using less coffee should result in less caffeine being extracted. However, water temperature also plays a surprisingly large role in caffeine extraction. According to this source, caffeine solubility increases dramatically in hotter water:

The solubility of caffeine in water is 22 mg/ml at 25C, 180 mg/ml at 80C, and 670 mg/ml at 100C.

RapidCoffee wrote:As Goldilocks might say: 1g accuracy is too low, 0.01g is overkill, and 0.1g (roughly the weight of one bean) is just right. 0.1g precision digital scales are now priced so reasonably that every home barista can afford one. For example, the Triton T-2 scale (pictured on page 1 of this thread) has a capacity of 550gx0.1g, and is available on eBay for $20 shipped. If you prefer to tare the portafilter, you can find a 2kgx0.1g scale for as little as $40.

Here's a deal I just found on the internet; a 1000g x0.1g scale for $11 delivered, from Hong Kong. Or, using coupon code "BULKRATE" you can get 3 of them for $30.71, which will include a mandatory charge for registered mail.

http://www.dealextreme.com/details.dx/sku.1165

I have bought one item from this website before, and have had no problems with them. The website is owned by a guy who split off from a partner who had another website that operated out of HK for a year or more. I believe they are reliable however the usual caveats apply. If you pay by Paypal you will only risk $11, so if there is a problem, it's no big deal.

ken

Ken Fox wrote:Here's a deal I just found on the internet; a 1000g x0.1g scale for $11 delivered, from Hong Kong. Or, using coupon code "BULKRATE" you can get 3 of them for $30.71, which will include a mandatory charge for registered mail.

Amazing prices. How can they possibly make a profit? The shipping alone would kill ya.

"Our motto: we lose money on each unit, but make it up in volume."

Ken Fox wrote:Here's a deal I just found on the internet; a 1000g x0.1g scale for $11 delivered, from Hong Kong. Or, using coupon code "BULKRATE" you can get 3 of them for $30.71, which will include a mandatory charge for registered mail.

http://www.dealextreme.com/details.dx/sku.1165

I have bought one item from this website before, and have had no problems with them. The website is owned by a guy who split off from a partner who had another website that operated out of HK for a year or more. I believe they are reliable however the usual caveats apply. If you pay by Paypal you will only risk $11, so if there is a problem, it's no big deal.

ken

Wow, too bad I already bought and paid for a Triton T-2 on Ebay yesterday! Well, it's only a few bucks difference.

RapidCoffee wrote:Amazing prices. How can they possibly make a profit? The shipping alone would kill ya.

"Our motto: we lose money on each unit, but make it up in volume."

Who knows?

I think the shipping cost is very cheap; "registered mail" coming out of HK means something entirely different than it does here in the US, and I think it doesn't add much to the shipping cost. Since all of this sort of stuff is coming out of China these days, buying it in bulk close to the source is probably insanely cheap. If they can make a buck or two on each unit, they could be profitable, after all.

I have bought prescription eyeglasses and camera filters out of HK, and all of those packages were shipped "registered" mail. The postal clerks in my PO are astonished to find out that registered mail is being used for cheap things, whereas over here it is used for shipping items of value. Presumably a high risk of theft of regular mail is what motivates them to use that service.

ken