I'm wondering if anyone has come up with a method for at determining at least a ballpark grind setting for a new bean before committing and potentially pulling a sink shot. I've got some particularly expensive coffee I'm working with and I'm trying to waste as little as possible.

On my Compak K10 fresh, I use the digital display to note grind setting for various beans, and even with aging, humidity changes, frozen coffee, etc, I can successfully come back to a shot that's drinkable, and sometimes spot-on.

What I've attempted to do with new coffees is compare the whole beans against known coffees, and see if I can come to a starting point at least. My approach is to weigh a vessel filled with one coffee, then the next, and compare the results. This appears to work reasonably well on beans of similar sizes, but in the case of a peaberry I'm working with, I don't think this method holds up.

Is there a better way? Is this approach futile? Knowing these forums, this has probably been discussed already and I just missed it with the search terms I used, so I apologize if I'm rehashing something.

thanks,

frank

While reading your post I was about to suggest what you actually do, as noted in the second part of your post. Comparing to known or cheaper beans.

My initial impression of "ballpark" was within say 10 seconds of desired flow. That would be enough for me that I wouldn't sink the shot. Am I off with the 10 second estimate? or are you looking for something better than that?

My basic approach, with all my grinders, is to identify a setting that works well as an "average," meaning that it pulls at an appropriate rate for roasted beans that are moderately roasted, with around 6-8 days of rest, at my most common dose. I mark that setting and use it as a reference point when I am starting with a new coffee, and then adjust finer or coarser if the beans are roasted lighter or darker than usual, or if I am trying a non-standard dose right out of the gate. With practice, this all gets fairly intuitive, including the size of the initial adjustments, and you will find that you rarely sink your first shot, even if you think it could be improved with further grind adjustments.

I should also mention that this assumes single-dosing by weight. Given the variable dose weights that occur when dosing by time or volume, I would expect the first shot of a new coffee to vary more using those methods.

Thanks for the replies. I'd say within 10 seconds is acceptable on one side of the shot at least -- that is 10 seconds too long, but if I'm shooting for a 25 second pull, I'd probably throw away a 15 second pull. I guess it makes sense then that I usually err on the side of too fine when working with a new coffee.

My approach thus far has been to try and take altitude (bean density) and roast degree into account when guessing where to start with a new coffee, but I've found even my best guess will be pretty far off sometimes, especially when switching between growing regions.

The outliers for me seem to be Guatemala's -- I've roasted a couple lately that were way off with my default grind, probably in the neighborhood of 2 grams difference, if I were to compensate that way. These were properly developed coffees, just exceptionally hard beans I guess.

I am single-dosing by weight, at least for my initial shot. On the K10 fresh if I start with an empty hopper I now know I need to add an additional 1.5 grams of coffee to approximate where the next shot will be, taking the effect of popcorning, or whatever you want to call the effect that makes the first shot so much coarser than the subsequent ones.

I guess this is an intellectual exercise more than anything, since I can usually afford to spare the extra 50g is takes to get a coffee dialed in, it would just be nice to waste that much less coffee

This is where grinding & pulling notes really help I find. When trying out new beans I take notes of my dose weight, grind setting and result in the cup. Notes as to the type of bean, origin, roast level etc are noted. When I get a completely new bean I note the origin, roast level, bean size, and then look for something similar in the notes - start with that bean's grind setting.

This may sound tedious, but I only run 5-10 origins through my house annually, so it's really not that big of a chore.

Just this last weekend I was demoing my NS Oscar & B. Vario for a buyer with a bean that hasn't gone through those machines. Buyer wanted a shot demo, so I pulled out my Vario grinder notes and picked a bean similar - it was too coarse so I picked the next most similar bean and it's grind setting. Right on the money. Beautiful extraction that the guy, a newly trained barista, was overjoyed to sample.

Now I have to build up the same data info for my new K10.