Having been forced to change the grind of several different grinders as their hoppers emptied, I'm firmly in the camp of either single dosing or using a short weighted column hopper that's replenished after every grind.mitch236 wrote:Ian, that was exactly what I was looking for! I'm in the column camp but might have to find a lighter weight!
But like Jim, I'm a bit skeptical about the short weighted column versus single-dosing with a weight or lid. The argument for the column appears to be that you get consistent pressure on the beans going through the burrs, while with single-dosing you lose all pressure as soon as the weight or lid hits the hopper supports, center screw of the moving burr, etc. But in the case of the column, the weight pressing down on the beans does, in fact vary as you grind the shot: it decreases by the weight of the beans just ground. Now, whether this variation is superior to the variation caused when the weight or lid loses contact with the beans in the single-dosing case is a matter of pure speculation.
My guess: it doesn't matter as long as you adjust the grind accordingly (Jim's assertion about hopper versus single dosing.)
And this leads me to assert that single-dosing is superior because it allows you to switch coffees at any time without waste and you don't have any problems when you have less than a full column of beans left in the bag.
The more important takeaway I get from this thread and the thread on popcorning is that certain coffees may benefit from as light a weight on the bean column as possible. As has been stated, the lighter weight will require a finer grind, which may benefit lightly roasted SOs, similar to the effect postulated by Jim for the finer grind required for VST baskets.
Following Jim's example, I put a single dose in the throat of my K10 and put a Spice Islands jar on top to keep beans from flying out. The jar is filled with peppercorns and I have never opened it (the lid seal is still intact.) I just weighed the jar and it came in at just over 190g. Much heavier than I expected. The label says the net weight of the contents is 2.4 OZ, so getting rid of the peppercorns will reduce the weight by about 67g. Removing the lid will save a few grams, too. I might be able to get the weight down to 100g. Perhaps I can cut the jar in half or less and get it down even lower. Here comes another espresso science project...