Executive Summary: I believe I'm on the right path. I have stopped lowering the heat so drastically due to my model of smooth top electric stove. I have also let the coffee bubble up top for 90-120 seconds and have been getting complete draw downs with a total coffee/water contact time of 4-7 minutes up top. The resulting cup has improved drastically.All your technique sounds spot-on. When guys ask me for suggestions on stalls, I first encourage them to narrow the problem. Start with the grinder. I am suspicious of the Maestro and the possibility of throwing 'fines.' Eliminate the grind as the issue.
B|Java
Thanks for the reply Dave! I was also suspicious of the Maestro. It's certainly a mid grade conical burr grinder. Not suitable for espresso grinding but more targeted to french press/drip.
I used my Macap M4 for 3 or so batches; experimenting with a few different partical sizes from espresso to right below drip to see if it made a difference. I experienced the same issues of stalling out even with use of a good grinder.
Last night my luck turned for the better resulting in two perfect draw downs. The first was with the cloth filter in the 4 cup Cory with 32 grams of coffee. The second was with the glass rod in the Yama with 5 cups of water and 40 grams of coffee. The coffee was ground at the same partical size in the Meastro. This particular coffee was decaf roasted to Full City ++ several weeks ago. It was a long shot with this oily bean and a risk I thought would probably pose more problems with the vac pot brewing method. Still, the draw downs were complete and ideal.
I modified my procedure to let the coffee steep for 90-120 seconds and added it when 80% of the water had travelled to the upper globe. This resulted in vigurous draw downs with copious bubling and downward "woosh." The coffee lacked any hint of bitterness and was sugary sweet with great body and very little sediment. I was ecstatic! Truth be told, I preferred the cloth filtered coffee at a lower coffee/water ratio.
This morning, with the Yama filled to 8 cups of water with 64 grams of coffee I experienced a total draw down without lowering the heat significantly. I had started with the heat at 6.5/10 and lowered to 5/10 when 80% of the water was up north. Same grind level using the Maestro, different coffee, but one that was roasted to Full City++ and also with quite a bit of visible oil.
I'm guessing reducing the heat too drastically was compromising vacuum strength. Perhpas it was not strong enough to pull the liquid down through the coffee? I also think not letting the coffee brew long enough with heat applied. Maybe this was resulting in a excess build up of oils and grounds around the base of the filter rod prior to draw down/
This all is making sense. My stove is a newer electric smooth top model that cycles the heating element off when the set temperature is achieved. Perhaps lowering the heat to 2/10 was the culprit of my woes? The element would cycle off completely for an extended period of time when set to 2 or 3/10.
There have been immediate improvements NOT lowering the heat significantly and letting the grounds steep for a longer period of time in the upper globe. This has resulted in a total water/coffee contact time of 4.5-7 minutes. I can't see any dancing of the rod or hear clinking even at 5/10 on the stove.
I'm going to keep experimenting with this. IMHO I'm currently drinking some of the finest coffee I've brewed at home in quite a while. The resulting coffee is sugary, rich and complex with great body. No increase in sediment is visible at the bottom of the pot. Good stuff!
Thanks for the wealth of info in this thread! I feel practice and refining the procedure has me on the right track! The information in this thread has been a great baseline. Varying the procedure based upon my equipment has gotten me closer to coffee bliss!
I'm looking forward to brewing my recently roasted batches which have been specifically targeted towards use in the vac pots!
