Courier keeping holiday spirit, or our vintage three group San Marco Leva

Weather outside still cold. Mittens, hot drinks, windy bike rides tell us the holidays are still here. The streets were calmer this weekend, but places like Powell’s City of Books were bustling harder than ever. We spotted people traveling more often in groups than in ones and twos. This was most noticeable when looking into cars. People together equals holiday spirit to us.

At Courier we have many exciting side projects keeping us busy in the warmth of the roastery. One of them our La San Marco Spring/Lever two group from 1981. It is now propped on bricks sitting on recycled rubber pads. A stainless steel Synesso drain tray has been temporarily re-purposed to move water from drainbox to sink. We have been grinding and dosing with a Robur 110v grinder, wired with Delta fractional second timer. Last week we adjusted our incoming water line pressure to 25psi. This week we increased line pressure to 40psi, while adjusting the roller cam set screw down. At the peak of the eyelets contact with roller cam, water flow now approximates what we would see at the Half & Half Cafe, or the Little Red Bike Cafe. This is not set exactly and so tomorrow we will measure water volume vs. time.

There is an obvious source of channeling currently, in how we have our group set up. There is a notch at the bottom of every San Marco piston shaft, level at where the screen is held by the retaining clip. Water at pressure wants to go toward this gap, putting more force at the coffee grounds immediately below. Instead of water pressing equally through the puck of grounds locked into the portafilter, more water is pressed through the point of weakness. This part is getting over extracted, so that after all the goodness is pressed out, the awful bitterness is also pressed out. Technique may of course make up for this with the Leva, but why not make it better. Theoretically once the cavity of air above the coffee grounds fills, pressure equalizes between the line and the cavity. The cavity still has its own pressure barrier, the screen.

More positive forces at work this winter include a few new coffee friends serving Courier. Foster Burger opens soon, where Cava once was on 53rd and Foster.  Burgers, Milkshakes, rock and roll! Also Dovetail Baking opens for retail a few weeks into January, 30th and Alberta. Dovetail will be french pressing Courier Coffee all the time!

3 Responses to “Courier keeping holiday spirit, or our vintage three group San Marco Leva”

  1. FRENCH PRESSING ALL THE TIME!!!!!!!!!!!!!!!!!!! CAN’T WAIT!!!!!!!!!!!!!!!!!!!!!!!!

  2. justin says:

    just a thought, on my lever machine i use a LSM 21 gram basket, still with 16 odd grams in it. this seems to sort out the channeling problem quite well.

  3. joel says:

    we have not tried 21 gram baskets. I was thinking it had more to do with water bypassing the shower screen by way of the notch in the piston shaft. We have had other machines running recently and only a few days ago returned the LSM to operating condition.