Into the woods by 5:15 AM to cook. Temperature 40 with rain. Rain was forecast to change to sleet or snow later in the day as the temperature droped. The ground is still frozen so the rain accumulates into large puddles. We saw similar conditions in the 2022 season with deep frost and rain. After the frost came out, we got large sap runs.

Got the R/O going by 6:00 AM. However, when increasing the pressure setting on the high pressure pump that does the concentrating, the top lid on the pressure vessel that contains the membrane, leaked. The lid is 4” in diameter. It bolts to the pressure vessel. It has a plastic insert with an O-ring to seal where the lid meets the vessel. We considered replacing this O-ring during setup because it’s over 5 years old. We should have replaced it. We’ll replace before the next use.

Stopped the R/O. Unbolted the lid. Added more food grade grease around the O-ring to help seal. We still had a small leak, but pushed on with concentrating. While reassembling, we dropped a nut and couldn’t find it. We scrounged around the garage to find a replacement. This set us back 45 minutes. It was 6:45 AM before we resumed R/O operations. We’ll pick up spare nuts and bolts for the lid. After we finished cooking, we found the nut 2’ behind us. That wasn’t expected. We search around the R/O, but not behind where we stood.

It took over an hour to refresh and relearn the R/O adjustments. At one point we were at 9 Brix. The R/O is rated for 8 Brix and can’t sustain a higher level. We also had to lower the pressure because of the suspect O-ring. We settled in at 6 Brix.

The R/O finished by 10:35 AM. We were cooking at almost the same rate the R/O was concentrating sap. 1 ½” remained in the concentrate tank when the R/O finished. In Past seasons, the tank had 4” – 8” because we were concentrating faster than cooking. It’s nice to concentrate and cook at the same rate, but this could indicate the R/O wasn’t preforming as well as it’s rated. We typically get 90-95 gallons/hour with the R/O. Today it was 65 gallons per hour. The hope is the O-ring replacement will allow higher pressure to give better performance.

We finished cooking shortly after 11:00 AM, then configured the R/O for a wash cycle. We were back to the farmhouse by 11:30 AM just as the rain changed to sleet/snow.

The day cooking
6:00 AM R/O starting
7:00 AM 2” concentrate tank
8:00 AM 1 ¾”
8:30 AM batch
9:00 AM 2”
9:30 AM batch
10:00 AM 1 ¾”
10:10 AM batch
10:35 AM R/O done
10:55 AM batch
11:10 AM done