Air carrier Captain reported continuous turbulence during cruise that caused altitude deviations. The flight crew notified the company of the weather conditions and submitted a Maintenance logbook write up.

Narrative

While dealing with continuous moderate turbulence for over an hour; including an event of unable to maintain altitude due to high level wind shear that caused us to descend from 370 to 350 previously; we encountered what I would describe as severe chop. The aircraft was not significantly displaced; there was never any doubt as to maintaining control; and no limits were exceeded in airspeed and no high G situations were encountered. I could best describe it as experiencing a corduroy road at high speed such that the aircraft did shake hard enough that the instruments were hard to see at times; items were tossed off the galley counter and the company app recorded the event as Moderate occasionally severe turbulence. No passengers were up; the seatbelt sign was on the entire time; the flight attendants had been seated for close to an hour by my estimation and they had been advised of the chop/turn and were in contact with us throughout periodically with good CRM. There was no [priority handling requested]. We communicated the report and our situation with Dispatch via ACARS. I further communicated with Maintenance Control prior to making the ELB (Electronic Log Book) report. The ELB report included the details that no airspeed limits were exceeded and no high G situations were experienced.