Vinegar wasn't much known in those days.
The process of making vinegar was still unreliable. They did user verjus though (juice of unripe grapes) which is very good in recipes, I make some every year during the season when my markets have mounds of them.
What people have presumed about Medieval food, for instance the heavy use of spices was to hide the taste of spoiled meat, is entirely false. Those who could afford spices and such were not eating spoiled meat. We have many documents with instructions to staff on how to select fresh meat in the early morning markets.
There wasn't much spoiled meat for the lower classes, because animals were slaughtered as needed, just before sale, and calibrated to be all sold during the day. The 14th century was a VERY structured time, and we have plenty of documentation.
Those who were not wealthy just couldn't afford meat, unless they raised pigs (which most people couldn't afford). Pigs were slaughtered in the Autumn because it was impossible to feed them through the winter. The meat was not spoiled. It was preserved by salting, drying and smoking. Also as confit, which is salted meat cooked very slowly submerged in fat, then sealed in a jar under the fat. It would last for months, or even a year or so. Sugar was not used for preserves because it was extremely expensive until the late 1700s.
Spices were used heavily, but they were used heavily because it was a show of wealth - they were extremely expensive.
When European ship technology became so advanced that worldwide voyages and huge capacity for spices and other luxury goods became available, the Arab and Venetian monopolies were broken and the price of spices plunged. With plunging prices came plunging use, because they were no longer a show of wealth. European cuisines quickly became as spice free as they were in the early 20th century.