I am a culinary instructor and professional cook in the Washington area, and I cannot remain silent after reading Robert Wolke's June 16 Food 101 column.
Any discussion about reducing a stock should begin with a review of the composition or technique of a stock. Unfortunately for the reader, Mr. Wolke's process for making a chicken stock is vague and condensed. I take particular issue with his reference to seasoning a stock, presumably with salt, before it is to be reduced. Any cook worth his or her salt knows that one never salts a stock that is to be reduced for the obvious reason that if a stock is perfectly seasoned at a weaker consistency, the salt becomes too strong as the stock is reduced.
The author suggested that less water could have been used to make a stock in the first place, squandering his opportunity to mention that there is an appropriate ratio of water to bones, vegetables and aromatics. If the reader takes Mr. Wolke's comment as a proposal to use less water to make a more concentrated stock cooked for the same time recommended by the author (three to four hours), the resulting stock will not have extracted everything the material has to offer. That is, there will not be enough water to thoroughly circulate with all the material. Additionally, the material in a stock should always be covered by liquid for reasons of sanitation as well as ease of skimming and removing fat.