Why organic milk often has a longer shelf life

Question: Why does organic milk have a longer shelf life than regular milk?

Answer: Most organic milk has an expiration date as much as a month past that found on cartons of regular milk. That’s because milk from cows fed organic, plant-based feed and raised without growth hormones or antibiotics is sold by fewer farms and therefore needs to travel farther to stores.

In order to make it to market while still fresh, organic milk is often ultrapasteurized, meaning it’s heated to 280 degrees or higher for at least two seconds. In regular pasteurization, milk is heated to 161 degrees for at least 15 seconds; it’s often fresh for about a week after purchase.

However, not all organic milk is ultrapasteurized. Organic dairies that supply their milk to local stores may use regular pasteurization. The label should indicate how it was processed.

Regardless of how milk is pasteurized, once a carton is open, the milk will remain fresh for less than a week.

Q: What is flint glass? I saw a collection at an antiques market, and it cost much more than other pressed glass for sale. Why?

A: In the world of collecting, the term “flint glass” covers American-made household objects created by pressing glass containing flint (a hard grayish quartz) into molds. Companies in the United States developed this method to imitate fine European crystal, blown and cut by skilled artisans.

From about 1820 to the 1860s, factories in New England, New Jersey and Pennsylvania turned out these housewares.

One way to distinguish flint glass from regular pressed glass is by striking it gently; its ring has a pure, long-lasting tone that resonates, like that of crystal. The material has more clarity and sparkle than other types of glass and casts a slightly gray shadow.

A shortage of artisans and demand for household wares after the War of 1812 led to the pressing of flint glass. Factories produced volumes of affordable glassware that mimicked crystal made by Waterford and other European companies, goods that were beyond the reach of even the well-to-do because of hefty tariffs.

To appeal to the desire for the new and different, firms such as McKee and Brothers, Boston and Sandwich, and New England Glass Company designed hundreds of patterns; names included Excelsior, Honeycomb, Ribbed Palm, Thumbprint, Sawtooth and Horn of Plenty.

Some flint glass came in vibrant shades, such as canary yellow, cobalt blue or emerald green. These brightly hued iterations were often well-used household favorites, so few have survived intact (thus, the higher prices).

Innovation ended the production of flint glass in the 1860s: Lime glass, developed in 1864, looked like flint glass, though it was a little less brilliant. Most important, it was cheaper to produce — just a third of the expense — since it weighed less and could be made more quickly.

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