(All answers are based on the psak of Rabbi Moshe Heinemann, shlita, Star-K Rabbinic Administrator.)

Q: What type of aged cheese requires one to wait six hours before eating meat?

A: Generally speaking, aging of cheese is an ongoing process, which occurs when the bacteria found in cheese breaks down the lactose (the milk sugar), creating lactic acid, thereby changing the physical property of the cheese, giving it a sharper flavor.

A good example of this aging process would be if someone were to leave a wedge of Muenster cheese in a nice warm environment until the cheese becomes “tangy.” The housewife would call it spoiled; a cheese maven would call it flavorful. Historically, flavorful cheese took about six months to age. The longer the cheese aged the harder it became. In Italy today, one can find some cheeses that have been aged for 24 months, which are impossible to break apart without a hammer. (It is important to note that if cheese is sitting in a refrigerator or cooler for long periods of time, it does not mean that the cheese is aging. An appropriate environment is required for the aging process to take effect.)

According to the Rema (Y.D. 89), one who has eaten hard cheese is required to wait six hours before eating meat, just as one who has eaten meat has to wait six hours before eating dairy. According to the TaZ (Y.D. 89:4), who comments on the Rema, the criteria for hard cheese is that it has been aged for six months, the time necessary to harden. However, in reality, cheese that has aged for six months does not automatically become hard. Stilton cheese, for example, is aged for six months but still has a creamy consistency. The Shulchan Aruch tells us that if the cheese is hard, one must wait six hours before eating meat. The Shulchan Aruch does not say that the cheese has to be aged for six months. If the cheese would harden in less time, then the six hour wait would be enforced. The TaZ above is giving a typical scenario rather than a time limit. Therefore, the Star-K’s policy for six hour cheese is cheese that has aged to the point that it can no longer be sliced, only grated.

Q: Hydroponic produce in supermarkets’ vegetable sections is rapidly expanding. What is the difference between vegetables grown in a greenhouse and those grown hydroponically?

A: Vegetables grown in a greenhouse are actually grown in soil in a controlled environment. Greenhouses offer the benefit of keeping out unwanted infestation. Hydroponically grown vegetables are grown in a solution of nutrients and water, rather than soil. The bracha one makes on greenhouse grown vegetables is Boreh Pri Hoadama, while the bracha on hydroponically grown vegetables is Shehakol Nihye B’dvaro, because the vegetables are not grown in soil.

Q: I understand that peeled raw onions should not be left overnight due to health precautions (sakana). Does this adherence apply to frozen onions that are commercially produced and sold in the frozen food section?

A: Based on a teshuva from R’ Moshe Feinstein (Y.D. 3:20), it is our custom to be lenient with processed commercial onions.

Q: On Shabbos does an observant Jew have to close a web site that is selling products on line?

A: Yes. As in the case of regular business transactions, no electronic business transactions may be made on Shabbos or Yom Tov on a web site belonging to a shomer shabbosbusinessman. The web site may remain open for information purposes, if the shopping cart on the web site is shut down. The time Shabbos and Yom Tov begins is determined by the entrepreneur’s geographic location.