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Is there a product that extracts air from plastic freezer bags and seals them for storage?
I would caution you about sealing foods at home in an airless environment. This is the perfect environment for the growth of Clostridium botulinuum, the microorganism which causes botulism food poisoning which can be fatal. This bacteria likes an airless (anaerobic) environment and low acid conditions.
GH1505, Quality for Keeps: Freezing Home-Prepared Foods without vacuum packaging is a safe way to preserve extra food.
Barbara Willenberg
Associate State Nutrition Specialist
Are some cheeses lactose free?
Cheeses that have been ripened, such as cheddar and Swiss, have virtually no lactose remaining in them. The process of producing these cheeses removes about 90 percent of the lactose in the whey. During the curing process, the starter bacteria ferments the remainder of the lactose within several days of manufacture. Mozzarella, cottage, cream and other non-ripened cheeses contain differing concentrations of residual lactose. However, the amount one would consume in a normal serving is highly unlikely to have an effect on a person who needs to limit lactose in the diet.
Robert Marshall
Professor Emeritus of Food Science
Why is a country ham a shelf stable product?
The intact country ham is considered a shelf stable product for several reasons.
The traditional manner of production involves the application of a suitable cure followed by an extensive period of drying and aging at ambient conditions. Since production includes steps where the temperature is often approaching or exceeding 100 degrees Fahrenheit, it is obvious that the product can withstand storage at typical room temperature without additional protection.
The nature of the elevated salt concentration and dehydration during manufacture are the principal reasons for the product being preserved and shelf stable.
Shelf stability really just means that the product undergoes little change or slow change during the observation period at normal ambient temperature.
While a country ham takes months to prepare, it also takes months at room temperature to show signs of change. Some change still takes place, like additional dehydration and possible mold growth, but these are not dramatic effects.
A concern of some people is safety of the product when it is kept at room temperature, but this is situation where one may have missed the point -- especially when room temperature is quite cool when compared to the production and aging temperature.
Furthermore, there is no evidence that bacterial growth should be a problem in products with low water activity like country ham. One must remember that a country ham is considered a raw product and thus is not a ready-to-eat item.
Andrew Clarke
Associate Professor of Food Science
My favorite brand of hand cut cottage cheese is no longer available. I have not been able to eat any of the other commercial brands. Is it possible to come up with a homemade version that is comparable?
It is a virtual impossibility to duplicate some commercial products in a home operation.
The major problem will be getting the rennet or chymosin and the lactic starter culture.The process calls for inoculating warm skim milk with an active starter culture, the amount varying with the planned time of production. Any dairy's skim milk will work.
There is both a long-set and short-set method. I suggest short-set. In that method skim milk at 90 degrees Fahrenheit is inoculated with 5 percent lactic starter culture and stirred well for 10 minutes.
After about 30 minutes rennet should be added. The only source is probably Junket Tablets that some stores still sell. The recipe in the packet should be followed.
The milk will coagulate and form a gel that gets more firm as acid is produced by the bacteria.
The curd is ready to cut when it breaks cleanly as evidenced by insertion of a glass thermometer or similar instrument (or finger) at a 45 degree angle and lifting upward. The curd should be cut into cubes measuring 0.3 to 0.5 inch on each side. (This is not possible in the home without special instruments. So. cutting with a long knife at a 45 degree angle in three directions can be done.)
After cutting, the curd is left undisturbed for 15 minutes while heat is applied slowly. A double boiler is needed for this operation. Temperature in the vessel should be raised 1 degree Fahrenheit each 5 minutes for 30 minutes and, thereafter, at 2 degrees each 5 minutes until the temperature reaches 135 degrees Fahrenheit -- about 2 hours total.
Stirring should be done gently in the beginning while the curd is quite fragile, but frequent stirring is needed to prevent matting of the particles. The force applied should be increased as the curd firms. When particles of curd are firm after dropping into cold water, the whey is to be drained to the point at which it first disappears below the surface of the curd mass.
Wash this curd in water at 60 degrees Fahrenheit for 20 minutes. Drain this water and add a second volume of water at 40 degrees Fahrenheit stirring for another 20 minutes. Drain completely.
To the dried curd add one third the weight of half and half plus 0.7 to 1 percent salt on the basis of total weight of the creamed curd. Since there is no stabilizer in this mix, the cream will run more freely from the curd than it does with most commercial creamed cottage cheeses. Therefore, less cream dressing may be desired.
You can see that this is a long and involved process. I recommend finding another source of desirable cottage cheese. However, it can be fun experimenting.
Cottage cheese can be made without rennet, i.e., acid alone will produce curd. The curd is far more fragile than renneted curd since acids remove much of the calcium that binds together the casein (protein). In any case pasteurized skim milk will not sour naturally and any attempt to cause it to do so sans a good lactic culture is doomed to failure.
Robert Marshall
Professor Emeritus of Food Science
Can I store whole turnips in the basement where it is dark? How long will they keep?
Storage recommendations for turnips are the same as for carrots. Wash roots, trim tops to 1/2 inch, place in perforated plastic bags and store in refrigerator, cold moist cellar or pit. Storage life is two to four months. G6226, Vegetable Harvest and Storage gives information on how and when to harvest vegetables, special harvest preparations and storage requirements, and appropriate length and kinds of storage.
Candance Gabel
Associate State Nutrition Specialist
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Updated 5/16/06