Tomatoes

Oven-drying tomatoes

Susan M. Selasky * Detroit Free Press Test Kitchen * July 28, 2010 via the Lansing State Journal and the Info-Ideas-Tips-N-Tricks mailing list on cooking-lists.com

Prepare: Roma tomatoes are best for oven-drying. Remove their stems, rinse them under water and pat dry. Cut the tomatoes in half lengthwise.
Core and remove the seeds. Line a baking sheet with parchment paper.
Place the tomato halves, skin side down, on the parchment.

Bake: Preheat the oven to 200 degrees. Bake for 8 to 10 hours for tomatoes that are about 3 1/2 inches long. Smaller tomatoes will take less time. Start checking them after about 6 hours. The tomatoes should be drying out and shriveling. When done, they will be reddish-brown flat pieces about 1 1/2 inches long.

Store: Keep them in the refrigerator for about a month or in the freezer for six months for best quality.

Use: Rehydrate them in hot water. Use kitchen scissors to cut them and use on pizzas and in sauces, soups and pasta dishes.

Canning

Quality: Select only disease-free, preferably vine-ripened, firm fruit for canning.

Caution: Do not can tomatoes from dead or frost-killed vines. Green tomatoes are more acidic than ripened fruit and can be canned safely with any of the following recommendations.

Acidification: To ensure safe acidity in whole, crushed, or juiced tomatoes, add two tablespoons of bottled lemon juice or 1/2 teaspoon of citric acid per quart of tomatoes. For pints, use one tablespoon bottled lemon juice or 1/4 teaspoon citric acid. Acid can be added directly to the jars before filling with product. Add sugar to offset acid taste, if desired. Four tablespoons of a 5 percent acidity vinegar per quart may be used instead of lemon juice or citric acid. However, vinegar may cause undesirable flavor changes.

Recommendation: Use of a pressure canner will result in higher quality and more nutritious canned tomato products. If your pressure canner cannot be operated above 15 PSI, select a process time at a lower pressure.

If a procedure from the USDA Complete Guide to Home Canning for canning tomatoes offers both boiling water and pressure canning options, all steps in the preparation ("Procedure") are still required even if the pressure processing option is chosen. This includes acidification. The boiling water and pressure alternatives are equal processes with different time/temperature combinations calculated for these products.

Whole or Halved Tomatoes (packed in water)

Quantity: An average of 21 pounds is needed per canner load of 7 quarts; an average of 13 pounds is needed per canner load of 9 pints. A bushel weighs 53 pounds and yields 15 to 21 quarts-an average of 3 pounds per quart.

Please read Using Pressure Canners and Using Boiling Water Canners before beginning. If this is your first time canning, it is recommended that you read Principles of Home Canning.

Procedure for hot or raw tomatoes filled with water in jars: Wash tomatoes. Dip in boiling water for 30 to 60 seconds or until skins split; then dip in cold water. Slip off skins and remove cores. Leave whole or halve. Add bottled lemon juice or citric acid to jars (See acidification directions). Add 1 teaspoon of salt per quart to the jars, if desired.

Raw pack -- Heat water, for packing tomatoes, to boiling. Fill hot jars with prepared raw tomatoes, leaving ½-inch headspace. Cover tomatoes in the jars with boiling water, leaving ½-inch headspace.

Hot pack -- Put prepared tomatoes in a large saucepan and add enough water to completely cover them. Boil tomatoes gently for 5 minutes. Fill hot jars with hot tomatoes leaving ½-inch headspace. Add cooking liquid to the jars to cover the tomatoes, leaving ½-inch headspace.

Adjust lids and process according to the recommendations in Table 1, Table 2, or Table 3, depending on the method of canning used. (Acidification is still required for the pressure canning options; follow all steps in the Procedures above for any of the processing options.)

Table 1. Recommended process time for water-packed Whole or Halved Tomatoes in a boiling-water canner.
		Process Time at Altitudes of
Style of Pack	Jar Size	0 - 1,000 ft	1,001 - 3,000 ft	3,001 - 6,000 ft	Above 6,000 ft
Hot & Raw	Pints	40 min	45	50	55
	Quarts	45	50	55	60

<tbody>

Table 2. Recommended process time for water-packed Whole or Halved Tomatoes in a dial-gauge pressure canner
			Canner Gauge Pressure (PSI) at Altitudes of
Style of Pack	Jar Size	Process Time	0 - 2,000 ft	2,001 - 4,000 ft	4,001 - 6,000 ft	6,001 - 8,000 ft
Hot & Raw	Pints or Quarts	15 min	6 lb	7 lb	8 lb	9 lb
		10	11	12	13	14

<tbody>

Table 3. Recommended process time for water-packed Whole or Halved Tomatoes in a weighted-gauge pressure canner.
			Canner Gauge Pressure (PSI) at Altitudes
Style of Pack	Jar Size	Process Time	0 - 1,000 ft	Above 1,000 ft
Hot & Raw	Pints or Quarts	15 min	5 lb	10 lb
		10	10	15
		1	15	Not Recommended

This document was adapted from the "Complete Guide to Home Canning," Agriculture Information Bulletin No. 539, USDA, revised 2009.

External links

• http://www.uga.edu/nchfp/how/can3_tomato.html