Drying Green Tomatoes

Drying green tomatoes a is a quick way to deal with a glut of green tomatoes at a time of year when you may already be weary from a summer full of canning and already have more green tomato preserves on the shelf than you can ever use.

See also: Green tomato canning recipes

Yields and Equivalents

20 lbs fresh green tomatoes (9 kg) = 18 oz dried green tomato slices (510 g)

Directions

Here we compare directions from three different sources.

Note that two sources say peel first; a third source gives peeling as optional. When drying, this is not a safety question, but rather one of preference: when rehydrated, pieces of tomato peel may detach off and float around in whatever dish you are making.

(Note that green tomato peel can be dried on its own to be ground into green tomato powder, so there is no waste.)

Also note that none of the sources have you seeding the tomatoes.

Ball Blue Book

Preparation:  “Wash, dip in boiling water, 30 to 60 seconds, transfer to cold water. Core, and peel. Cut into slices ¼ inch (½ cm) thick.”

Blanching: None

Temperature: 145 F / 62 C

Time: Until crisp.

Notes: “Choose paste-type varieties.”

Water content: 94%. (Used if doing a Dehydration Weight Test.)

Reference: Ball Blue Book, 37th edition, 2014. Page 167.

Note: In the Ball All New, they suggest slicing or dicing. The suggested drying temperature is 125 F / 52 C.

Excalibur

Preparation:  “Wash tomatoes, dip in boiling water, then in cold water, then slip the skins off. Cut into ¼ inch (½ cm) slices; cut cherry tomatoes in half.”

Blanching: None.

Temperature: 155 F / 68 C

Time: “Until leathery or brittle.” Time estimate is 5 to 9 hours, depending on humidity in your area.

Notes: “High acid, full-flavoured tomatoes like San Marzano and Royal Chico are best for drying; low acid ones will turn black when dehydrated. Use only dark red tomatoes with meaty walls.”

“Low-acid tomatoes: puree them, adding 1 tablespoon lemon juice or vinegar to each quart / litre of pulp. Line trays with parchment, spread out on trays and dry as a leather. This can be powdered and used to make tomato paste or sauce.”

Quality: Good

Reference: Excalibur. Preserve it naturally. 4th edition, 2012. Page 26 and 59.

So Easy To Preserve

Preparation:

As slices: “Wash, trim our core and cut cross-wise into ¼ to ⅜ inch (½ to ¾ cm) slices. No peeling or blanching is necessary. Slices may be lightly sprinkled with crumbled dry oregano or other dry herb of your choice prior to drying.”

As chunks for stewing: “Steam or dip in boiling water to loosen skins. Chill in cold water, peel. Cut into sections ¾ inch (2 cm) wide, or slice. Cut small pear or plum tomatoes in half.”

Blanching: None for slices. For stewing chunks: steam blanch 3 minutes or water blanch 1 minute.

Temperature: 140 F / 60 C

Drying time: 6 to 12 hours for slices. 10 to 18 hours for stewing chunks.

Quality: Fair to good.

Reference: So Easy To Preserve. 6th Edition. 2014. Page 348 & 351.

Black colour

There are at least two possible causes of dried tomatoes turning black.

1. Excalibur says, “…low acid ones will turn black when dehydrated”;
2. So Easy to Preserve says, “Black color can develop because of oxidization.” (SETP, 2014, page 348) (air getting at them while in storage).

Oregon State Extension says,

To prevent tomatoes from darkening or turning black, heat the fresh slices before drying. The enzymatic reaction that causes the blackening will be reduced by steaming, blanching or heating in a microwave oven until the slices are heated throughout, but not cooked.” ^[1]Herring, Peg. Dry your home grown tomatoes. Oregon State University Extension. July 2006.

Storage

Let the dehydrated product cool completely to room temperature before packing it into storage containers.

Watch the sealed containers for the first few days for any sign of condensation. If condensation occurs, dehydrate a bit more.

Label jar with name of product and date. Store away from heat and direct light.

So Easy to Preserve says, “Dried tomatoes re-absorb moisture readily which causes undesirable color and flavor changes, and shortens shelf life. Package tightly.” (SETP, 2014, page 348)

The University of California Extension Service says, “The color, flavor, aroma and nutritive value of dried tomatoes will deteriorate after about a year. Well-wrapped tomatoes can be stored in the freezer for longer periods.” ^[2]Tracy L. Parnell et al. Tomatoes: Safe Methods to Store, Preserve, and Enjoy. University of California ANR. Pub. 8116. March 2004.

Usage notes

Use in soups and sauces, or combine with other vegetables for flavour. Can be powdered and used to make tomato sauces, paste or ketchup. Soak a bit in a salad dressing such as Italian dressing or simple vinaigrette then purée them into the dressing to make a tomato-flavoured dressing.

In Puglia, Italy, a pickled table condiment (“Pomodori verdi secchi in olio di oliva”) is made by rehydrating dried green tomatoes in vinegar, then soaking them in oil and serving as a condiment for sandwiches or the side of the plate.

The dried slices can also be ground into green tomato powder.

To rehydrate dried green tomatoes

The University of California Extension Service says,

You can rehydrate dried tomatoes in a variety of ways. You can add them directly to soups and stews or soak them in water, wine, bouillon, or vegetable juice. They usually rehydrate within 1 to 2 hours. If you soak them for more than 2 hours or overnight, you should refrigerate them. Use boiling liquid if you want to shorten the soaking time. The liquid used to rehydrate the tomatoes contains vitamins from the fruit and may be used in cooking.” ^[3]Tracy L. Parnell et al. Tomatoes: Safe Methods to Store, Preserve, and Enjoy. University of California ANR. Pub. 8116. March 2004.

The Master Food Preservers Group of Orange County, California, says:

Tomatoes rehydrate quickly so they can be used dry as they soften up with the moisture from other ingredients and leave a little pockets of “tomatoey” taste in your dish.  However, if you do need them soft you can rehydrate by soaking in either warm water or good quality oil (olive oil is most common) for about 10 minutes…. Rehydrate the tomatoes by marinating in a bit of salad dressing then enjoy tomatoes in your salad in the winter or on a sandwich.” ^[4]How to Use Dehydrated Tomatoes. UUCCE Master Food Preservers of Orange County. Accessed Dec. 2017 at https://ucanr.edu/sites/MFPOC/Food_Preservation/Tomatoes/How_to_Use_Dehydrated_Tomatoes/

Cooks Illustrated says,

Place ½ cup [dried] tomatoes in heatproof bowl, cover with 1 cup broth (250 ml / 8 oz) or ½ teaspoon salt dissolved in 1 cup (250 ml / 8 oz) warm water, then cover with plate and microwave for 2 minutes. Let sit until skin side of tomato can be pierced easily with fork, 5 to 10 minutes. Drain and blot well with paper towels.” ^[5]Cooks Illustrated. The Best Way to Rehydrate Sun-Dried Tomatoes. January 2016. Accessed January 2018 at https://www.cooksillustrated.com/how_tos/9820-the-best-way-to-rehydrate-sun-dried-tomatoes

Further reading

How to Use Dehydrated Tomatoes. UUCCE Master Food Preservers of Orange County. (Link valid as of Dec. 2017)