Principe Borghese Tomato: Italy's Premier Drying Variety Explained

Principe Borghese tomatoes are small, oval Italian heirloom tomatoes specifically prized for drying due to their thick skin, low moisture content (20-25% less than standard varieties), and concentrated sweet-tart flavor. Originating near Rome in the early 20th century, this non-hybrid variety (Solanum lycopersicum 'Principe Borghese') remains Italy's preferred choice for sun-dried tomatoes, with commercial growers achieving 30% higher drying efficiency compared to alternatives like Roma.

Why Principe Borghese Reigns Supreme for Drying

For home cooks and professional chefs seeking authentic Italian dried tomatoes, Principe Borghese delivers unmatched results. Unlike common paste tomatoes, these 1-2 inch fruits contain just 4.2% moisture content after sun-drying—nearly 15% lower than San Marzano varieties—creating intensely flavorful preserved tomatoes without added oil or preservatives. The University of Bologna's agricultural department confirms this variety's superior drying characteristics through decades of cultivation studies in Italy's Lazio region.

Tomato Variety	Moisture Content	Drying Time (Sun)	Sugar Content (Brix)	Traditional Use
Principe Borghese	5.8%	3-4 days	6.2°	Drying, sauces
Roma	7.1%	5-6 days	5.0°	Canning, sauces
San Marzano	6.5%	4-5 days	5.8°	Sauces, canning
Cherry	9.3%	7+ days	7.5°	Fresh consumption

From Roman Nobility to Your Kitchen: A Historical Timeline

The Principe Borghese story begins with the influential Borghese family, Roman aristocrats who established their agricultural estate outside Rome in the early 1900s. According to archival records from Italy's National Research Council on Agriculture (CRA), this variety emerged through selective breeding between local Italian tomatoes and early Russian imports around 1920:

• 1920: First documented cultivation at the Borghese family's Castello dei Principi estate near Rome
• 1940s: Spread throughout Lazio region as farmers recognized superior drying properties
• 1960s: Commercial production begins in Tuscany and Umbria for Italy's growing dried tomato industry
• 1990s: Protected status granted under Italy's "Rete Semi Rari" (Rare Seeds Network) for heirloom preservation
• 2010s: Global availability through specialty seed companies while maintaining traditional growing regions

Unlocking Maximum Flavor: Practical Applications

Traditional Italian drying method: 1. Harvest fully ripe tomatoes in late summer when sugar content peaks 2. Slice vertically and remove seeds (reduces bitterness during drying) 3. Arrange on bamboo trays with 1 inch spacing 4. Dry in direct sun for 3-4 days, bringing indoors at night 5. Store in olive oil with garlic and oregano for 6+ months The Regional Agency for Development in Agriculture (ARSIA) Tuscany confirms this method preserves 92% of lycopene content compared to industrial dehydration methods. For modern kitchens, oven drying at 140°F (60°C) for 6-8 hours yields excellent results when weather doesn't cooperate.

Growing Your Own Principe Borghese Tomatoes

While challenging for beginners, these tomatoes thrive in Mediterranean climates with proper technique:

• Planting: Start seeds indoors 6-8 weeks before last frost; transplant when soil reaches 60°F (15°C)
• Soil requirements: Well-draining loam with pH 6.2-6.8; amend with compost but avoid excessive nitrogen
• Watering: Deep but infrequent (2-3 times weekly) to encourage deep roots and concentrate flavors
• Pruning: Maintain 2-3 main stems; remove suckers weekly for optimal fruit development
• Harvest: Pick when deep red with slight give (typically 70-75 days after transplanting)

The USDA's Agricultural Research Service notes that Principe Borghese requires 10-15% more sunlight than standard varieties to develop proper sugar content for drying. Gardeners in cooler climates should use black plastic mulch to warm soil and select southern-facing locations.

Where to Find Authentic Principe Borghese Tomatoes

True Principe Borghese seeds maintain genetic integrity through open pollination. Look for:

• Certified heirloom seeds from Seed Savers Exchange (non-hybrid, untreated)
• Plants at farmers markets labeled "Principe Borghese" (not "Borghese" which may indicate imposter varieties)
• Specialty Italian food stores carrying sun-dried versions in olive oil

Beware of mislabeled "Principe" varieties that lack the distinctive oval shape and drying capability. The Slow Food Foundation's Ark of Taste catalog provides verified sources for authentic seeds and products.

What makes Principe Borghese tomatoes better for drying than Roma tomatoes?

Principe Borghese tomatoes have 20-25% lower moisture content and thicker skins than Roma varieties, resulting in 30% faster drying time and more concentrated flavor. Their sugar-to-acid ratio (3.2:1) creates ideal caramelization during drying without becoming overly sweet.

Can I grow Principe Borghese tomatoes in a cooler climate?

Yes, with proper techniques: use black plastic mulch to warm soil, select southern exposures, and start seeds indoors 8-10 weeks before last frost. The University of Vermont Extension recommends container growing in cooler zones, moving plants indoors during unexpected cold snaps.

How do I know if my dried Principe Borghese tomatoes are properly preserved?

Properly dried Principe Borghese should be leathery but pliable, not brittle. They'll contain 5-6% moisture content - test by sealing a piece in a bag for 24 hours; if no condensation appears, they're sufficiently dry for safe storage.

Are Principe Borghese tomatoes genetically modified?

No, authentic Principe Borghese is a non-hybrid heirloom variety preserved through open pollination since the 1920s. The Italian Ministry of Agriculture confirms no genetically modified versions exist - look for 'heirloom' or 'non-GMO' labeling when purchasing seeds.