To give you an idea, to dehydrate and concentrate enough estrattu to fill one jar takes about 10 pounds of the sauce! And the flavor is very intense. Think of it as tomato paste with an attitude.
The handmade paste is a backbreaking, hot summer job. First, you must start with fresh plum tomatoes with skins and seeds removed. The tomatoes are cooked into sauce with the addition of onions, local herbs like oregano and basil and salt and spices. There is no standard recipe since the method varies from place to place and every cook will tell you that his or her method is the tried and true one.
The sauce is spread on long boards or placed in shallow tin pans, topped with screens to keep bugs away and placed in the searing Sicilian sun where it is frequently moved back and forth by hand with small implements resembling paddles to help it dry and remove the excess liquid. This process takes days. The whole idea is to wind up with a very paste-like consistency that is called estrattu, strattu or strattu ri pumaroru, i.e. tomato paste.
Radical differences in climate between Sicily and New England, where I live, make it impossible to recreate estrattu here. But there is a way to make something similar by using a dehydrator. I have done this many times, and although it is not exactly the same taste as estrattu, it makes a really good substitute. To do it, use ripe plum tomatoes that have been washed, dried and cored. Cut them in half lengthwise and place them cut side down on the dehydrator and dry them according to the manufacturer’s instructions.
Remove them when they are the consistency of dried apricots. This could take a day or two depending on the dehydrator and the size of your tomatoes. No dehydrator? Place the cut tomatoes on racks placed over baking sheets and place them in a 250F oven. This could take even longer.
Place the dried tomatoes in a food processor and puree them into a paste. Through the feed tube add just enough extra virgin olive oil to smooth out the tomatoes but don’t add too much. The mixture should remain thick like the consistency of peanut butter.
Transfer the paste to a bowl and add salt and a grinding of black pepper to taste. Fill jars with the paste, cap and refrigerate or freeze. Then add it to your recipes in small amounts to really beef up the cooking flavors. A little goes a long way in soups, stews, pasta and in sauces.