Like any other practical skill, canning and preserving take practice to build expertise. From my first canning session at the end of spring, I learned that you can’t shortcut recipes unless you know what you are doing and that you MUST make sure to cook down your jam until it reaches the gel stage. If it’s syrupy instead of gel consistency when it goes in the jar, it will be syrupy still when it comes out. To make myself feel better, I like to tell people I didn’t fail in making strawberry jam, I succeeded in making strawberry compote. Still, the lesson was obvious: cook the jams down properly.
During my second canning session, or the weekend of 10 thousand peaches as I like to call it, I learned that pressure canning jams for too long (anything greater than 5 minutes) or under too much pressure (anything more than 6 pounds) threatens to break down the natural pectin gel you created with the concentrated cooking. I didn’t figure this out until I was almost finished canning (I had been processing my jams for 10 minutes at 10 pounds). Luckily, my jams from this session are still acceptable in their jam texture, but they’re a little more runny than I prefer.
During the canning session I organized yesterday, I was pretty excited about the jam making. I was sure I’d finally mastered the technique and had a willing audience of trainees ready to participate and learn. Sure enough, we created a mixed berry jam (blackberry, blueberry, raspberry) and it came out perfect. Perfect! We moved onto a rose petal jam and because I was also busy overseeing pasta sauce production, I wasn’t as attentive as I should have been and the jam cooked for a few minutes more after reaching the jam stage. Guess what? Turns out that not only can you undercook jam (too runny) you can overcook it, rendering it into some kind of super sweet caramelized candy that might pull your fillings out. Oopsie. Looking on the bright side, I didn’t fail at making rose petal jam, but succeeded at making rose petal candy. There were only 2 of us who had signed up for an order of this kind of jam (out of the 8 attendees) so at least the damage was contained. I think it will be repairable if when opening the jars of this “jam” we drop in a T of water and then zapp it in the microwave for 30 seconds to liquefy it again. Hopefully then when it cools down it will be the right texture.
When I do things, I like to jump in head first, with no hesitancy and go BIG. So when we decided to can my favorite pasta sauce recipe I led the charge in purchasing one hundred pounds of fresh Roma tomatoes for the project. Now I have made this sauce in small batches a few times and it’s a fairly standard process: rinse about 3 pounds of tomatoes, put them whole into a saucepot with 1/4 cup of water, let them cook down until they burst and you can easily crush them with a masher, run them through a food mill using the medium sized disc, return the expressed juice and pulp to the stovepot, add 1/4 cup olive oil and 3 cloves garlic, cook down till reduced by half, salt to taste, and add basil. Normally the reduction process takes about 45 minutes but I vastly underestimated how much longer it would take when working with larger quantities of tomatoes. And of course when canning the finished sauce you have to add on the time required to complete the canning process (10 minutes+ to get the water boiling, 10 minutes to express air once water vapor begins to rise from the closed and locked canner, then about 10 minutes+ waiting for the pressure to rise to 11 pounds, then 25 minutes processing at that pressure to kill off all the botulism spores*, then approximately 20 minutes for the canner to depressurize naturally before you can safely open it to remove the finished product). Our team of eight worked all afternoon yesterday on the task and even with duplicate work tools (two food mills, multiple pots for cooking down the sauce, two pressure canners, etc), after 6 and a half hours we only had processed 75 pounds of the tomatoes into canned sauce. And I was so busy directing the process and teaching I didn’t take the time to make notes during the process on lessons learned or yield measurements. Today I finished up the last 25 pounds of tomatoes and with a less frenzied and more relaxed atmosphere I had the time to take notes. Here is what I learned:
1. Every 25 pounds of raw and plump Roma tomatoes will fill three up 12 quart stockpots.
2. Cutting the raw tomatoes in half before putting them in the pots will allow them to soften faster.
3. After you cook down and run these 25 pounds of softened and mashed tomatoes through a food mill you will end up with one large stockpot (16 quarts) of juice and pulp.
4. After you reduce the juice and pulp to sauce consistency (aim for approximately half the quantity you began with) and adding in your other ingredients, you will have a yield of 8-9 quarts of rich, fresh, all natural tomato sauce.
5. Timing: Every 25 pounds of raw tomatoes takes approx one hour to rinse, cook down, mill, and get back in the pot to begin the reduction. The reduction process for this quantity of tomatoes takes approx 4 hours. The canning process takes approx 1 hr and 20 minutes.
6. Tomato season and pricing: Roma tomatoes locally or regionally grown in the mid-Atlantic do not come into season until August. When they’re in season, the quantity pricing is by the bushel and runs $28-$34 a bushel (bushel = 53 pounds) if you can connect directly with a farmer or wholesaler. If you want to can earlier in the summer, Roma tomatoes from Mexico come into season in July and quantity pricing is by the 25 pound box and runs $13/box wholesale (but typically only grocery stores ordering many hundreds of pounds can get this price) or $22/box retail. The bulk retail price represents a discount of 30 cents a pound off the regular retail grocery store price and is offered by the local ethnic grocery stores to consumers purchasing at least 25 pounds at a time.
In addition to the jams and pasta sauce, we also canned salsa. We based our recipe on my brother in law’s (Jeff); our modified recipe that yields 18 pints is shown below. It came out perfectly.
15 cans fire roasted diced tomatoes
6 medium onions, coarsely diced
8-10 habanero peppers, to your spicy taste
3/4 cup minced garlic
5 green chiles, chopped
15-20 T Penzey’s Salsa Seasoning
Saute the onions and garlic until translucent (do not brown). Add in the peppers, chiles, and 6 cups of water. Simmer for 30 minutes. Add the diced tomatoes and Penzey’s seasoning and simmer for 10-15 more minutes until slightly thickened. Add in the juice of the limes to the pot, and using a hand blender, blend salsa to to desired consistency.
Our next canning session will be in Autumn where we will lead a group in preserving apple cinnamon jam, apple pie filling, pear jam, fig and nut conserve, and more.
* ”Clostridium botulinum is a large anaerobic Gram-positive bacillus. When the bacteria are under stress, they develop spores, which are inert. Their natural habitats are in the soil, in the silt that comprises the bottom sediment of streams, lakes and coastal waters and in the ocean, while some types are natural inhabitants of mammalian (e.g., human, cattle, horses) intestinal tracts, and are present in their excreta. The spores can survive in their inert form for many years. The spores require warm temperatures, a protein source and an anaerobic (no oxygen), low-salt, low- acid, low-sugar environment and moisture in order to become active and produce toxin. Improperly preserved food is the most common form of foodborne botulism. Botulinum inhibits the body's production of acetylcholine within the nervous system, the chemical that produces a bridge across synapses, where nerve cell axons and dendrites connect with each other. All forms lead to paralysis that typically starts with the muscles of the face and then spreads towards the limbs. In severe forms, it leads to paralysis of the breathing muscles and causes respiratory failure. Canned goods are required to undergo a "botulinum cook" in a pressure cooker at 121 °C (250 °F) to destroy the spores.” Source: Wikipedia. The acidity of common tomatoes is right on the line between low and medium, and varies with every tomato. Therefore, tomato based products should never be canned using the boiling water method but ALWAYS the pressure canner method in order to destroy botulism spores. Pressure should be at 11 pounds or greater and tomato based products will take at least 20 minutes of cooking at this pressure to ensure the spores are destroyed. If other products (such as onions or other vegetables or meat) are added to the tomato based product then it will take at least x number of minutes of cooking at 11 pounds to ensure the spores are destroyed where x=the time prescribed for the added vegetable with the longest indicated cook time per the USDA. As an extra safety measure one can add acid (such as lemon juice or citric acid) to every jar to increase the acid level (although this often impacts the taste negatively) and/or boil the canned product for at least 10 minutes when it is eventually opened to kill any botulism toxin before eating the product.