Tag: Tomatoes

Open faced sandwiches with fresh tomatoes

Now is the time of year to make our favorite fresh tomato sandwich: open faced with tomatoes, bacon and cheese. But you don’t have to wait for the big main crop tomatoes to ripen (our first one will come in tomorrow). Instead, you will find that smaller tomatoes have a richer flavor.

Our smaller tomatoes this year include Fourth of July, which always comes in first (July 17 this year), Garden Gem (from Prof Harry Klee’s breeding lab in Florida), Indigo Rose, Mountain Magic, Garden Treasure and one early plum variety: Gladiator.

The main trick to making these sandwiches is to put the bacon over the tomatoes, but under the cheese, so it doesn’t burn when put under the broiler.

6 slices bacon
4 sliced bread
Butter
Sliced tomatoes
Sliced cheddar ( we use Cabot)

Fry the bacon slices until rather crisp
Toast the bread and butter it.
Arrange the sliced tomatoes on each piece of toast
Put 3 half slices of bacon over the tomatoes.
Put the cheese slices over the bacon

Broil the sandwiches for 2-4 minutes, until the cheese begins to melt.

Serve at once.

Why add lemon juice when canning tomato sauce?

When I published my article on making tomato sauce with the assistance of the Instant Pot, a number of people commented that I had left out the lemon juice. They referred me to this slightly misinformed warning article. More to the point, the USDA recommends adding 1 Tb of lemon juice per pint of sauce.

In fact, the USDA, on a site hosted by the University of Georgia, explains that the pH of canned tomato sauce must be at or below 4.6 to prevent the growth of botulism. This sounds like really good advice, but we have been canning tomato sauce for over 30 years without adding lemon juice, and no one has had any ill effects.

The pH value is a measure of the acidity of a solution, here of tomato juice, and the lower the pH the higher the acidity. Thus foods having a pH of 4 are more acidic than those with a pH of 5. This Is a logarithmic scale, so foods with a pH of 4 are ten times as acidic as those with a pH of 5.

So we decided to look into this a little further. It turns out that we aren’t the first. The University of North Dakota Ag Extension in 2007 looked into the pH of a number of popular tomato varieties that you might use in making salsa. They measured the pH of the tomatoes, of the salsa and of the salsa with lemon juice, and found that only the salsas with added lemon juice had a pH below 4.6. These were grown in Williston, ND and probably in a greenhouse, so the pH values might differ from the garden and in warmer states.

More recently, in 2010 Heflebower and Washburn at Utah State measured the acidity of juice from a number of popular varieties, including Celebrity and Rutgers, finding that the pH varied from 3.92 to 4.32. Clearly sauce from these varieties need not be further acidified. They also found that pH didn’t vary much based on maturity of the fruit, nor on whether a new or an heirloom variety was tested. However, since tomato sauce may vary with the mixture of fruits you use as well as the weather conditions, they suggest that it would not be unwise to continue to add lemon juice.

However, since 2010, there have been a number of tomato varieties bred especially for flavor, and we decided to test the pH of the 8 varieties growing in our garden. We used a THZY portable pH meter, calibrated with the supplied buffer solution. We squeezed juice out of part of each tomato and filtered it through a coffee filter into a freshly washed glass, rinsed with distilled water.

Here are our pH readings

Opalka *	4.62
Lemon Boy	4.45
Garden Gem **	4.30
Amish Paste *	4.14
Fourth of July	4.14
Better Boy	4.11
Cloudy Day	4.11
Garden Treasure **	3.91

* Heirloom
** Recently developed

The Opalka variety has been a reliable paste tomato for years, but obviously if you use it, you must add lemon juice to your sauce. If it is only one of many, you may not need to. Note that Lemon Boy, a mild yellow tomato is the only other one even close to a pH of 4.6.

Professor Klee at the University of Florida developed the Garden Gem and Garden Treasure varieties (**) with significantly a improved taste, and we recommend them highly.

What about the sauce?

The pH of the final sauce will be influenced by the ingredients you add: in our case onions and spices. We tested the pH of sauce from 2015 and from last week. They were 4.18 and 4.33 respectively, and thus perfectly safe. Interestingly, it was the 2015 sauce that used Opalkas. This year they haven’t done well and none was in last week’s batch.

Conclusions

You would probably be safe without adding lemon juice, but a tablespoon of lemon juice will make a substantial change in the pH and in your safety. We found that adding a tablespoon of lemon juice to a pint of distilled water reduced its pH from 5.86 to 2.96. Thr scientists at the University of North Dakota found that the lemon juice reduced the pH of salsa by only 0.3 pH units. And don’t worry about the possible sourness: one or two teaspoons of sugar will easily cancel it out. In the batch we made yesterday, we added 1 Tb of lemon juice and 1 tsp of sugar to the bottom of each pint jat.

What is pH? [a sidebar]

The concentration of acid, or specifically of hydrogen ions (H⁺) in a water solution can vary from 10⁰ (or 1.0) to 10^-14. Since this is hard to write down, we usually refer to the concentration by the exponent of 10 or 0 to -14. And, in order to make this more convenient we remove the minus sign, so pH values run from 0 to 14. Neutral pH (neither acidic nor basic) is pH 7, where the concentration of hydrogen ions and hydroxyl ions (OH^–) are equal.

So if we want to write down the acid concentration equivalent to a ph of 4.6, that means 10^-4.6 and that is the same as.00002512.

And what are the units of this concentration? It is moles per liter, where a mole is the molecular weight of an element in grams. A gram of hydrogen ions (or of hydrogen itself for that matter) is one mole. It turns out that a mole of any element or compound has the same number of particles (ion, atoms or molecules) and that number is called Avogadro’s number. While Avogadro proposed it, it was first calculated by Loschmidt to be 6.02 x 10²³ particles.

Tomato sauce in an Instant Pot

A lot of recipes for the Instant Pot pressure cooker are just faster ways of doing the same thing, and add only a little advantage. We have found that you can not only make tomato sauce well in the Instant Pot, it’s a lot more efficient both in time and dishes used!

Previously, we made tomato sauce by cutting up the tomatoes into halves or quarters and then chopping them in a food processor. Then we cooked the sauce until all the pieces of tomato had softened before running it through a food mill to remove the skins and seeds. Then we cooked the resulting sauce with added spices until thickened.

The Instant Pot method is much simpler. Just cut the tomatoes in half or quarters and toss them into the instant Pot. Since the tomatoes collapse as they are pressure cooked, you can fill the pot right to the max if you have that many tomatoes. We didn’t have that many yet so our pot was really only loosely 2/3 full. We weighed about 4.2 lbs of tomatoes in this first run.

Then pressure cook them for about 20 minutes. We first tried 10 minutes and they weren’t quite soft enough, so we added 15 more. Probably 20 would have been plenty. Since the tomatoes in the pot are mostly in their own water and not near the steam release spout, you can safely use Quick Release. But letting the pot cool naturally won’t hurt anything.

Then, place a food mill over another pot (sorry you still have to get two pots dirty) and scoop out the tomatoes. They should mush up quickly in the food mill and go through to the pot below. The skins and seeds remain behind.

Add the following to the sauce in the pot. The amounts depend on your taste and the batch size.

1 Tb salt
1 Tb sugar
1 minced onion
2-3 Tb chopped parsley
2 bay leaves
2 Tb chopped basil
1 Tb oregano
lemon juice (1 Tb per jar)

Cook until the sauce has thickened, about 30-40 minutes.

Sterilize mason jars and new lids in a pot of boiling water for 15 minutes. Drain them on a paper towel, add 1 Tb of lemon juice or 1/4 tsp citric acid, and then immediate fill with hot sauce. Wipe off the rims to make sure the lids will seal. Put on the lids and screw them down.

Put the jars back in the boiling water and sterilize for 30 minutes. Remove the jars and let them cool, Make sure each lid “pops” and is concave.

Now, while we didn’t have quite a full pot of tomatoes this time, we will soon. In fact, we usually can about 10 lbs at a time, and in this system, we would make one batch, run it through the food mill and then do another batch and run it through the food mill, and cook and can both batches of sauce at once. That’s way easier than the “old” way!

Fresh tomatoes: open faced sandwiches

Now that tomatoes have finally started to ripen, we can make our favorite summer sandwich, the toasted open faced sandwich. You could make them any time of year, but fresh garden tomatoes or equivalent ones from a farmer’s market are best. You want the flavorful kind of tomatoes that are raised locally as opposed to those bred to ship.

Fourth of July

Amish Paste

Opalka

Clloudy day

In our Connecticut garden, our favorite early tomato is Fourth of July, which was bred from cherry tomatoes. It’s growth habit forms clusters of smallish tomatoes, but way bigger than actual cherry tomatoes. We also find that our paste tomatoes begin to ripen fairly soon thereafter we are growing Amish Paste and Opalka this year. Finally, the Burpee Cloudy Day variety is the first full-sized tomato to ripen: it’s one you can slice for sandwiches. It’s also blight resistant.

If you can slice up a combination of these types to make a few sandwiches, you are ready to make open faced sandwiches. We start by lightly toasting the bread and buttering the toast lightly. Then we lay on the slices of tomatoes, about one layer or so thick.

Then we put on strips of fairly crisp-cooked bacon, and top with slices of sharp cheddar cheese. This order is important. For stability, the tomatoes have to go first, and put putting the bacon under the cheese, you prevent it from burning in the broiler.

The final step is, of course, to slip the open sandwiches under a broiler for a few minutes. This doesn’t take very long, so watch carefully. You want the cheese to melt, but don’t want anything to burn.

Serve immediately. It’s OK to use a knife and fork on these delicious sandwiches.