Presto makes a 3-piece adjustable weight that can “convert” your Presto Gauge Pressure Canner into a dual-gauge pressure canner, like the All-American.
It’s a 3-piece weight that adjusts easily to 5, 10 and 15 lbs of pressure; the Presto part number is 50332.
This 3-piece weight is only designed for use with a Presto. If you have a different make of pressure canner, you need to look for a weight made specially for that.
The cost is about 12 bucks US (as of spring 2015), and it will change your life.
The default weight that ships with the Prestos is 15 lbs, which is really only good for people at very high altitudes. For those people, it will be accurate as a rocker in the range of 15 to 16 lbs, but for everyone else, it’s just a counter-weight there to hold all the pressure in, with the added feature of its being able to move should it need to for way over-pressure safety purposes. You have to stand in front of the stove and watch the gauge constantly and fiddle with the burner constantly to maintain the correct pressure.
With the adjustable 3-piece weight, you no longer need to sit in front of the stove watching the gauge like a hawk, or, get your gauge tested yearly. Just adjust the heat so that this weight rocks constantly.
The weight is a 3-piece set: 1 spindle, with 2 detachable rings that stack on the spindle. The spindle by itself is 5 lbs weight. Each ring is an additional 5 lbs. So if put 1 ring on the spindle, it will be 10 lbs. With both rings on, it will be 15 lbs.
To detach the weights; you just pull up on a ring. They are somewhat snug at first but will come off; just pull up. To put back on, just set a ring over the spindle and press it down.
The spindle has a black wood knob that screws off, but you really don’t need to.
It rocks gently and constantly while the machine is use to release excess pressure.
This weight effectively keeps the machine at ½ lb or a lb over the pressure target, because what it does is release excess pressure over the amount selected (by the rings.) So when you have 10 lbs indicated on the weight, the machine will actually reach 10.5 or 11 lbs, at which point this rocker releases the excess pressure.
This 3-piece weight works with more current models of presto; it won’t work with many of the older models of Presto. [ The issue with older Presto models is that it won’t fit the older design of the vent pipe. And the vent pipe that would fit it, can have different size screw threads from the older canner lids, so that’s a no go, too. ]
For instance, it will work with:
- 16 quart gauge model (01755);
- 16 quart weight model (01745);
- 18 quart gauge model (01751);
- 22 quart gauge model (017800x);
- 23 quart gauge model (01781);
- 23 quart gauge induction-compatible model (01784).
When you get the 3-piece adjustable weight, simply take the 15 lb weight that came with the machine, file it away in a drawer, and use the adjustable one in its place over top the steam vent. Have the right number of rings on for your altitude. Remember, the spindle and handle itself counts as the first 5 pounds.
The rocker weight doesn’t screw onto the machine top; it just rests on: it has to be free moving to rock.
You just ignore the gauge completely and depend on the weight alone. The gauge just becomes a handy visual reminder or backup check (that may or may not be accurate as time goes by — note that in the insert that comes with the weight, Presto does say, “do not compare or rely on the dial gauge.”)
The regulator begins to rock “when the selected pressure is reached inside the canner. The heat should be adjusted to keep the weight rocking gently throughout the entire process. You learn to trust the sound of the weights.
You don’t want the weight to rock with violent, steam-engine rocking. That is a waste of energy in terms of money, but in terms of processing it can mean that you will run out of water inside the canner way too soon and run into pressure changes that cause liquid loss in your jars. If the heat source is not sufficient, it will stop rocking and you need to increase heat *and* start processing time all over again from the start of the time.  National Center for Home Food Preservation Self Study Course. Module 4. Canning Low Acid Foods: Dial Gauge Canners. Accessed March 2015. You want a very gentle, steady rocking. As long as it is rocking gently you have the correct pressure and temperature. So lower the heat as far as you can go while still maintaining that gentle rocking. It’s more energy efficient, and you’ll get a better, more efficient processing with no worries about boiling the water dry.
This video is from Presto, showing an optimal rock.
For higher altitude people, the decision to use a weight can be problematic. Your altitude may only require 12 lbs pressure, but the weights only allow an increase over that of 15 lbs. Some people feel that can result in over processing, and for that reason they prefer to use and watch a gauge which can deliver 12 lbs.
Why no weights between 10 and 15 lbs?
Many beginners often ask the question that older canners forget to ask: why are there no weights available in between 10 and 15 lbs?
We don’t know the answer, but it is a very good question: why, historically, did weighted gauge pressure canner makers decide to only offer 5, 10 and 15 lb weights, while other forms of pressure cookers / canners offer a weight such as 10.5, 11, 12, as well?
We don’t know but have put the question on the research list.
Some people take matters into their own hands by making this 3-piece weight into a weight that covers weights between 10 and 15 pounds. The theory is to use the spindle with one of the 5 lb weight rings to give you 10 lbs, and then find a washer or a combination of washers that weighs ½ the weight of a 5 lb ring, and put those onto the spindle. To test your work, people then say to do a dry run or two canning just water to see if your gauge (if it’s properly regulated, presumably) confirms that the correct pressure is being achieved and regulated.
The above should not be construed as a recommendation or endorsement from healthycanning.com; this is just an FYI. We addressed the issue just in the interest of thoroughness because it is out there.
USDA directions on weighted gauge allow only a choice between 5lb, 10 lb and 15 lb, and currently have no provision for pressure in between when pressure is regulated by a weight. We adhere to USDA guidelines and so support only those pressures.
We have not heard of anyone regretting getting the 3 piece; the only regret that seems to ever be heard is that they didn’t get it right at the very start with the machine. If anything, you’ll hear complaints of people wondering why on earth it isn’t included with the canner, even if Presto had to charge a few dollars extra.
If you treat yourself to one thing this year, we’d suggest this be on the consideration list.
Again, the Presto part number for their 3-piece weight is: 50332.
Good luck and happy rocking.
Here’s an Amazon link. Amazon links change over time and they don’t give anyone any notice. Make sure you buy the 3-piece one with Presto part number 50332. Ask someone on Amazon if you have to before buying, and though price varies by phase of the moon on Amazon, you should never have to pay more than 15 to 30 dollars (depending on your country) for it at the very very most! If you see it costing more than that, keep searching, cheaper will turn up.
Presto Pressure Canner Topics
|↑1||National Center for Home Food Preservation Self Study Course. Module 4. Canning Low Acid Foods: Dial Gauge Canners. Accessed March 2015.|