My Grandma Williams makes delicious grape juice every year, so this year I decided I would get her to teach me how to do it. Then I got engaged, and thought that it might be a good idea to make enough for the whole wedding!
We did two bushels (giant baskets) worth of concord grapes from Honey Valley Farm in Jordan. First step was to sanitize the mason jars by putting them through the dishwasher, and washing and pouring boiling water over the lids/sealers.
The most tedious part of the process was de-stemming the grapes (or de-graping the stems) after washing them of course. Thankfully my mom came along to help! This part's a little messy; I had purple fingernails for a few days after.
Next we put the grapes in the triple boiler- the bottom portion has boiling water in it, the middle is where the juice drips, and the top is where you put the grapes and sugar. We added about a cup of sugar and a bunch of grapes to the top part. As it heats, the juice drips into the middle portion. It's not a hard process, just tedious.
Now the hard part: waiting. You have to wait for the juice to drip down. When there's enough, it starts to fill up the tube, and you can empty it into your mason jars. But be careful, because they're hot! As soon as the jar is full, you can screw on the lid with some oven mitts. You have to make sure that there isn't any cold water on the outside of the jars, because if there is, the jar could snap. My grandma had newspaper set out to put the jars on in case there was any water droplets.
As you're waiting for the juice to boil down, you should just make sure that there is always water in the bottom of the boiler, or else you could burn a hole in the pan! You can refill it with boiling water from a kettle. After a while, all the juice is out of the grapes, and just the skins and seeds are left in the top. You can throw them out and add some more grapes.