Red Currant Jelly

I started with probably 5 pounds of frozen currants (because Catherine and I missed the season for fresh currants). My estimate may be off on the quantity. 
The berries filled 2 large Ziploc bags. The yield was 5 small Weck canning jars full of jelly. I think they hold about 6-7 ounces each.

I cooked the berries in 2 batches using my enamel lined cast iron dutch oven. Cook the berries for maybe about 15-20 minutes, squashing the berries as they cook. I didn't add water.
Place a colander in a shallow bowl or non-reactive pan lined with 2-3 layers of cheese cloth (hold the edge with clothes pins or whatever clips to keep the cheese cloth in place. Ladle the mashed berries into the cheese cloth and allow to drain, undisturbed for about 3 hours or over night. I had 4 cups of juice from both batches. If you try to force the juice out of the cheese cloth, the jelly may be cloudy, so don't squeeze the cheese cloth or crush with a spoon. Just wait. Yes, it's wasteful.

Measure the resulting juice into a non-reactive pan and add sugar in equal amount. 

Cook, on high heat, stirring often. Watch carefully as the syrup will foam up, so you will need to adjust heat to settle it. I did the spoon drip test after about 15 minutes, and wasn't confident that it was done. I let it sit for a few minutes and painstakingly skimmed the foam from the surface. I used a fine tea strainer. I decided to cook it further so returned it to a boil and cooked it about 5 more minutes and concluded it had hit the jell stage. So I think the timing is about 20-25 minutes of boiling the syrup before it set. 

The spoon test: With a large metal spoon, clean off any scum from the edge of the spoon. Hold the spoon about 18 inches above the syrup and allow dripping from the edge, At first it will be a stream, then single drips, as it cooks, the syrup will drop a "sticky" drip and eventually 2 drips, then a sort of curtain of syrup will drop off the spoon. That means it's going to jell. Stop cooking at this point. 

I processed in the boiling water bath for 5 minutes in sterile jars.

Processing:

Boil clean jars, lids and seals in a large roaster or stock pot or canner for about 5 minutes. Remove with tongs and drain on a clean towel.

When jelly is cooked, ladle into jars, leaving 1/4 inch head space then wipe the rims of the jars with a clean, wet towel to enable a good seal. Place lids on jars, with seals attached. Add clips and fully immerse the sealed jars in the pre-heated canning bath. Use tongs. Bring to the boil, wait 5 minutes, then cut the heat and carefully remove the jars from the bath with tongs. Allow to cool. Remove clips and test lids. They should stay put if you lift the jar by the lid. Do not tug on the rubber rings until you are ready to use the jelly. 

Should keep indefinitely until the seal is broken. Then refrigerate. 

Note: air will escape from the jars during the canning. This is normal. 

-K