Here's a link to the USDA's plant profile to help you with identification, if you're curious.
Here in the Seattle area, salal is everywhere. It's in planting strips, in gardens, growing alongside parking lots and playgrounds and in the parks and woods.
Something I've learned about picking salal: wear rubber gloves (not the kind that are covered in powdered latex). Why? Well, for two reasons. For one thing, as the berries ripen, it becomes difficult to pick them neatly from their stems. Often times, the skin slips off, leaving a rather gross and slippery-slimy berry center mashed all over your fingers. (This is also why I make jelly instead of jam: any remaining stems are filtered out, along with many of the seeds!) The second reason? Well, the berries have a kind of sticky coating on them. After a while, this gunk builds up on your fingertips. After our first year picking salal, I had to scrub my fingers with pumice until they were raw to get the tacky residue off.
So - gloves! Not necessary, but recommended!
As far as process goes, I rinse the berries well, then put them in a pot with enough water to cover by 1-2 inches. I bring the berries and water to a boil, then reduce the heat and simmer until the berries are completely broken down. It can take an hour or two. I leave the lid off the pan and add more water as necessary - so that when I strain my berries, I don't end up with an excess of water in the mix, which would result in a weak-flavoured jelly. While it's cooking, put a small plate or saucer in the freezer for testing your jam later.
When the berries have broken down run them through a food mill. Save the lees and place those on four layers of cheesecloth layered over a fine metal strainer set over a dish to drain. As you gather up the corners of your cheesecloth and wring the mass of the lees tightly, the pressure will force more juice out of the mass than the food mill can get out alone. However, the cheesecloth will keep all the tiny seeds from ending up in your jelly. Combine the juice/puree that resulted from the cheesecloth squeeze and the food mill: this is the base of your jelly. Measure the juice/puree as your pour it back into your cooking pot.
Bring your fruit juice/puree back to a simmer and simmer awhile if the flavour is thin. It probably won't be. Start adding sugar. As a good rule of thumb, I measure the juice/puree before I return it to the pot, and I use the recommended amout of sugar for that much juice/puree according to the instructions on my jar of low-sugar pectin.But I like my jam tart, so I don't add all of the sugar, and I always reserve one cup that I am going to mix the pectin into before adding to the jam.
So. Start sweetening. If you're like me and you like a tart jam (in other words, you're not going to add the full recommended amount of sugar), add 1/2 cup at a time until the flavour is almost where you want it. Stop before it's attained the sweetness you want, when it seems like it is almost as sweet as you'd like - and again, remember that this is a wild berry. There is a tannic earthiness that grounds the finish of what might otherwise be described as a blueberry-and-mint flavour. (It's quite good. Our favorite jam from last year, definitely.) Now is the time to add a bit of fresh lemon juice if you like (I like it with salal, just as I do with huckleberries and blueberries) and taste again. This also reduces the ph of the jelly, making it even safer for home canning.
Measure out your pectin (again, I start with the amount recommended on the box of pectin - about 1 1/2 Tablespoons per 2 cups of juice/puree) and mix the pectin into another 1/2 to 1 cup sugar. Add the pectin/sugar mix to the fruit mixture and stir until dissolved.
Once the pectin is in the mix, it's time to bring the jelly to a boil. Bring to a boil, then reduce to a simmer or a low boil, and pull your saucer or plate out of the freezer. Dribble a couple drops of the hot jelly mix onto the cold plate and wait 30 seconds. Push at the jelly blob with your fingers. If it wipes smooth, keep cooking and try again in a few minutes (and if it's not setting up any better at that point, consider adding more pectin!). If the jelly blob wrinkles over the top, it is ready.
Pour the jelly into sterilized jars and seal according to the manufacturer's instructions for the particular jars you are using. I process mine for 10 minutes, using the boiling water method. More information on the boiling water method and a chart for timing your processing according to altitude can be found here, at the National Center for Food Preservation.
Enjoy! We picked a lot more salal this year, since we did not have enough jars to give to everyone last year. I hope our friends and family are excited to try this wild flavour!