Step 1

1 Empty the packet of Jell-O into a medium mixing bowl

Step 2

2 Heat 1 cup of the cider in a small saucepan over medium-high heat

Step 3

3 Once the cider begins to boil, pour it into the Jell-O in the bowl and stir until all granules have dissolved

Step 4

4 Add the salt, lemon juice and the remaining 1 cup of cold cider, stirring to combine

Step 5

5 Refrigerate for 1 to 1 1/2 hours

Step 6

6 Cut enough of the celery into 1/4-inch dice to yield about 1 cup

Step 7

7 Use the large holes of a box grater to grate enough of the apples, including the peel, to yield about 1 cup

Step 8

8 Begin checking the refrigerated gelatin after 1 hour

Step 9

9 When it is thick but has not set, stir in the apples and celery, mixing to distribute them evenly

Step 10

10 The gelatin should be just firm enough so that the apples and celery don't sink to the bottom

Step 11

11 Spray an 8- or 9-inch square pan with cooking oil spray

Step 12

12 Transfer the mixture to the pan, cover the pan with plastic wrap and refrigerate for at least 2 hours

Step 13

13 Serve cold, with a small dollop of mayonnaise, if desired

Step 14

14 NOTE: To double the recipe for molding, dissolve 2 packets of Jell-O in 2 cups of boiling cider, then add 1 3/4 cups of cold cider; the gelatin will be sturdier and will hold its shape better after unmolding

Step 15

15 Spray the mold with cooking oil spray before fillng

Step 16

16 To unmold, use a moistened fingertip to gently pull the gelatin away from the side of the filled mold

Step 17

17 Dip the mold into warm water up to the rim for 10 seconds

Step 18

18 Wipe the mold dry and give it a shake to loosen

Step 19

19 Moisten a cold serving plate and invert it over the open end of the mold; hold plate and mold together firmly, and invert both so that the Jell-O plops satisfyingly onto the plate