I used to make single eggs for steelhead fishing back in Ontario.
You need to test them with a hook every couple of minutes when boiling them to get the right amount of hardness.
Too little and the just pop and leak, too much and they will just split.
There are other ways to make singles but that will have to wait until I can dig them up. 8)
Digging done!!!
Here are a couple more ways of curing single eggs.
1/ Water harden eggs and allow to drain and fridge dry for up to two hours (they might wrinkle). Dissolve one tablespoon of boric acid crystals per litre of water. Add dried eggs and stir. Allow eggs to absorb the solution for about one hour and to plump up. Test by squeezing with your fingers. They should be firm and rubbery. If eggs pop, soak them longer in the solution. They can be refrigerated or frozen in baby-food jars.
Unfrozen eggs will last up to 6 months in the fridge, years frozen. They have natural appearance and colour, and done properly you can pierce them with a hook and they'll slowly leach out scent. Experimentation is required to get eggs to the right hardness.
2/ 1 tablespoon of crystal Drano to 1 litre of water. Add food
colouring [optional]. Usually takes about 10 minutes for roe to cure, but
continually check with the point of a hook until desired consistency is
reached. Immediately rinse with water. Keeps in fridge for about 2 to 3
weeks, seemingly forever when vacuum-packed in the freezer.
