A Mathematical Formula for Jam/Jelly/Marmalade

I’ve been canning for over 20 years.  I went through a lot of trial and error the first few years as I tried different recipes and combinations.  At one point I realized that all the recipes were crap, so I threw them out and just used my own.  I actually came up with a simple formula for fruit jams and marmalades that work very well with any combination of fruit and juice.  In the most recent years I began replacing the juice with wine in some batches, and that has yielded some fantastic results as well!


Before you get all excited and run to the store for fruit, it’s important that you first gear up.  Staples in my kitchen include:


Blender – because I’m lazy efficient

2 large stock pots – one for cooking, one for water bath

Wooden or bamboo spoon

Large ladle – big but not that big

Wide mouth funnel – the ones made for canning

Jar tongs – trust me, you don’t want to burn your skin handling the hot jars


Each batch of jam will make 9 half-pint jars, or 4.5 pin jars (please don’t double batches, trust me).  If you’re reusing jars, you can reuse the ring part of the lid but not the flat part of the lid.  Luckily you can purchase these flat lids in replacement sets.  Sanitize the jars and lids right before making jam.  The more sanitary, the longer the shelf life.




Any time you make a batch of preserves, have lemon juice and stick butter on hand.  I add a table spoon of lemon in each batch for acidity.  And a tablespoon of butter in each batch keeps the froth from getting out of control.  I tend to buy frozen fruit for jam.  Frozen fruit is flash frozen when it’s just under-ripe.  Since cooking fruit will ripen it, under-ripe fruit is perfect for the job.  We have a fig tree that has been very productive lately, and we pick the figs just before they fully ripen.


A bit on procedure… This is already simple so I don’t recommend cutting any corners.  Cook fruit, add sugar, cook come more, ladle into hot jars, seal jars, 10 minute water bath, let cool/congeal at room temperature for at least 24 hours.  Ok, here we go!



Fruit Jam (Mixed Berry Jam, Strawberry Jam, Blueberry Jam, etc.)

Marmalade (Peach-Orange Marmalade, Cranberry Marmalade, etc.)

Wine Jam (Fig Tempranillo Jam, Blueberry Cabernet Jam, etc.)


5 cups fruit

~2.5 cups juice (apple juice or wine for jam, orange juice for marmalade)

1 tablespoon lemon juice

1 tablespoon stick butter

1 box powdered pectin

7 cups of sugar (don’t freak out, it’s not that big a deal)


Fill blender to the 5 cup line with fruit (cut or quartered).  Fill juice to the 5 cup line.  Add lemon juice, butter, and pectin.  Blend.  Pour into stockpot and heat on high to boiling.  At the first boiling point, add sugar and stir until all sugar is dissolved.  Continue to stir until mixture reaches a rolling boil.  Let mixture boil for 90 seconds (this is critical).  Remove from heat and ladle into sanitized jars.  Seal.  Boil sealed jars in water bath for 10 minutes.  Set out on counter to cool for 24 hours.


Yields: 9 cups (9 half pint jars or 4.5 pint jars)


Note: Wine can be substituted for juice.  I would recommend pairing fruit with wine that  go well together.  For example – fig with Spanish red wine, strawberry with moscato or white zinfandel, blueberry with cabernet, etc.  If you use champagne or any sparkling wine, open the wine and let it go flat for 24 hours before using.  If you don’t let the bubbles out before canning, they’ll come out after you’ve sealed the jars, and you’ve just ruined the batch.  Let’s not waste wine, ok?




After about 24 hours when the jars have naturally cooled to room temperature, you can dress them up with labels, ribbon, fabric, and/or twine.  I always wait and make sure I’ve gotten a good seal on all jars.  If none of the lids pop when you press down on them, it’s ok to unscrew the lid and add fabric.  If any of the lids pop, the jar isn’t ruined, you just need to replace the flat lid and redo the 10 minute water bath.


I hope you all have fun with this, and please let me know how your batches turn out!


Up next: Pepper Jelly and Cranberry Sauce and Pumpkin Butter, Oh My!


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