How To Make Easy Fruit Jams and Reductions With A Crock Pot


Fruit jam and reductions serve different purposes in baking, but they’re both easy to make yourself if you want the best flavor. You make them in basically the same way, but reductions are used to get a stronger fruit flavor in fillings and icing.

They can both be made by cooking the fruit, or you can do it this slower way in a crock pot if you don’t need them right away.


Easy fruit jam and reductions in a crock pot

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How to make a fruit reduction with a crock pot.

Fruit reductions are great for flavoring icings and cakes, but they’re a pain to make. 

They’re similar to citrus curd as a flavoring, but you have to stir them as they reduce to avoid hot spots that can burn the fruit.

I personally don’t enjoy being trapped stirring a pot so that things don’t burn.

I had a bag of frozen raspberries that I had been planning on boiling until they were pulp, but then I came across the crock pot method. 


fruit reduction in a crock pot

This is obviously not something that you can do quickly, but if you’re planning ahead then it works really well.

All you do is put the fruit into the crock pot and mash it up, then turn it on low and leave the top off. 

The low heat will evaporate the liquid from the fruit, and if the lid isn’t on the pot it will thicken to a jam-like consistency.

Since raspberries have a lot of seeds, I took them out of the pot after they had been cooking for a while and strained as much out as I could by using a sieve. 

I used a 2-quart crock pot for this because it was a small amount of fruit. You can get a crock pot in most stores that sell home goods, or here on Amazon: Crock Pots



straining the fruit

I was afraid that there wouldn’t be anything left other than the juice after I did that, but there was still pulp in it.

Depending on what fruit you’re using, you should remove them from the pot after about three hours or so and mash them up. 

This is generally true for firmer fruits like apples or pears, while berries might not need that step. 

Firmer fruits will probably require some water in the pot to begin with, and the softening up process will probably be sped up by leaving the top of the pot on.

After mashing or straining the fruit, return it to the crock pot and heat it on low again, but stir it every 20 minutes at least. 

It will get thicker, and when it’s the consistency of a jam it’s ready. Remove it from the pot and refrigerate.


finished fruit reduction

This isn’t a sweetened recipe, so it’s not going to be good to eat straight out of the pot. 

Use it to flavor meringue buttercreams, cake batters or other baked goods. 

If you want to do a sweetened version add some sugar or other sweetener to taste after it’s reduced to the thickness that you want.

This really does reduce the fruit A LOT. 

From one bag of frozen raspberries (I think it was about 10 oz) I got about 3 Tbsp of fruit reduction. With a very, very concentrated flavor!

For another article about using fresh fruit inside of a cake without ruining the cake structure, click here.


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How to make fruit jam in a crock pot.

Fruit jam can be used for fillings in cakes or as a topping on cheesecakes. You can also eat jam with toast, of course!.


figs in a bowl

A couple of years ago I planted fig trees in our backyard, and the first year that we really got a lot of figs, we ate them until there were too many being produced on a daily basis to do that, and we started making jam.

The first thing I did was cook them the “right” way, but that reminded me of how much I hate cooking things in sugar that need to be stirred constantly.

It’s not hard to do, but I decided to do the next batch in a crock pot because I don’t enjoy getting burned by hot sugar when it spurts out of the pan when the bubbles burst.

And when you don’t stir it constantly, it will heat up in the center of the pan and explode when you do stir it again. I’m not kidding, be careful, because hot sugar is REALLY HOT.


cut-up figs in a crock pot

So the next round of figs were cut up in little pieces and put into the crock pot.


cut-up figs in a crock pot with sugar on them

I added the sugar and THAT’S ALL. And I even reduced the amount of sugar that I put in, because it didn’t need to be that sweet.

Most jam recipes call for fruit and sugar in equal amounts, but I put about 1/3 of sugar in, and no added liquids.

When you’re cooking sugar, you’re basically evaporating the water that’s in the sugar, and adding water to it first only slows down the cooking process so that you can control it better.

If you’re doing this in a crock pot adding a lot of liquid (meaning the “normal” amount in most recipes) will only slow down the reduction process, which is basically what you’re doing.

Adding less sugar and no liquids lets the flavor of the fruit really come out, and it speeds up the crock pot reduction process because there’s less liquid to evaporate.

So the recipe for this was basically 1 pound of fruit and 1/3 cup of sugar, but you can adjust that based on how sweet the fruit is and how tart you want the final product to be.


mashing the fruit and sugar with a potato masher.

So with the figs in there, and the sugar added, I mashed it all up really well using a potato masher.

You want the fruit to be really smashed so that the cooking is sped up, but if you like jam that has chunks of fruit in it, leave some unmashed.

If you’re using fruit that has a lot of seeds like raspberries or blackberries, you might want to strain those like the reduction recipe above.

And if the fruit is harder, like apples, and can’t be mashed, you might want to cook them first to soften them up. If you don’t want to do that, you should just cut them into REALLY small pieces, add liquid to the mix, then mash them after a few hours when they’ve softened up.


crock pot with mased up fruit inside

When everything is mashed up, turn the crock pot on high and leave the lid off.

Depending on how full the pot is, the cooking is going to take anywhere from 5 hours to 12, but you don’t really need to pay much attention to it.

As the fruit heats up, the temperature will go up faster because the liquid will evaporate, so after a few hours you should start watching the pot to see if it looks thick enough.

Stir it occasionally using a rubber spatula to make sure that it’s thickening up evenly.

If you want to test it you can put a plate in the freezer to drop some of the hot jam on. When the jam cools off you’ll be able to see how thick it is, and if it’s still runnier than you want it, just let it cook longer.

You can use a candy thermometer for this, but I just look at it and make a call about when it looks right.


Fig jam on a piece of bread

When it’s done, store it in a container in the fridge for up to two months, but it probably won’t last that long. You can also freeze it for up to a year, but it should definitely be stored cold because this process isn’t a true canning process for putting preserves up in dry storage.

You can use these preserves for cake fillings or as a topping on cheesecakes, or for filling in turnovers or other types of pastries.


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