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Fresh Rhubarb Pie - best thickener?

  • b

Today I made a fresh rhubarb pie. After it had thoroughly cooled my husband and I had a nice cup of tea and cut into the delicious looking pie. Everything was perfect except the filling. It was very very soupy. I have always had trouble thickening fruit pies. I used sugar, flour and 1 egg in the filling for this pie. What do you use to thicken a fruit pie? Do you find that cornstarch, or tapioca is better than flour? I am going to make another one probably tomorrow and I will try a different recipe. Any tips would be appreciated.

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  1. My mom swears by tapioca in her rhubarb pies - man, you just made my mouth water. I haven't been home during rhubarb season since I can't remember when....

    2 Replies
    1. re: schoenick

      Even though the pie was kind of soupy, boy did it taste good!! I am lucky to have a small rhubarb patch in my garden.

      1. re: schoenick

        It is what I always use. Minute Tapioca for juicy fruit pies. When peach season comes I am going to try grinding it to fine powder. I have occasionally have had the tapioca not completely dissolve,

      2. I'm getting cranked up about potato starch, though for health reasons I have to go easy with it. Besides being a great starch for coating fried foods, it's a wonderful thickener, since it dissolves even in cold water. I have not tried it as a pie thickener yet, but as the stone-fruit crop is supposed to be brilliant this year I'm sure I'll get lots of practice!

        4 Replies
          1. re: smartie

            I prefer Minute Tapoica for very juicy pies as rhubarb tends to be. If yo are going to try arrowroot be aware it loses it's thickening power if it cooks too long. So in a rhubarb pie unless you cook the filling first and then add the arrowroot just before pouring into the crust you can end up with a soupier pie than you started out with.

            1. re: Candy

              Candy, how long do you have before arrowroot goes soupy? I've never had that happen, but I also don't usually bake pies or cobblers slowly at low heat.

              1. re: amyzan

                Actually very little time. Once it comes to a boil it will start to lose thickneing power. It is not a thickeneing agent I would use for pastry

        1. I like cornstarch for rhubarb, but flour is fine. The egg is a liquid which, given normal proportions, would make the filling somewhat creamy. You don't need it. Rhubarb is low in pectin. Add a little lemon, which will aid the gel.

          1 Reply
          1. re: janeer

            I also would have said you do not need the egg. As 'janeer' said, "add a little lemon," and just a touch of flour - maybe even dredging/mixing the rhubarb in the flour as we do with blueberry pie. I'm still harvesting rhubarb from my garden, a few stalks every night, here in New England. Love it!!

          2. I would use arrowroot or tapioca flour, mixed in with the sugar, then sprinkle lemon juice over the filling once it's in the shell. I've never used an egg in rhubarb pie filling, don't know why you'd need that or how it would contribute? It's also good to let them cool thoroughly before cutting into them, very hard to wait! Congrats on your rhubarb patch! I only have one plant left from five I planted several years ago. They don't seem to like the extreme temperatures here.

            1. My mom swears by arrowroot, but in a pinch I've recently used both sweet rice flour (mochiko) and kudzu flour, both with good results. (All three have a relatively "neutral" taste, unlike cornstarch, and don't get gummy like wheat flour)

              1. I always use cornstarch for fruit pies, but any of the alternative starches mentioned here should work fine.

                1. I prefer cornstarch rather than flour. Though I know there are scientific differences, the main reason I like it is because of the appearance. It produces a much more glossy finish than flour, which finishes rather cloudy. I know tapioca is also good, but am not that familiar with it. Whatever you do, don't buy those "mystery" thickeners that some sort of gloppy, already thickened, flavored something that comes in a plastic "sleeve". The Amish around this part of the country use them all the time, and have come to use mostly thickener and very little fruit in their pies. Beware when you come to Lancaster County PA looking for all that "wonderful" Amish food!

                  1. Guess I didn't find it on this thead, but awhile back someone here recommended using one box of Strawberry Jello powder to thicken Rhubarb Pie. I can't imagine using anything else now!

                    1. I have twice now made the most perfect rhubarb pie from the recipe in Micheal Rhulman's 'Ratio'

                      1 1/2 lbs. rhubarb, about 5 cups sliced rhubarb (chopped lengthwise first if stalk is very large/wide
                      12 oz. granulated sugar - 1 1/2 cups
                      1/3 cup cornstarch
                      He calls for tsp of cinnamon, and a pinch of cloves; I prefer 1/2 tsp. cinnamon and 1/2 tsp. cardammom - + a pinch of salt.

                      Toss all together and put in bottom crust, then make a lattice crust for the top. I put a little sugar in the raw on the lattice for texture.

                      People who have eaten this pie have commented that it had the perfect texture, thick, without being gummy, and the rhubarb taste really shines through. I agree.... will probably make it again this weekend!

                      3 Replies
                      1. re: gingershelley

                        gs your pie looks picture perfect!

                        Have you cooked much from Ratio? I picked it up for a song at a thrift shop but haven't even looked at it yet. Your post, well...your amazing pie, has reminded me I need to remedy that. If you've tried other recipes you'd recommend, I'd love to hear about them. I really enjoy Rhulman's writing style and especially enjoyed The Soul of a Chef.

                        1. re: Breadcrumbs

                          BC, yes - I quite like the book. It has helped me be able to make more things from memory, which I really like; the idea being when you know the ratio for something, you can make it without needing a recipe, and can also increase or decrease quantity just sticking with the ratio.

                          Pie Crust, Paté a choux, custard sauce or custard so far are the ones I have gotten down. More to commit to memory in the future I am sure:)

                        2. re: gingershelley

                          That looks amazing, but that's a lot of sugar in the filling! When I make my rhubarb crisps/pies etc, I'm usually using 1 cup of sugar for every 7 cups of chopped rhubarb! I do like rhubarb pies that are on the tart side. 1.5 cups of sugar for 5 cups of rhubarb is definitely on the sweet side. ;-)

                        3. Ever had a rhubarb custard pie? It's a really great balance of sweet and sour and sets up nicely.

                          About 2 cups sugar (depending on how sourness of your rhubarb)
                          6T flour
                          1/2 t salt

                          Add to the dry:

                          4 eggs, beaten
                          1/4 c whole milk
                          1 t vanilla

                          Pour the custard over about 6 cups diced rhubarb in a prepared raw pie shell, cover with a lattice, if you like, and bake about an hour or until set.

                          1. I like tapioca the best. I didn't use enough flour the last time I used flour in a rhubarb crisp filling, and my topping sank into the filling.

                            1. What proportions are in your recipe?

                              I follow a recipe from the old Better Homes & Gardens cookbook, which calls for 4 cups rhubarb in 1-inch chunks (I go by weight, and use something around 1.5 lbs. rhubarb) and then 1/3 cup flour and 1.25 cups sugar. (No egg.) The pie is only very wet if cut while still warm.

                              I wonder, though, if the variety of rhubarb is crucial. I use an older variety which has relatively thin stalks that are as much yellow as red or pink. I bet those behemoth, dark-red stalks that I see in the supermarket havce a higher water content.