r/AskCulinary • u/Time-Swordfish3228 • 3d ago
Trying to make a pineapple gel, Pastry Chefs pls help
I'm currently trying to make a mostly clear pineapple gel for the base of a tartelette that i'm working on. I made a version of the gel using 250g pureed pineapple (strained, but not removing the pulp entirely), 50 ml lemon juice, 60ml of simple syrup and 2.5 grams of agar agar. The end result had a nice fresh pineapple flavor, slightly too sweet for what I'm going for but the main issue was that there was leakage in the gel which i'm assuming is coming from the lemon and additionally the pulp made it sort of slushy instead of a nice clear homogenous gel. What can I do in my next version to get it closer to what i'm aiming for. Ty in advance
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u/texnessa Pépin's Padawan 2d ago edited 2d ago
It would be useful to know a little more about what you are shooting for when it comes to final consistency/texture and your actual methodology. More detail on what you did in the first place would help to get more accurate feedback.
There are a handful of approaches for working with pineapple for a fluid gel. The easiest base product is to use high quality bottled pineapple juice rather than fresh due to the bromelain issue or use a high quality frozen puree [like Boiron] and heat it prior to adding the setting colloid.
There's a handful of hydrocolloids which work with pineapple- agar is one but you may need to add xanthan to avoid syneresis and agar rations are more like 0.2% to set, but 0.5% gives firm jelly, iota carrageenan at a 0.12+% concentration, low-acyl gellan which is what the Fallow guys use. at 1.5%, and Ultratex at 1% to 5%, which produces a pretty clear, non-cloudy end product that does not require heating.
Additionally, are you using a drug dealer's scale for the hydrocolloids? These finely milled products are used at very small quantities that require more precision than a gram scale provides.
The approach I use when making gels is to use a ratio that sets to a firm solid. Once fully cooled, then stick it in the Vitaprep to blend to a smooth consistency and pass thru a chinois. Though when using Ultratex, I adjust texture by adding more Ultratex or juice as needed because it can just be done on the fly in a food processor. You don't want heat from high shearing for that one.
Edit: I also recommend grabbing a copy of Texture by Khymos which is a free PDF that goes into the food science of all of the usual hydrocolloids and other textural suspects including inhibitors, effects of salinity, tannins, and alcohol, pH ranges, typical concentrations, etc. Handy little document.
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u/ThiverMeSimbers 2d ago
This is the way
I've had good luck with low-actl gellan at 1% and xanthan at .5%.
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u/mrcatboy 3d ago
Did you cook the pineapple? Pineapple contains bromelain, an enzyme that breaks down proteins. If you used raw pineapple juice the bromelain is likely still active and digesting the protein complexes that most gelling agents are made from.
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u/ConstantSperm 3d ago
Ohhh that's a good catch. Bromelain is a sneaky little enzyme, totally wrecks agar and gelatin if you don't cook the fruit first. I'd bring the puree to a simmer for a few minutes before adding the agar and see if that fixes the weeping and texture.
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u/Time-Swordfish3228 3d ago
Ah I see, no I didnt cook the pineapple, just used it fresh. would you recommend pureeing and then cooking in a pot or roasting the pineapple in the oven and then pureeing.
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u/SunnyInDenmark 3d ago
Canned pineapple has the enzyme deactivated. It is safe to use with gelatin or agar agar.
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u/mrcatboy 3d ago
Puree and cook it to 70* celsius (about 160 Fahrenheit) for about 30 minutes. Pretty standard lab procedure to denature and inactivate proteins. Bringing it to a simmer (i.e. the boiling point) while stirring for 5 minutes should also do the trick though.
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u/Aromatic_Sandwich477 3d ago
you're losing the clear set because agar needs a hard rolling boil for a full minute or two to hydrate before it'll gel properly and pineapple's acidity can drop the pH enough to weaken that set.
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u/AbeFromanLuvsSausage 2d ago
If you boil agar in a very acidic environment, it breaks down before hydrating. For lemon gels etc. I usually hydrate the agar in water or simple syrup and then add the acidic liquids once it has partially cooled down, before it starts to gel.
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u/krakaturia 2d ago
that's less than 1% agar agar per water weight roughly, excluding all the sugar and fiber.
you want at least 1.1%. up the agar to 3gm.
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u/bosmanez 1d ago
Agar sets and releases liquid (syneresis) more easily when the mix is acidic, so the lemon is a likely cause of the weeping. Two things I'd try: 1) strain the puree through a fine cloth or coffee filter (or let it drip overnight) so you get clear juice instead of pulp, which fixes the slushy look; 2) drop the lemon and cut the syrup, then bring the agar to a full boil for a minute or two (it must boil to hydrate fully), cool, and blend the set gel smooth if you want a spreadable base. Pineapple's own acidity probably covers the tartness. If it still weeps, a bit more agar is the usual next step. Not a pastry chef, just what I've read on agar behaviour.
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u/Icy_March_3797 1d ago
I think the weeping is acid and pulp breaking the agar network so I’d strain the juice clear, cut the lemon, and boil the agar a full minute.
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u/m4gpi 3d ago
Agar is not a protein, it's a carbohydrate, so while the guess that bromelain is the problem is a good one, I don't think that's it. Bromelain has no effect on carbohydrates.
However, low pH affects whether agar will gel, so I suspect it's the acidity of the pineapple. You can neutralize the acidity by addition of baking soda, but it might make it taste a little salty. If you have pH papers (they are cheap) you want to get it to a pH of 7. Good luck!