Pumpkin experiment

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Pumpkin experiment

Postby hnhupi » Thu Jul 30, 2020 1:45 pm

Leaving this here in the hope something good comes out of this experiment, and others can reuse this recipe. Or be aware of my mistakes :)

A couple of weekends ago I stopped at a roadside veggie stall that had pumpkins for 1 dollar a kilo. Since I missed fruit stone season last summer due to drought, bushfires and life in general I grabbed six of them to give a try to a "fruit" wine, as I remembered reading of people using pumpkins so why not.

Back home I started doing some research and realised that many had tried before, but most had failed :) I was reading both distillers forums and country wines recipes, after some reading I decided to roast the pumpkins rather than using them raw as the recipe that took my attention was calling for processing the roasted flesh and collect the juice to ferment; great, less work to separate the solid from the must later, and I was already making plans for cooking and baking with the leftover flesh.

I proceeded roasting two pumpkins at first, main constraint being the size of my oven. I processed them with a food mill into a cheese cloth but I got maybe half a cup of juice. Obviously my pumpkins were too dry, so I had to change recipe mid flight and use the pulp, in the end I went with the following ratios:

1kg pureed pumpkin (skin and flesh in, but no seeds) / 1L water / 250 g sugar.

24 Jul - Batch #1
3.6 Kg pumpkin
3.6 L water
900g sugar
1/2 tsp citric acid
1 tsp yeast nutrients (prob not needed but why not)

I left the must to cool down overnight and pitched wine yeast the morning after. I forgot to take a note of the yeast type before throwing away the packet :angry-banghead: but pretty sure it was lalvin ec-118, I re-hydrated 1/2 packet and pitched it. Oh the yeast had expired in May but it was still sealed and had always been kept in the fridge so I was pretty confident it would have been fine, considering that I was using plenty for this small batch.
Except that 24 hours later fermentation hadn't started yet. I started getting worried as a fruit cap had formed, it was thick and dry and I was afraid an infection was imminent.

So I started a yeast bomb in a glass jar with sugar, water, a little bit of the must and the rest of the wine yeast. At this point I went into panic mode and started taking rushed decisions :) since the yeast bomb was showing no activity after a few hours, I concluded the expired yeast was really dead so I pitched some mead yeast that I had around, also expired x_x, and waited a bit longer. Then I found a jar at the back of my fridge: the dregs from a mead I made a year or so ago, the liquid had separated nicely and was very clear, maybe a glassful of mead still full of dormant yeasties... down it went into the yeast bomb!
A few hours later the yeast bomb was very active, I was about to dump the whole thing in the fermenter and... I didn't have to: the pumpkin had finally started fermenting, with the wine yeast alone, and was smelling nice. I put away the yeast bomb and punched down the fruit cap.

To clarify, the yeast bomb jar, that is a melting pot of different yeasts, did not go into the fermenter. I am happy about this because I know that whathever the outcome of this experiment, I know what yeast is responsible for the fermentation.

So for the next couple of day I didn't have time to continue working on this project and I've only been keeping an eye and punching down the fruit cap 2-3 times a day.

27 Jul - Batch #2
After work, another two pumpkins went into the oven at 185C for an hour. In the meanwhile I inverted some sugar in a couple liters of water.
Pumpkin was pureed through my food mill, mixed with the water and sugar, added cold water, waited for the whole thing to cool down and dumped it in the fermenter.

8.5 Kg pumpkin
8.5 L water
2125g sugar
1/2 tsp citric acid
1 tsp yeast nutrients (prob not needed but why not)

Day after the fermentation was going very well, while I am still stirring 2-3 times a day, I noticed that I am not getting a solid fruit cap now, I suspect the ongoing fermentation is breaking down the solids. The must is fizzy and tastes like apricot, it's actually pretty yummy!

I haven't been able to take a gravity reading as the whole soup is too thick. At this point I have a 60L fermenter a bit more than half full


30 Jul - Batch #3
Last two pumpkins left to process. I decided to put them in a separate fermenter to keep them both light and manageable, particularly when it will be time to try and separate the solids so I picked a smaller 30L fermenter and proceeded to roast the pumpkins and invert the sugar.
Since I was working on a separate batch I decided to experiment a bit and throw in some leftovers from last summer jam and jelly making: frozen pulp left behind from straining apple, quince and grape jelly. Basically a bunch of cooked fruit without juice, with plenty of skins and seeds, curious to see if these will affect the flavour of the wine.

7.1 Kg pumpkin
7.1 L water
1775g sugar
1/2 tsp citric acid
1 tsp yeast nutrients (defo not needed this time considering I put in grapes skins, but I didn't think about that until it was too late)
~750g apple, quince, and grape cooked leftovers from jam-making.

The must is now sitting at the 14L mark in the second fermenter and cooling down, in a couple of hours I will inoculate it with a couple of litres of must from the active fermenter, that should get it started.

Fingers crossed this will go smootlhy and in a couple of weeks fermentation will be completed. I have colanders and cheesecloth and am planning to get some paint straining bags from bunnings but any suggestion on how to separate the solids are welcome, or any suggestions in general!

PS: don't throw the pumpkin seeds away: put them in a small tray, mix plenty of salt and olive oil and put them in the oven while the pumpkin is cooking. It's a great snack, I've been munching on them the whole week!
hnhupi
 
Posts: 28
Joined: Wed Jun 12, 2019 2:37 pm
Location: Blue Mountains, NSW
equipment: 4in bubbler copper / stainless
50L milk can boiler
2 x 2400W heating elements

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