Double distilling with a 25 litre pot still

[heyhaychapman]

I am hoping one of you can help me. I have had a good look through all the forums here and the net in general for days but still can't find the answer I am looking for.

I am using a 25 litre electric pot still and have run about a dozen washes through. Now I want to try double distilling.

When I do a single run I usually collect 4 to 6 litres ranging from 60 thru to 15 ABV. If I have stripped an all fruit wash I might only have 4 litres of 35% ABV.

Can I double distill on just these 4 or 5 litres?
If I need to add water is there formula to calculate how much ?

I have a feints jar and when that gets up to 10 or 20 litres I know I can run that through no problem but can I double distill these smaller amounts as I go?

HHC

[myles]

For all of the above, take what you have collected and dilute it down to 28 to 30% ABV. Let it settle out for a few hours and then recharge the boiler with the middle section. You might notice a thin film on the surface, you don't want that in your boiler, likewise there might be a thin layer at the bottom that you don't want either.

This is "hydro separating" and you will notice that all the big commercial pot distillers load their spirit still at less than 30% for the same reason.

If you don't have enough 30% for a full boiler charge, just make sure that you cover the element with water before you put in your boiler charge. Or store your low wines until you do have enough. It is easier to wait as the transitions between the cuts on a small boiler charge are really fast.

[heyhaychapman]

Miles thanks very much for replying, you jumped in a months back when I started here too. The element is under the base so no problem there.

Can you explain what you mean by "recharge the boiler with the middle section" If you are talking about the middle cuts i have made on the first run I only have 8 x 500 ml bottles so my middle section would only be a couple of litres.

Tell me a little more about Hydro separating.

My fruit washes are around 30 litres a time which usually takes 30-40 kgs of fruit so I am really hoping to double distill straight after the first cut. Collecting 25 litres of 30 % ABV feints would take me at least three washes and nearly 100kgs of fruit. You don't always get what you hope for though now do you.

[myles]

With the concealed element you can run any size wash that you like. On the smaller charges, you just have the problem with the rapid changes between the phases, which just means that you need to collect in smaller samples around the cut points so you don't waste too much product if you make a mistake.

In your situation with the smaller fermentation's there is another alternative to double distilling. Use a thumper. This does the second distillation (probably more like a 1/2 distillation) in the same run.

The normal method for double distilling works with bigger fermentations. Let us say you normally charge with 20 litres in your 25 litre boiler.

You might ferment 60 litres. Divide that into 3 batches and distill each batch fast. This is a strip run. Don't make any cuts other than a foreshots cut. Each batch gives you perhaps 4 litres of mixed up heads/hearts/tails. Combine them to give you 12 litres that you then dilute to 30%.

The idea is that you ferment enough to end up with 20 litres of 30% to go into the still for a spirit run - THAT is when you make the cuts.

The thing about the hydro separating is that the heads/hearts/tails all have slightly different miscibility in water. Above 40% ABV you are screwed as they all mix, but below 30% they PARTIALLY separate out. You can get rid of some of the heads and tails by never putting them into the boiler on your spirit run.

I would say to use a thumper but also re-check your recipe. I typically use 0.6 to 1 kg of fruit per litre and add about 100gm sugar per litre, just to slightly increase the yield. Our summers are short so the sugar levels are low. There is an argument that the small amount of extra sugar also makes the yeast work faster and acually increases the flavour extraction from the fruit.

I will often calculate the fermentation to give me a "run and a half". I will split the fermented wash into 2 portions. I will do a strip run as described above on 1 portion, and then add the low wines collected from that run into the other 1/2 of the fermented wash and go straight into a spirit run.

A lot of the techniques on the pot still are designed to manipulate the charge going into the spirit still. This gives you a final product that needs minimal dilution to get to cask or bottle strength so that you don't also dilute the final flavour.

Sorry for such a long answer.

[heyhaychapman]

Thank you for taking the time to give me a long answer!

I'll try your advice on adding sugar. Do you take the time to invert it ( as i do for All Bran wash ) or just mix it in ?

I have been using Kiwi fruit as they get cheap here in season. It's a bitch to measure the SG as it pulps up like porridge. I guess all fruit washes have that problem and I know I need to strain some off so I can measure. Also it sometimes catches a little on the bottom of the boiler as the solids sit on top of he (concealed) element. I assume any one boiling fruit was has both of these problems. How do you deal with them?

"You can get rid of some of the heads and tails by never putting them into the boiler on your spirit run" How do I do that? Separate them before they go into the barrel ? Are you saying they suspend themselves in layers. Like a Tequila Sunrise cocktail or petrol on water? How do you separate them ?

My big challenge is as you point out is that I am starting out with very little low wines from my first run. I have to admit to feeling slightly depressed by that answer! I feel like I have just stubbed by toe and looked up and seen the size of the mountain. Buying and preparing 30 kgs of fruit and then running the still for 3 or 4 hours I sure didn't feel like I was cutting any corners. What do you think my likely quantity of good second cut will be from those 4 or 5 litres of 30% ABV low wines?

Btw i have been enjoying Ro Palinkas description of making Tuica / slivovitz and have seen the rotary system they have for keeping the wash away from the bottom. Bit beyond my set up though. Might have to start my own village.