PeteB

Hellyer's Road, a large Tasmanian Distillery / milk processor makes a cream liqueur, they had to do a lot of trials with different techniques to prevent the cream separating out after a period of time, they almost gave up.

I have edited my comment, wrote it in a rush without thinking through. Was sitting on a plane being told to switch to flight mode.

This was discussed on this forum several years ago and if I remember correctly the opinion was the proof in the tank at the end of the hearts. EDIT please ignore "which is the proof that goes into the barrel."

Roller pressure applied by belt tension only, no opposing roller. Too much pressure would push too much solids through filter belt. Most belt presses have belt running between pairs of press rollers and as you say the pressure increases with each set.

I do my cuts by nose and taste only, with a little guidance from volume to know when to start nosing. I don't allow hydrometers to be used to tell us what a spirit will taste like, those things don't have taste buds. I am trying to make products that taste and smell good, hydrometers measure ethanol which I consider a tasteless by-product. I occasionally measure the cut point from heart to feints for interest and it is occasionally low as 90 proof. Great rye flavours come towards the end. I am running a simple alembic pot still, no plates.

As mentioned, a lot more information is required to do a purely mathematical calculation. To simplify it you could slow your water flow rate until you start losing vapour, then speed up a little until the vapour loss just stops. Measure water flow, the water input and output temperatures. It is reasonably simple maths to calculate an approximate maximum water input temperature at your 8 gpm I say "approximate" because heat transfer calculations become very complex. At the lower flow rate there is less turbulence and the heat transfer is less efficient.

https://en.wikipedia.org/wiki/Belt_filter http://www.vfold.com.au/

Video of my Australian made v-belt press which works very well. Cost me about US$7,000 Cake is much drier, liquid has more fine solids than the vibroscreen but my direct fired still can just handle it without burning. V-belt (1).mp4

I have done a lot of experimenting with de-watering over the last 10 years. With a high % of malted barley at a large size grist, a simple lauter screen like most brewers use is the best option. Hammermilled rye or oats (and I assume corn which I have never done) a simple static screen just blocks. Another trial with a bladder press which forces the liquid through a filter screen was useless. The pressure just pressed the solids into a hard cake on the screen and totally blocked it very quickly. The cheapest option I have found is this Vibroscreen. Cost me less than US$3,000 out of China. I am sure the ones made in US and Australia by Kason would be much better made but more $$$ For basic de-watering this worked very well with no clogging issues. I was using it to remove the solids before fermentation but I found the solids were still too wet and I was losing too much sugar. I am now using a simplified belt press. The vibroscreen has less solids in the liquid than the belt press, but the belt press produces drier solids. Copy of vibroscreen-mash.mp4

There is no external cooling required because the coolant is the cold distillers beer that is feeding the still. The one I built has a tube in tube condenser, the cold beer is counter flow to the hot vapour Another advantage is the feed gradually heats up as it moves along the condenser. When properly tuned the feed will be close to boiling as it enters the top of the column. Also the hot stillage leaving the bottom of the column has no alcohol left in it, a well designed continuous will also capture this heat to add to the feed making this type of still very efficient with both energy and water consumption.

I am reasonably confident I have worked out a very simple solution to preventing surging. Throw a small hand full of boiling chips in the pot. These can be made from broken dinner plates or ceramic tiles. I noticed my glass benchtop still was surging, the pot would boil rapidly then stop and suck back through the condenser. I threw in a few chips of a broken coffee cup and got a very smooth boiling rate. Unfortunately my memory had faded in 50 years, I had forgotten that we always used boiling chips in chemistry lab at Uni. Without boiling chips the liquid becomes slightly superheated then boils off all of a sudden, then slows down again.

For every 1 Kg of 36% you add 0.2481 Kg of 95.7% to bring up to 50% Get yourself a copy of Alcodens, you can download a trial version that will give you about 12 test runs https://www.katmarsoftware.com/alcodens-download.htm

If you still have the heads and tails then mix back and re-run. If not then do as you suggested and add some to your next few batches. If you are cutting by nose and taste you should still end up with full flavour. The only way I see you could end up with less flavour is if you needed to add a lot of water to keep your pot charge at below 60 proof

Also found out the Scottish name for a GRANT is an UNDERBACK

I have just returned from visiting all the distilleries on Islay, Scotland. I asked about recirculating at the start (Volauf) and none were doing it which surprised me. They also stir the grain bed between water additions which would let more fines through. I am fairly sure most Australian malt distillers will recirculate to clear up the wort.

Small footprint, smaller heating cost, smaller cooling cost, use as stripping still then very economical.

Once you get into production you might experiment by not doing Vorlauf, small amount of grain particles and yeast in direct fire can improve complexity of spirit

For a small lauter tun I don't think a mechanical rake is necessary, a hand paddle will do just as good a job and way cheaper My Son removed the rake from his 1,000 litre system, it was in the way and achieved very little

Can someone tell me what a "grant" is? A "home-rolled grant" sounds like something to eat for lunch 😁

With Malt whisky i pitch all the yeast into the fermenter as soon as I have a few litres of wort at correct temperature. Some wild "infection" before yeast added can improve the flavour and complexity of whisky. With my Rye or Oat wort I leave it overnight to sour naturally before adding yeast. It really improves the fruity notes. 100% malted grain can be a bit riskier because the kilning of the malt kills off most of the natural bacteria that help protect the grain from nasties.

I bought a non-certified glass hydrometer from Coleparmer. I noticed I was getting unexpected readings. Discovered a small crack in the base and liquid was very slowly leaking into it. It was a manufacturing fault and Coleparmer replaced it. Also I assumed glass thermometers won't change but I have found some red spirit ones become inaccurate. A small section of spirit can break away and move further up the capillary. Sales guy told me they must be stored vertically.

Are you planning to move to Australia? "rules governing spirits production in Australia" It is not just one document. For example there is Food standards, occupational health and safety, flammable liquids, local council, and the ATO Excise department ( TTB equivalent) just to name a few.

The high temperature amylase I use is Spezyme Alpha, liquid Amalyse

I have tried adding grain before high temp enzymes (accidentally) and have "spent the afternoon spear fishing with a mash paddle" The high temperature enzymes (amylase) I use are designed to add to the hot water before the grain, we end up with way less balling, and they are much easier to break up, and the yield is significantly higher. My oats and rye are hammer-milled fine, looks like flour but has a slight coarse feel. I will try a lower strike temperature then raise the temperature to see if there is any improvement. I hope it is not better because it is a bit time consuming with my setup.

I have not done corn but regularly do rye and oats. That "rubbery ring" you mention, if I didn't agitate vigorously for long enough after adding the grain I got that about 4 inches deep on the bottom. Very hard to break up. Recently I discovered high temperature amylase, add it ....before ....adding grain. Strike temperature 190f. drops to 175 after addition Much less agitation required and balling is much less of a problem and my yield has increased dramatically.