RobertS

Calibration is typically either single-point or two-point. For single point, you use a calibrated hydrometer to read the proof and then compare that reading to the one given by the hydrometer to be calibrated. If the hydrometer you're calibrating is over or under, you record that and add/subtract that in the future to get a true reading. This is done at controlled temperatures - usually 60F - and typically aimed at the middle of the hydrometer's range. For two-point, you make readings at either end of the range instead of the middle.

I encountered this with tygon, and in its case the difference was caused by there being multiple formulations. Several sites only listed it as 'tygon' without formulas, and then disagreed on resistances. Pure PTFE is certainly excellent for alcohol - a PTFE rubber is claiming otherwise may have unspecified additives that are not.

@Foreshot, thank you. I had this image of the sleeves getting caught up and misaligned somehow. Adding it to the list.

We've been using the heat gun, too. I'm trying to figure out if and when we would want to upgrade to a more dedicated tool. Is a heat tunnel that much faster or more reliable than an operator who has fumbled through a couple cases with a heat gun? We are using a tube film style of sleeves, which makes me a little leery since all the pictures I've seen with tunnels have the closed top style sleeves.

I'm with Greenfield. No plates, head goes straight to condenser. Botanicals in a basket in the still head. Scrub the pot before/after a gin run and use the still for stripping before doing the next finishing run. Never noticed a problem and never did a special boil just to clean.

We distill on the yeast and any off flavors we may be getting are in the cuts, not the hearts.

I've used sodium bicarbonate without that happening and usually find mintiness at the start rather the end. How much did you use? Were your cuts the same size as usual? I assume these flavors weren't there when stripping or for other runs with the same recipe and ferment stats?

Our unheated storage in Michigan has been aging barrels nicely, but our oldest is 3 years and I haven't seen what aging in the South is like for comparison. I'd never heard the 50 degrees thing before.

I'd say 2521 is what we have, thank you for looking that up.

Don't have part numbers, but we have a couple of small (3 feet of 3 inch pvc shell) membrane filters in sequence. Makes about 10 gallons an hour, so planning is needed. I keep a 10 gallon milk can sealed up with RO water and clean it regularly, mostly for rinsing things. When I need more than that, I'll fill one of my 80 gallon tanks the day before/morning of.

Thank you for the update, HedgeBird. I am adding that fill head to my wishlist as we move.

Can't comment on its stability, which may bring us back to the original problem. On the other hand and off topic, a pH indicator coloring agent could be an interesting toy for mixologists.

Have you poked around with the dairy industry? I found this place but they may only sell to research labs?

Never handled it personally but this was covered in my classes: Generally Regarded As Safe means exactly what it says. The GRAS list maintained by the FDA is basically as a FAQ and fast-track for commonly used ingredients. To make a case that a non-listed ingredient should be considered as GRAS, find evidence and make the information easy to digest and fact check. Note that GRAS is also application-dependent. A plant that has traditionally been used for color may be GRAS as a color agent, but not as a major ingredient. You will need to find historical examples of your ingredient being used in similar contexts and explain why any differences don't matter.

Generally Regarded As Safe means exactly what it says. It does not require official testing, just that traditional lore has okayed it. There is a central GRAS list that acts as a FAQ; if you are using something there you're good to go. If it's not on the list, you need to do what you're doing and make a case that it is GRAS. EDIT: Google poking says try red cabbage?

Good call.

That is very good to know. Would "removed for further aging" or "remnants from bottling returned to bulk storage" be valid fill-in-the-blanks, then?

Adding a gallon of water to a gallon of alcohol is less than two gallons. A gallon of sugar water to a gallon of alcohol is also less, but not by as much. The trouble is that no one has a reliable formula for that difference of how much based on sugar content. Meercat has been working on one.

I thought that production -> storage -> processing was a one way street? Is there actually a way to move backwards without redistilling?

We take the go-ferm insurance policy as well. A cup in a 17bbl batch is nothing vs the risk of getting stuck.

Lost Spirits is running a log and copper still and has pictures online, but I don't think that qualifies as old.

We dip our beer bottles and use a brass stamp on the top. About a 2 out of 5 on the PITA scale? The brass needs to be relatively cool and warms up pretty quickly after a few wax seals, but using a freezer pack as a rest and having a spare deal with that. Upside, when the stamp gets warm and rips away the wax it makes a nice round seal we can stick on our hats. I'd assume that Tanqueray has some fancy extruder that puts exactly the right amount of wax in that divot and puts a perfect press on every time. You could maybe use something like this to make stamps en masse and have your own peel and stick?

Hot TSP overnight and steel wool did it for us, the stubborn ones were still only about fifteen seconds a bottle.

https://www.law.cornell.edu/cfr/text/19/151.91 CFR says pineapple averages 14.3 brix. I found reference to pineapple wine, people usually add sugar but strangely seem to add MORE acid rather than neutralizing. Do you have a lab still and a grace window for a trial ferment?

Our last bottle order was about $2.50 per once we included shipping.