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About stevea

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  1. Yeah - mibad - 95.63% by mass, the ABV azeotrope is close to 97% ABV
  2. Hi Silk, thanks. I always find you comments intelligent and on point. On 2) I assume most know, but pH drops with increasing temps, and it's not a trivial amount. An ATC meter reads pH at the sample temp, which is usually unlikely to be the mash tun temp unless you have a high temp process meter, so you have to apply a correction. So pH 5.7 for the HTAA at 85C, will read about 6.2-6.3 if the sample is cooled to 25C, and the meter can't account for it. pH 5.8 @ 50C = pH 6.17 @ 25C pH 5.7 @ 85C = pH 6.45 @ 25C pH 5.3 @ 63C = pH 5.83 @ 25C The delta-pH values for the three rests would be -0.28, -0.62 if measuring at 25C. >>only adjust down for GA, ... Right! My view is that you can likely the 'split the difference' in pH for the gum-rest & liquification rest (BG & HTAA). The HTAA rest does not need to be as complete as the GA rest. The main purpose of he HTAA rest is to prevent the branched amylopectins from trapping all the water, thus stalling the the hydrolytic enzymes (and of course viscosity). Acidifying accurately for GA is critical for good attenuation. https://www.westlab.com/blog/2017/11/15/how-does-temperature-affect-ph >> There is a really popular gelatinization temp chart that's made it's way around the internet. Ignore it, it's garbage. ++. This (below) is the inaccurate chart. It dates to a 2009 aussiehomebrewer forum, and the guy says he pulled it together from another amateur HB forum. The PDF page attached is from "Food Chemistry" 4th Edition by Belitz, W. Grosch, P. Schieberle. Note that Rye is way off in the chart. >> 4) Add your HTAA right after your glucanase rest is complete, it helps keep mash thin. Depending on the specific enzymes used, you may be able to add the HTAA with the GA. In any case I think the arabinoxylanases + BG may improve the rest time and the SG readings late. gelatinization.pdf
  3. FWIW Vendome makes a still a little larger than yours (12" diam) for 3.1gpm (700lph). I don't think you'll get 1000lpm or normal wash feed through an 8" (200mm) rectifier at any reasonable vapor velocity. Reboiler design is a complex issue, particularly if you are processing wash grist-in. Many stills this size and smaller use direct steam injection to avoid fouling. Condensers are just heat exchangers, and they have to be sized to the load. To get 100% reflux from a top plate you need to match the heat of vaporization of the two components (ethanol&water) according to there molar flow rates. 95.63%ABV is the azeotropic limit to water:etoh separation near atmospheric pressure - you can't get to literal 96%ABV that way.
  4. 100% rye is a sort of torture-test. You might try a <70% and see how it goes. There are Dupont viscosity reducing enzymes from Gusmer's available aimed at rye & wheat. I don't have experience but Headstill wrote about them a while back. These reduce the arabinoxylose & hemicellulose 'gums'. The prices aren't bad at all, but the minimum qty is like 25kg. IoR is an indirect measure of sugars (and anything else that differs in rotation from water) , OTOH hydrometry is also indirect and just measures the density. If you want to get hard-core there is a Fehling's test (strips are available as Clinitest) for reducing sugars. You can even measure glucose (not maltose etc) using a diabetic test meter & strips - very easy & cheap. In the US these measure in milligram/deciliter with an accurate range ~50-200 mg/dl - so you'll need to understand dilution. A 100 reading on a diabetic meter is 100mg/dl or almost exactly 0.1 Plato (of glucose only). I'm not suggesting these as a regular procedure, but it's nice to have a couple tools in the drawer when things are unclear.
  5. The smallest one I've ever seen close-up was about 8ft diameter. That was used in a chemical plant. I've been told they are sometimes used in petroleum cracking. A Japanese company makes some tiny ones with a 1 to 3 m^2 transfer surface, but I'll wager the price is terrific.
  6. Roger - your 2.5% grade in a 2" tube would dictate a minimum ~33gpm @ ~1meter/sec to keep it filled.. Yes that is adequate for both turbulent flow but only marginaly improves the turndown ratio. Of course you need to be able to fill and empty the shell unlike ...
  7. Mostly agree. At gelatinization the amylopectics go into solution (assuming you have enough water or some alpha-amylase) reducing the amount of solids by 60-70%. (oddly amylose is insoluble). Also the viscosity increase makes the sedimentation velocity drop, but also reduces the Reynolds number (turbulence). Of course the viscosity drops a lot more at sanctification and fermentation. >>If you are recirculating back to the tun, there is no reason to run a slow flow rate. Faster the flow the better the efficiency, don’t get fooled thinking the smaller delta t is a problem. That's not my only use-case. I need to flow milled wheat&rye from a 'gum' tank (~50C, arabinoxylan & hemicellulose degradation) to a gelatinization temp tank near 90C and I have waste-heat I could use to pre-heat it. So not gelatinized, low flow rate, one-pass. >>And those idiot dairy farmers didn’t bother to consider smaller inner tubes Maybe not such idiots, https://www.dairyfoods.com/articles/92787-selecting-the-best-heat-exchanger-for-dairy-pasteurization I see "dual tube", tubes-in-shell and lpates from dairy HX vendors. >If you are recirculating, optimizing HX efficiency is a whole lot less important, since you can just trade time or adjust flow rate. Unless you are paying for water or to run a chiller. You need velocity in the counterflow HX to improve heat exchange in a turbulent regime, and this additionally keeps the solids moreso in suspension. Some have dimpled or corrugated tubes to improve turbulence. I wish that spiral plate HX were available in a size I need - they have no issues w/ slurries.
  8. This is NOT a recommendation - I have no experience with this company, but ... http://sellerscleansteam.com/
  9. It's possible to clog any slurry pipe. You'll find entire texts devoted to 'slurry flow', as the concept is used in mining & mass-transfer. I never suggested it was a bad design, but it's always important to understand the design limitations. At sufficiently low flow rates you will get sedimentation 'sanding' of the solids.
  10. Hey Paul, that's a fantastically priced tube-in-tube, HX. So how exactly is it operated? The 2" inner tube seems to drop ~3+ft over ~40ft length, so that would cause a 50-60 gpm water flow due to gravity. Because of that I assume you pump mash in at the bottom (to avoid airgaps), and water in at the top (for a counterflow). But aren't there airgaps in the water jacket???
  11. Then I've done the impossible ... again (never in a good way). Tubes will clog/wad-up/plug given a sufficient incline and a low enough flow-rate or else on/off pumping. I expect that Paul (and Richard1's) system has a shallow enough incline and high enough flow rate to avoid that. Back when I was fussing with this problem we were using a peristaltic pump, and tho' they can handle some solids in a slurry, they don't like that big wads of particles on the inlet side. Tube-in-tube, like Paul's, has an advantage in that the pump will apply a lot of pressure to any clog/wad. In Richard1's heat-exchanger with the multiple tubes-in-shell, if one tube clogs, the others limit the pressure available to break-up/move the clog.
  12. Actually the larger diameter may be easier to plug!! You want to keep the mash velocity in the tube(s) well above the sedimentation velocity of the solids, and ideally in turbulent, not laminar flow.. The other thing I recently discovered is that vertical & horizontal tubes are harder to plug than tubes on an incline. Civil Engineers have been dealing with 'slurry flow' for a long time. https://giw.updatesfrom.co/which-pipe-design-should-i-avoid-in-my-slurry-pipeline/ What are you all using for grist-in mash pumps?
  13. Why is that SD ? I'm missing the trick.
  14. Safety issues & testosterone contests aside, you can find plenty of wifi controlled relays, but as they require power, none will be a drop-in replacement. You'll need to understand the current and voltage across the switch, choose a compatible relay. Any idea how that switch is wired ?
  15. Reading this (now dated) tale of woe leads me to a few thoughts. The off-flavor was never identified with enough specificity. "Skunky" suggests sulfur compounds, Tim-O-Tees description sounded more like a classical phenolic flavor, acrolein in quantity would certainly be off-putting but unlikely to be described as either "skunky" or "band-aid", 4-VG & 4-VP are phenolics, and in quantity may suggest "band-aid", but there are other phenolic compounds that would sooner cause such flavors. Then there is the long & circular discussion of infection, which are not well evidenced. A half hour with a microscope & a gas-chromatograph would be definitive wrt to these theories. I am inclined to accept Tim's description of phenolic/band-aid flavor. The chances that bacterial infections are so prevalent as to create this flavor reliably despite acceptable sanitation and pitching rates is difficult to accept. Needs labwork, not guesswork.
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