UV sterilising wort

[PeteB]

I am using a lauter tun to make 100% rye.

Rye mash is well known to have very long runoff times because of its viscosity.

The lenght of time allows a greater chance of an infection taking hold before the yeast starts.

If I put a UV steriliser in the line where the wort comes out of the tun this should greatly reduce the chances of getting an infection in my fermenter.

Any experiences, comments or theories would be most welcome.

PeteB

[Brian]

Xylanase...you want bacteria within limits....

[Cutty]

PeteB,

My 2cents. I would not use a UV sterilizer for this application. The high intensity UV light is an effective sanitizer because many organic compounds have strong absorptions in the UV spectrum. The absorption of UV light causes some of the bonds in these compounds to stretch and become susceptible to decomposition or reaction. When it comes to bacteria in your water supply this is very useful because it disrupts and decomposes many of the organic molecules the bacteria are composed of, this is the same reason too much UV exposure from the sun, or tanning beds, damages skin and DNA. If you use a UV light on your wort (i.e. organic soup) you would likely decompose some of the chemicals in the wort reducing their concentration, in addition free radicals can be formed from the decompositions, which can then react with other chemicals in the wort creating off flavors. All this said the UV degradation effect, I just described, may be minimal and imperceptible to the final spirit, but I would consider it a potential problem to be aware of. Seems to me a better approach would be to modify the temperature of your runoff by sending it to a heated, or chilled, storage tank (e.g. jacketed fermentor) until the runoff is finished and then adjust to the proper pitching temperature.

Cheers, Ian

[Jason Parker]

If I put a UV steriliser in the line where the wort comes out of the tun this should greatly reduce the chances of getting an infection in my fermenter.

Hi Pete,

Unfortunately, UV light only works for steralizing clear liquids, such as water, as the light must contact each and every bacteria cell in order to do its damage. Good thinking, though.

All the best,

Jason

[PeteB]

Thanks for the suggestions.

Brian, I did try Xylanase once to no avail. In theory it should be the best enzyme for rye, from memory it is arabinoxylans that cause the high viscosity. I have just ordered some more to give it another trial. I think beer brewers boil their wort at the same stage I was thinking of using UV. Maybe a few bacteria are good for Whisky but not beer!

Ian, Your theory certainly has merit. But as you say it may not cause a problem in practice. Hopefully someone has tried it and can say YES or NO.

Jason, I was hoping my wort is clear enough to let the UV travel far enough. A sales rep is coming next week to have a look.

[Charles@AEppelTreow]

Pete, our partner orchard uses a 'CiderSure' unit on sweet cider. It's not wort, but it's sure not water, either.

The unit runs the cider through a dialysis bag material. It's a cylinder with the UV lamps in the middle, and the cider flow as a thin cylinder surrounding them. The optical density is monitored and used to control flow rate to ensure an adequate exposure. I seem to recall seeing info on a similar unit that ran the cider down an inclined plane. Doing the UV exposure as a thin film seems to be important.

The CiderSure does a 5log kill of test organisms. I don't recall what is used as the model microbe. I think it's a LAB of some kind. That compares to thermal pastuerization at 8-9 logs. I think of the UV treatment as 'sanitizing' rather than 'sterilizing'.

But more to the point, I've done fermentation trials with and without it, trials that included samples with no pitched yeast. The CiderSure barely slowed down the wild fermentation. The brix drop lagged 25% behind in the UV treated sample, compared to the control. And both acetified to an unacceptable degree after the primary ferment. None of the pitched yeast samples turned to vinegar.

[PeteB]

Charles, the CiderSure is exactly the type of unit I had in mind, with a thin film.

I was trying to destroy mainly LAB and wild yeasts, but from what you have said I had better put the UV theory in the trash can.

That idea was quickly sorted

Thanks all.

[Denver Distiller]

If you're truly that concerned, the no-cost option is to pitch early, and not wait for the entire run off to have collected in your fermenter. The healthy yeast will outcompete the bacteria.

Pardon me for asking, but why are you lautering this rye mash?

[Brian]

Thanks for the suggestions.

Brian, I did try Xylanase once to no avail. In theory it should be the best enzyme for rye, from memory it is arabinoxylans that cause the high viscosity. I have just ordered some more to give it another trial. I think beer brewers boil their wort at the same stage I was thinking of using UV. Maybe a few bacteria are good for Whisky but not beer!

Ian, Your theory certainly has merit. But as you say it may not cause a problem in practice. Hopefully someone has tried it and can say YES or NO.

Jason, I was hoping my wort is clear enough to let the UV travel far enough. A sales rep is coming next week to have a look.

I can send you some of what I use for you to try....if you have ever used pectinase with fruit you should see a very similar response with your rye. pH and temp error bars are critical and my enzyme would be de-natured at a higher temp. It is an SOP for us and presents a remarkable difference in the mash viscosity, heat exchange in fermenting, better fermentation since the yeast sort of become surrounded by slime and can no longer show their osmotic selves to new sugar waiting to be turned into the elixir of life.

If you can get the viscosity down the mash will chill faster, you can pitch earlier, (see other comments in this thread) and hopefully out compete the LAB with your yeast.

LAB bad for beer, good for whiskey (managed correctly)!!

[PeteB]

Thanks for the responses DenverD and Brian.

I do pitch some of the yeast as soon as there is some wort in the fermenter. It is all pitched by half of runoff. My main concern is too many "bugs" growing in the mash tun. Recently the mash started to spontaneously ferment before it had finished running off and I almost threw the lot out. I kept going and the alcohol yield was the highest to date, and the low wines had similar nose. It takes over 24 hours to runoff hence the chance of infection.

I do wonder some times why I lauter. Before I started my own rye distillery my only experience was with "Scotch" style production, so I just keep doing it that way. The main reason I don't change is because my still is direct fired. Also I think I will eventually find a way to speed up the process enough.

Brian, a small amount of LAB may be good for my rye. I think that the acid they produce reacts with some of the alcohol producing an ester that has a very fruity nose. Sometimes when I walk in while the still is running it smells like fruit cooking in a kitchen If I get too sterile I might lose that note. I am certainly not goung to rush into any changes.

Brian, I would also like to find out more about this enzyme you use. I dont know if you wish to discuss it on the forum so I will send you a PM in case you would rather go that way.

PeteB

[lightcahill]

100% rye is smart, that way you can use more chemicals. I think you should use as many enzymes as possible and keep lautering. It makes a lot of sense to me.

[PeteB]

Lightcahill the Newbie, I think you are trying to be rude about me using "chemicals".

I am using 100% rye because I am a craft distiller and don't want to produce the same product as the Big Boys, and because I love a challenge.

If you had been around this forum a bit longer you might have noticed that I am about as green as one can get with my distillery.

I grow and harvest my own rye, (no herbicides, fungicides or insecticides used) with a tractor powered with waste fryer oil. My still and water heating powered with fryer oil, malt is used green to save energy of kilning, waste products fed to my livestock or used as fertiliser, I capture all my own water (not town water full of chemicals) cooling water is used for heating then recycled. The small amount of electricity I used is from hydro generation.

Most of my mashes have been done with no additives (except hot water produced with biofuel) hence the long runoff times. Lautering works fine, it is just slow and I am concerned the mash might get infected one day. Have tried only a few experimental batches with enzymes (they can hardly be called "chemicals" in the way you imply because they occur naturally in malt, but at a lower concentration) but they have not made runoff any faster.

Also, under your definition of "chemicals" do you include yeast? I doubt it. Yeast is a heap of organic "chemicals" that come in a bag. A lot of whisk(e)y has been made without adding yeast, but usually with unpredictable results.

The reason I started this thread was to try and keep away from "chemicals" by using UV

I CHALLENGE YOU TO USE LESS CHEMICALS THAN THAT.

[123misha]

Do you think UV Light is really effective as a way for disinfection? Really curious since I want to try it and want some opinions from you guys

[Hudson bay distillers]

Love your set up pete it has been the inspiration to many changes in our distillery.  

Tim

[adamOVD]

Cool post from the past. Are you still lautering your rye @PeteB, or have you switched to on grain? If you are still lautering I'm sure you've got it dialed in now.

Breweries often use rice hulls to help speed up sticky run offs. Knowing what I do now about the variety of enzymes, if I went back to brewing I'd probably use those too. Most brewers aren't too familiar with them because they work almost entirely with malt.

[PeteB]

"Cool post from the past" it is, 9 years ago.

I am still lautering the rye, 10 years now, but not in the traditional way, I am using a belt press. I think I posted a video of it working on this forum a couple of years ago but can't find it with a quick search.

I am using enzymes. When I went to larger mashes they were so viscous that it would stall the stirrer motor. We now add a high temperature enzyme to the hot water before adding grain. Completely eliminates balling problems and greatly assists with speeding up cooling before malt addition. But we think this enzyme is causing a much higher viscosity at the end of fermentation. Whatever that viscosity is, it has been causing charring on the base of the direct fired still. I quite like a small amount of charr note but it is sometimes way too much and we get a burnt note. That burnt note tends to dissipate with time in the barrel but we haven't released any yet.

There may be some on this forum who know a lot about starch breakdown and may be able to help.

I think the high temperature enzyme might be shortening the starch chains which reduces the viscosity beautifully, but those shorter chains are not being completely broken down by the next stage enzymes.

We have done just one trial with another enzyme that appears to have fixed the problem and we had no scorch. I have ordered more of the enzyme so lets hope that is what fixed the issue. I will keep you posted.

 

[Jedd Haas]

Pete, 

What enzymes are you using and what temperature are you adding it at? I have tried a number of different high temperature enzymes. My favorite alpha amylase enzyme so far is Amylex 5T, which is (apparently) from a company in Denmark (Danisco) but made in China and it's all part of the DuPont conglomerate. I add it on the way up, temperature-wise, at around 130 or so. It's rated for around 190° F, so I suspect it denatures as I go to 200-210 and hold there. But the mash stays thin; and once I go back below 190, I add a bit more just to be sure of full liquefaction. 

For reference, you may recall this other thread which has some great information about enzyme protocols for rye. 

 

[PeteB]

Hi Jedd, I somehow missed this reply from you. I will look up the names of the enzymes I am using and get back. 

I hope you are keeping safe with the current situation the world finds itself in. Particularly nasty in your country.

[RodneyAdrain]

I comment as a commercial winemaker and only recently am moving into distilling.   Wort like grape juice have several things in common.  Every mixture/liquid/chemical etc has some pH.  It has a total acidity based on multiple different acids in the mix.  Don't mix up Total Acidity and Ph as they are not the same ...  So to me all fermentations start with a sound pH that you have adjusted prior to fermentation.  The pH of different wort mixtures you will have to ask. I know wine only.  If you don't know the pH of the solution your just playing around and giving a guess.  If the pH is correct for the wort then what is the Nitrogen level of the wort? Again if you don't know by a test you will have to rely on some ready formula  to put so much of DAP or other Nitrogen Food source.  I am sure in here someone has that.  Then if both of the above have been corrected then last is a high quality yeast.   In wine making I have simply pitched yeast, created yeast starters using the yeast and some of my grape juice and obviously a yeast cell has a temperature range that it will live in.  The range for many wines is 60- 80F. Greater then 90F dead yeast.  lower then 60F slow starting/or stopped. If the 3 above factors have been met the yeast will grow quickly and the literal Bio mass of the yeast will over take the potential for spoilage.  It is like an army taking over the pot.  The bacteria/mold etc can't compete.  In wine there is an old standard of 5 grams of yeast per gallon. 5 grams is 1 tsp.  I would guess wort has some rule.  If you don't put the correct amount of yeast the bacteria or infective organism could take hold.  5 grams of yeast per gallon is about 4 million yeast cells in each 1 cc of mixture.  This is a magical number. A bio mass of yeast less then 4million/cc can lead to stuck fermentation and yes your infection.  Yes to much information.

[PeteB]

On 10/9/2020 at 11:29 AM, Jedd Haas said:

Pete, 

What enzymes are you using and what temperature are you adding it at? I have tried a number of different high temperature enzymes. My favorite alpha amylase enzyme so far is Amylex 5T,

For a rye mash I start with a high temperature Alpha-amylase (SPEZYME ALPHA) added to strike water at 90+ degC {194F}

Cool to 72 C {160F} and add malt and Glucoamylase  (GA 400)  and Cellulase (OPTIVIN CELLUMASH)

The Glucoamylase was the first enzyme I found that significantly increased yield. When I went......................

On 10/9/2020 at 7:59 AM, PeteB said:

When I went to larger mashes they were so viscous that it would stall the stirrer motor. We now add a high temperature enzyme to the hot water before adding grain. Completely eliminates balling problems and greatly assists with speeding up cooling before malt addition. But we think this enzyme is causing a much higher viscosity at the end of fermentation.

I have now trialed an additional enzyme Cellulase which works wonderfully at getting rid if that final viscosity which only started when we used the SPEZYME ALPHA. Haven't worked out if alcohol yield has increased but the sweet spirit notes have returned and the burnt note completely gone. Great taste is far more important to me than yield of ethanol.

[Silk City Distillers]

@PeteBWhat's your workflow/process like for mashing in Rye at 194f?  Augering/Milling into a grist hydrator?  What's your grind like?  Curious as we've had a hell of a time mashing in Rye hot.

[PeteB]

6 hours ago, Silk City Distillers said:

@PeteBWhat's your workflow/process like for mashing in Rye at 194f?  Augering/Milling into a grist hydrator?  What's your grind like?  Curious as we've had a hell of a time mashing in Rye hot.

We mill all the grain beforehand. We use a roller mill set a lot finer than brewers are using but would be quite course compared with almost a flour that I assume you use. We dump into the hot water as quickly as possible which may seem counter intuitive to some people. If adding slowly some starch becomes gelatinized so the water gets "thicker" and ends up coating the small balls of flour instead of "runny" water being able to get between the flour grains.

I did build a very simple grist hydrator that worked very well. It is an 8 inch stainless tube with a boat style propeller inside. It is about 15 inches long and mounted vertically on a spinning shaft, and is mounted a couple of inches below the water. When it spins it draws water from the surface and pushes out the bottom like a vortex. Pour the grist into the vortex and if quick enough there is only fresh water coming off the top of the mash to hydrate the grist. I have no need to use a grist hydrator since using the high temp enzyme, but with your finer flour a combination of both might work well.