Breeding Rum Yeast (Danstill EDV 493)

[kiwistiller]

A very generous distiller has sent me a sample of EDV 493, a (supposedly) great commercial rum yeast, isolated in Antilles from sugar cane molasses.

from the wiki:

this strain is used for the batch production of beverages from vegetal substrates (rum, aguardiente, tequila, pisco). DANSTIL 493 EDV provides organoleptic smoothness to beverages while respecting the substrate's sensory qualities. It also supports the synthesis of ethyl esters of short chains fatty acids, the reduction of amylic and isoamylic alcohol concentrations and the reduction of aldehydes.

So, I figure I'm going to breed up this sample with my stir plate, treat test tubes of the yeast with glycerin, and store in the freezer so there is a good stock of Generation 1 cells to send to people or use myself down the line.

I'd love any and all thoughts on:

• sterilisation: if this was for beer, everything would be pressure steamed to eliminate other bacteria / yeasts. In rum though, bacteria is key, so should I skip this?
• feed stock: molasses? sugar? Dap? If molasses should I clarify it and or sterilise it? what sg/ potential? I'm thinking 6%.
• Breeding: I have a stir plate, figure I should use it... should I try to maintain highish temps that the yeast would like in a normal ferment? (30C sort of thing). Just leave the stirrer going the whole time? Keep it under airlock in the flask?
• Any locals want some rum yeast, sing out now and get me a vessel, because I've only got 11 test tubes spare and I'll be wanting a few for long term storage.
• spent beer: I figure I'll just tip it into the dunder pit.... the creatures in there would probably love some trace sugars / live yeast, right? Right?

[Popcorn Fan]

My god you are the man

Sounds like you did well getting that yeast

[Austin Nichols]

Hey Kiwi,

Sounds like your onto a good thing there, I'm not sure how I'd go about it.

I've got about 8 generations of the Hook rum recipe going, added dunder to 7 of these ferments and they seem to be real happy so far.

I thought I read somewhere that bread/bakers yeast was from a strain of yeast used for making rum, so now I'm wondering if the yeast I have might have converted to the type of wash it's in, or will they finally give up eventually, they would make some really yummy bread & scones if nothing else......

This rum thing seems to be something that a lifetime couldnt master, but very satisfying anyway.

Cheers.

[Barney Fife]

Fun! I believe you want to sterilize the test tubes, as you don't want a random strain of yeast to get in there, and definitely no bacteria. As for pouring spent beer into the dunder pit, I'll guess that's a bad idea, as this is where we want bacteria, not yeast, and adding yeast and alcohol to the dunder pit will make it into a weak wash. For feed stock, feed it the same molasses you will use to make your rum; that way, it will be accustomed to your molasses' nutrients.

I don't think it's necessary to do this in a flask; I'd make a small, say a one(1) gallon rum wash at low gravity(shooting for well under 5% ABV), and let it work until done, then bottle it in small, sterile bottles and/or jars, and I would make sure to get all the trubs and especially the yeast cake. Leave a wee bit of it behind in the fermenter, and start a second wash right away, then keep this one going forever, while you can store and share the bottle/canned ones.

Way cool stuff, any which way you approach it! Keep us posted as to how you go about it(wait for more ideas, as I certainly don't have the final word on this subject), and for sure, ask the fella who gave you the yeast how he would do it, also. He's likely the best authority on the subject.

[rubber duck]

I would do it just like you wash yeast from a beer fermentor. Make up a small sterile molasses wort,( 3-5 gallons) and wash the yeast from the cake. Then take one of your jars of washed yeast, decant the liquid, and pore a little yeast into a sterilized vial of glycerin.

Make sure everything is super sterile, use a pressure cooker or an autoclave if you have one.

One thing to remember is that most freezers cycle so as not to build up ice. This is a problem for yeast storage. Put your yeast bank into a small ice chest and pack it with cold packs, then place it in the freezer. This will keep the temp of the yeast vials stable. You should be able to store it in this manner for 2 years or so before you need to start a new bank.

[CaymanRumBaron]

Any updates on this Kiwi? Any cultures, washs, runs etc.

I trying to buy some myself (dont care about the price much) from White Labs as distilling is legal round here and would like to here about some results.

Peace from the East and God bless your Yeast. (had to)

[kiwistiller]

No updates yet, I'm waiting for a mate to return my BoP. What I'll do is boil and clarify some molasses + water overnight, then rack most to a sterile 30L fermenter under airlock and possibly use a campden tab, rack some to a pressure cookered conical flask, put that on my stir plate, make a starter with my sample, then pitch that into the fermenter. Then I can just sample from the yeast cake, store, and keep using it. Shit, I need to get onto that. My dunder is smelling great. I guess I'll be left with 5 gallons of first gen wash, so I'll probably turn that to refluxed white rum, then the next generation will have some feints and dunder to start with for something with a bit more body.

[kiwistiller]

This yeast rocks.

Shoulda used a blow off tube. It's sitting pretty at the moment in a 28C fermenting fridge, Details to follow...

[kiwistiller]

Ok... So first thing to do was make up a batch of rum wash, get it clarified and as sterile as possible. Used about 3.5l of blackstrap and 1.5kg of sugar for a clarified and cooled SG of 1.06 - clarification drops about .01 or even more off my molasses.

Boiling the wash to sterilise as much as possible.

And a nutirent boil bomb of course, minus the yeast. Dap, Epsom salts, citric acid (no dunder in this wash), extra B-vitimans to cover the ommision of boiled yeast.

The two boils were then added together.

I took my sample for making a starter, pitched a campden tab to finish the job while it was clarifying overnight (the pot seals well). The clarification rest lets all the solids and crap that came in the molasses settle out, allowing me to rack off the top.

[kiwistiller]

Right, so I've got my as-sterile-as-I-can-get wash. While the campden tab is doing it's business, I'll get my starter going. I made a stir plate, and wanted to try it out. I think my magnets are out of balance, but it works.

My stir plate - computer fan, fins ripped off, hard drive magnet attached to motor (with a spacer), attached to a variable voltage adapter. In the finest traditions of my handiwork, everything is stuck together with stickytape.

All set up, waiting to stir :) The flask was pressure cooked (poor man's autoclave) before actual use for those interested in the gory details.

My sample of EDV493, sent to me by an awesome forum member

I first let my yeast rehyrdrate in sterilised water, which would then help lower the gravity of my starter for good yeast growth. Forgot to take a pic of that, sorry, but I'm sure you all understand anyway. After letting it sit in the water for 2 hours, I added the wort (at the same temp, 26C, I love having a temp controlled fridge!)

stir stir stir away.. with the first wort addition.

The wort was added in stages so as to keep gravity low, every six hours.

With the starter going good, it's time to rack our clarified molasses to a sterilised fermenter, and let it wait off the campden effects....

[kiwistiller]

Washed the fermenter with PBW, then sterilised the fermenter with starsan (don't fear the foam):

foamy :)

Then racked the wash off the sediment with a racking cane (this is probably the least sterile part of the operation).
The fermenter goes into the temp contolled fridge to get to the same temps as the starter.

Later:
The starter is finished, bred up a good amount of yeast considering the low gravity of the starter.

yeasty...

After the fermenter and starter were both ready, I pitched the whole starter, which brings us back to this:

violent ferment...

The ferment smells very different to other rum ferments I've done. Almost chocolately when it was dry in the starter. I'm very curious to see how the flavours carry over when the ferment is finished, and excited to do a ferment with dunder later on.

Cheers.

[lordyd]

I got brew shop to import some 493 into Aus for me a few weeks back but haven't tried it yet, going to be watching Kiwi's efforts to see how he rates it vs bakers/brewers yeast. If any Aussie's with a fair bit of rum xp want a bit to try I'm happy to post a small bit , just pm me.

[kiwistiller]

well I can tell you it's a bloody fast fermenter... We'll have to wait and see for the distillate though.

[CaymanRumBaron]

Good on ya mate

I am on the edge of my keyboard awaiting the results. Theres only so much one can do with bakers yeast.

I fermenting a mash with a mixture of a wild culture (wild yeasts and hopefully some bacteria) and bread yeast right now. Looking inside the fermenter, I did notice that along with the general fizzing of the microsized CO2 bubbles, some much larger bubbles were regularly coming to the surface. I did not notice this in any of the ferments before. I also noticed a different smell from the wash, much more sweeter as it nears the end instead of the usual sour smell.

Keep on the path Dr. Kiwi

[kiwistiller]

The airlock is down to a bubble every 15 secs about 60 hours post pitching. My heaters are having to keep it warm now, it was producing plenty of heat itself (too much in fact) in the first day.

[kiwistiller]

So, the ferment is done, finished around 1.015, dry as the proverbial statue's tits, and all in under three days

That is the fastest ferment I have ever had, easy. even my explosive DWWG ferments have taken 4 days or a bit more.

I've got no airlock activity, but I'll leave it for a day more just to help the yeast start to floculate, then I'll turn down the heat and crank up the refidgeration, and cold crash to get most of the yeast out. Then comes the yeast farming. I should get some more glycerin, I don't think I've got enough on hand.

[CaymanRumBaron]

Kiwi,

Is the glycerin a food source or just a medium to keep the yeast alive in? I am thinking it is the same glycerin you can get a the pharmacy, the thick clear stuff.

Also how much new starters batchs do you think you will reap from this first generation?

[kiwistiller]

It lowers the freezing point, preventing the yeast cells from bursting due to crystalisation. You only need a tiny amount to breed a starter with, so I'm planning on taking 10 samples and having plenty leftover to just pitch straight into my next batch.

[CaymanRumBaron]

Thanks Kiwi,

I have seen many folks on here talk about doing that and i always wondered how you could store live yeast cells in a freezer and not have them burst and die. Answer > Glycerin lowers the freezing point of the medium. Good to know.

[Liquid_Luv]

Kiwi, you have my undivided attention on this one... I am hoping you will keep some continuous updates on the quality of spirits resulting from your first generation run through several generations.

I am getting ready to knock up several 54 liter (12 IMP Gals) Rum washes, each being experimental in nature... I will either continue on LWTCS's "Rum Talk", or get a new thread going once all is well on it's way. I am always in quest of improvement when it comes to rum... and I believe the yeasts play a major role. Although I have been blessed with many successful runs, and have tried many recipes, and successful Dunder variations... I have been limited to Bakers and EC1118 as far as yeast strains... I have even used both together with excellent results... seems the Bakers got things off to a fast start, then the EC1118 kicked in taking the ferment to dry at the higher abv. I am curious to see the effect on flavor profile using different yeasts... especially this one.

Kiwi, as you seem to have quite an experience with yeast, have you ever cross bread any... or is it even possible to create new strains by mixing for a few generations in the same type of wash?

Great Post... Thanks!

[kiwistiller]

I am hoping you will keep some continuous updates on the quality of spirits resulting from your first generation run through several generations.

Of course. If the smell of the wash is anything to go buy, the first generation at least will taste quite different to my previous rums. I won't be able to say anything definitive until I've got a few generations going, and there is a nice dunder + feints cycle happening.

Kiwi, as you seem to have quite an experience with yeast, have you ever cross bread any... or is it even possible to create new strains by mixing for a few generations in the same type of wash?

Great Post... Thanks!

I don't have that much experience with it really. Rubber duck would be a better guy to talk to, or any of the really experienced beer makers. That being said, yes it is possible to create new strains, but it's very had to do accurately without a lab. Some yeasts compete as well and kill each other off. whole other science there.

[CaymanRumBaron]

Although I am not a expert by any means, I think most common strains of yeast that we use are asexual and reproduce from budding, meaning that a new yeast cell buds from the mother cell and eventually becomes a separate cell. So yeast do not breed or mate persay, but just reproduce.

That said, each yeast strain will have its own genetic stabilty and some strains much more stable than others. Even so, each yeast cell is genetically different from each other, however small those differences are. This allows them to adapt to new environmental conditions. Over thousands, probably millions of generations, a yeast strain can become more tolerant to certain conditions or develop certain desirable traits, like high alcohol tolerance levels or high ester production, because only those that survive (or those we select to reproduce) will carry that gene. Ofcourse, knowing how to "steer" the yeast to where you want them is not so simple.

Like Kiwi said, a lab would be best as they would would have hundreds of small fermentations happening and only allowing the yeast which produce desirable traits to continue to reproduce. The lab would also be able to accurately measure ester production, sulphur production, exact ABV levels, etc and maintain a higher level of consistency than we could. Still, each time we do a ferment, the yeast that like those condtions the best will reproduce the most so that in a few washes, you may have a set of yeast that will thrive more easily in that wash than the first set of yeast given the conditions stay the same. At what rate they adapt, I dont know.

[Dnderhead]

I believe you got it Cayman.I used to use wild yeast and it gained efficiency over generations.survival of the fittest.
with rum,for the same reasons many use the "foam" off the top of fermenter as this contains a lot of yeast.
and also retains the same flavors

[CaymanRumBaron]

Thanks Dnder for a actual case.

So Kiwi, when you gonna still that bad boy?

[kiwistiller]

I'll leave it in the cold for another day yet I reckon, and then I'll rack off to the boiler and harvest the yeast. Haven't decided if I'm making slants or washing and storing on glycerin in the freezer yet.

[kiwistiller]

Mr Rum Baron has helpfully provided this brochure on EDV493. Has some data that compares directly to bakers yeast and wine yeast (1118 I'd guess), so worth the read. They also note the great flocculating characteristics I observed.

[kiwistiller]

I'm sampling the hearts of this first run at the momement. long reflux in my half VM column, then run off at a RR of around 0.7:1. First impressions are: much fruiter than I was expecting, but a very clean taste without much in the way of fusels, almost a crisp taste. Not much butteriness, but there was lots in the heads. I'll need to get a couple of generations done now with feints and dunder to get a fair appraisal.

[CaymanRumBaron]

Kiwi, So I pitched the yeast last night. Think I underpitched though. The directions state 50-100 grams per 100 liters (Hectoliter). I took the middle value of 75 grams, divided that by 100, which is .75 grams per liter, times 25 liters for my wash, works out to 18.75 grams.

I thought i read somewhere that a teaspoon of yeast is 6 grams (it is actually only 3 grams) so I pitched 3 teaspoons (should have been closer to 6) in some water as per the directions, hydrated the yeast for a few minutes and then pitched into the fermenter which had a SG of 1.055. Evidently the water that you hydrate the yeast in has to be quite warm at 104F (40C).

This morning I was getting a few bubbles every 10 secounds or so. Hopefully as the day warms up, it will get going as it seems to like warmer ferments. Man I would kill for a stir plate and flask though.

[kiwistiller]

Well, you can just chuck in some more yeast, can't you?

Stir plates are dead easy to make, if you can find a broken down old PC all the bits you need are inside it.

[CaymanRumBaron]

Thats what I did, i pitched 2 more tablespoons of yeast in there and stirred them in. I also wrapped the fermenter in a old bed blanket to try to bring up the temps as that was half the problem as well. The temp rose about 4 degrees and is holding at 86F, up from 82F.

It has been 5 days and with a SG of 1.055, its down to 1.010 and bubbling every 20 seconds or so. The next ferment will probably be much faster as i will be reusing the yeast bed which should have a very good amount of viable yeast.