Infected yeast starter. Help!

[McGuerin]

Recently started two yeast starters in two different growlers for a 10 gal batch of weizenbock. I used 1 lb of wheat DME for the fermentables. I poured that into the growlers which I had sanitized by soaking in bleach water for two hours, rinsed, then I pitched in safbrew s33 yeast. Both are fermenting. The first one is fermenting as expected. It has the color of milky beer. The second one is fermenting vigorously and is not as milky as the first. It is the color of the original wort. Both starter have the exact same composition and both were prepared and stored identically at 2230L 27 SEP 13 or about 20 hours ago. Neither has a bad odor and both are too sugary to taste any off flavors. Thoughts?!

Is one infected, if so which one and how can you tell?

Is one growler of yeast starter enough for 10 gallons of wort projected to be at about 1.080 OG?

No turning back now the water and grains are in the mash tun as we speak.

 

[k_mcarthur]

I would think something is going array, could you post pics? What volume of what gravity wort are in these growlers? You yeast is dry yeast right? If so you don't need to make a starter. Use pitch calculator at mrmalty.com to figure out how many dry packs to use, then rehydrate shortly before pitching.

 

[eastoak]

unless you were really short on cash it would have been easier to buy more dry yeast and pitch that, even dry, than make starters with dry yeast. who knows what's going on with your current starters but you are in a detour that could have been avoided. bleach is a great killer of germs and bugs but is not really the best to use in homebrewing.

 

[McGuerin]

I do not know the OG of the starter but it is probably about 1.06. I actually did use 2 yeast packs wyeast 3056 and the s33. The 3056 must've been old because it did nothing for the 1st six hours so I pitched the s33 just to be safe. My lovely wife keeps a pretty rigid budget on my beer making expenditures which is why I opt for making a starter. Can't show pics because my camera died and is in the shop... I threw away 10 gal of porter last week because I had cross contamination with champagne yeast.... Now I am paranoid. I tasted both starters about 40 min ago and the both tasted the same.... I thought slightly tart but it is still so sugary that it's hard to tell. The wort is on the kettle now so I'm pretty much between a rock and a hard place.

 

[k_mcarthur]

I sense some mishandling of yeast going on, that will make inconsistent and sub par beer every time. My suggestion, sanitize really well and aerate wort in fermentation vessel and seal. Go to LHBS ASAP and get two packs of dry yeast. Rehydrate in warm sterile water and pitch. Your wort will be fine for a few days until you get a clean yeast culture. Stick with dry for a while and practice up on good sanitation with boiling and star san before you move into starters and liquid yeast. I have petri dishes of my four strains and when I need them I take a scraping and step it up to pitch cell count. Never had an infection, knock on wood. I have saved hundreds on yeast, sure the wife would like that after the first investment in a flask, stir plate, petri dishes, and agar.

 

[eastoak]

6 hrs is nothing so your initial pitch of yeast may have been fine, no way to tell now though. making a starter is fine but you don't have to make one with dry yeast, dry yeast is like a starter in a tiny bag. being paranoid won't help your brewing, relax.

 

[Phunhog]

If you think it might be infected try using some chlorine dioxide tabs at a concentration of 20-40 ppm. At that concentration it should only kill bacteria and not your yeast. Some good threads out there

 

[helibrewer]

I'm not sure why you are concerned, is it just because they look different? Side by side fermentations will rarely appear identical.

Try not to mix yeast, especially beer yeast with wine yeast. Yeast strains are cultured with a competitive factor...it determines how well they kill other competing yeast strains and wine yeasts (90+%) have a positive competitive factor meaning they will kill the beer yeast.

When yeasts are mixed, it is generally done in seperate fermentations with the results mixed, or one yeast is allowed to fully complete it's cycle before another strain is added.

 

[pdxal]

You need to know the gravity of the starter, and 1.060 is too high a gravity. For growing healthy yeast you want a starter gravity of 1.030-1.040. If you indeed used 1 pound of wheat DME and used 1 gallon of water to fill 2 regular size half gallon growlers you should have a gravity in the vicinity of 1.037. I hope you boiled your starters to dissolve the DME and sanitize it.
Dry yeast doesn't need a starter, and you are spending more on building the starter (and risking problems like your current one) than just buying 2 packs of dry yeast. S-33 won't give you the weizenbock character 3056 would, so let's hope that the 3056 is still alive and kicking.
I sense a larger issue, and if you had to chuck 10 gallons of porter, and aren't sure about the sanitation of your current starters you need to work on better sanitation practices.

 

[McGuerin]

Crisis averted! Eastoak- you're right I didn't give it enough time. And, as stated by Helibrewer, the fermentation did not appear identical. However, both starters turned out just fine. Potentially the 3056 was dominant in one and S33 the other. Either way, both 5 gal batches are doing just fine. Just to be sure, I sampled some the other day and it was great; No off smells, odors or taste. So, chalk this one up to paranoia/impatients.

I have been brewing for 4 years no and have never had a problem with cross contamination or infection... until the last batch of porter. I am new to kegging and had recently kegged a hard apple cider that I had made w/ champagne yeast. Well, i made the rookie mistake of not sanitizing the out-going hoses which is why I ended up with Porter/wine. I have since started soaking the kegs in chlorine bleach for at least a day and running the bleach through the lines but this has done little to ease residual anxiety.

Re: bleach not being the best as a disinfectant- I disagree. Bleach is widely used in both the medical world and the food industry to kill all manner of beasties. Additionally, the military uses it during decontamination operations because it is extremely effective and cheap. Not to say that I don't use star-san. In fact, that is what I'd used on the champagne-yeast-contaminated-kegs. As long as it is mixed in correct proportions (at least 200ppm) and has adequate contact time, unscented household bleach is a cheap and effective sanitizing agent.

I know it can be hard to judge tone via blog but here is a non-snarky question. Why wouldn't I make a yeast starter rather than double pitching? Did not the Godfather of Brewing (Papazian) recommend it? I make a starter every brew (except for the last Porter/Champagne) in order to ensure that my yeast is the dominant culture present in my brew. 100 billion cells supposedly exist in a packet of 3056 (barring degradation of viability over time). 100 billion cells pitched into a 2 liter starter will only grow to a bit over 200 billion cells (growth rate of 2.05), while the same 100 billion cells in a 4 liter (.5 gallon/ 1 growler) starter will grow to about 400 billion cells (i know growth is exponential to a degree). More than enough for a 5 gal batch at 1.075. For example, 5 gallons of ale at 1.048 gravity needs about 177 billion yeast cells. So, a 100 billion cell packet pitched into a starter of just over a liter would be sufficient for that beer. Add another packet of dry yeast on top of that and you have way more than enough. I always do growler sized yeast starters b/c, all things equal, it is enough yeast cells for a 1.085 OG brew. I sincerely thought this is a "best practice". If for nothing else because it affords me the opportunity to panic when viewing the starters the day before the brew. Other than exposing the yeast/starter to contaminantswhy wouldnt i use a starter rather than double pitching? Sure I have to buy an extra pount of DME.... but it gets added back to the beer anyway so I'm not really out anything.

Thoughts?

 

[kombat]

You don't do starters with dry yeast, because the dry yeast has been carefully packaged with the necessary sterols and reserves, ready to go directly to work on your main beer. When you pitch it into a starter, there is very little growth (because the population starts out so high already), and they expend their reserves fermenting wort you're just going to dump down the drain. By the time you pitch them into your main wort, they're already tired and spent, and haven't really grown that much at all anyway.

If you want to use dry yeast, just rehydrate it and pitch it directly into your wort. Skip the starter.

 

[boydster]

Or make a 2L-3L starter so you can actually grow an appreciable number of cells. Fermentis says their packets come with 150 billion cells, although some people have done cell counts and come up with upwards of 220 billion. A 1L starter at that kind of innoculation rate will only grow the population by around 15-25 billion cells. A 3L starter should get you another 120-180 billion cells if done properly.

 

[McGuerin]

I agree. Which is why I used a 4l (.5gal) starter for each 5 gallon batch. I also understand not wanting to tire the yeast out but is that an issue with a starter? If the yeast is healthy, won't It divide and give you extra healthy yeast plus tired yeast?

 

[McGuerin]

Or do you really need only 1 pack of dry yeast per 5 gallon batch? Why then is there all this pitch calculator hocus pocus?

 

[k_mcarthur]

I think we are going array in this thread. Dry yeast used in a starter is a waste of DME and affects cells negatively. The one up side to dry yeast is ease of use, why complicate things? A 4L starter is only needed for tall lagers, pitching that much into an ale is over pitching and affects beer flavors and yeast health negatively. The most important thing in making beer is what you like and being able to repeat it, so if you do these things and it works for you then go for it. But for the beginners, these practices are not ideal.

 

[boydster]

I agree. Which is why I used a 4l (.5gal) starter for each 5 gallon batch. I also understand not wanting to tire the yeast out but is that an issue with a starter? If the yeast is healthy, won't It divide and give you extra healthy yeast plus tired yeast?

Waaay too much yeast for 5 gallons. One packet is enough for most ales. You want the yeast to do some reproducing after you pitch.

If you make a 4L starter, you should be planning on pitching only enough cells to get the job done (usually in the neighborhood of 200 billion or so) and saving the rest for future use in the most appropriate way. Or just don't make a starter with dry yeast. My point was simply that you can make a starter with dry yeast, and if done properly you can grow a healthy yeast colony, but in truth you really don't need to with dry yeast because of the already-high cell count as others have stated.

 

[McGuerin]

Please school me (again honest, non snarky), on the "why". What is too much yeast. What are the negative effects? Specifically. Because now I have 2 differences of opinion in this blog; one telling me I'm not pitching enough and one telling me I'm pitching too much. Which is it?

 

[eastoak]

this chart should clear up what over pitching or under pitching is.

 

[eastoak]

http://www.calferm.org/edu/yeast/YEASTP.htm

Lallemand labs, (makers of Nottingham, London, Windsor etc.) suggest a pitching rate of 50 grams per hectoliter which would be 10 g of dry yeast per 5 gal of beer.

 

[boydster]

Pitching a 4L starter of yeast into a 5 gallon batch is too much unless you are making a beer with an OG in the 1.100 range. Overpitching results in an unhealthy yeast colony. You run the risk of low ester production, autolysis flavors, and poor head retention.

Just re-reading that you did a 10-gallon batch at 1.080 though, and I have to say that a 4L starter for a full 10 gallons I don't think is a terrible idea (I think a second packet would be better, still, more below)... so I apologize for the lapse in my memory. The yeast is prepared with a stockpile of nutrients so that if you pitch it into 5 gallons after rehydrating, it is prepared to go to work on your beer. If you are making a starter in a nutrient-rich solution (like wort) and properly aerating, you are providing all of the nutrition that the yeast need to grow a healthy colony. As long as your process is sound (good cleaning, sanitation, aeration, etc) then you should be fine to build a starter with dry yeast for a 10 gallon batch.

That said... an extra packet of yeast costs how much? How much is your time worth, plus the cost of the additional supplies (DME, yeast nutrient, etc) to grow a bigger colony? I think the extra packet is the way to go.

 

[kombat]

I agree. Which is why I used a 4l (.5gal) starter for each 5 gallon batch.

4L is more than a whole gallon, not 0.5 gallons.

 

[McGuerin]

Kombat. Thank you. You are correct, sir. Slip of the tongue. I made 2x 2liter growlers or 4 total liters of starter.

I will definitely try to find out more about the science behind the "too much yeast" scenario.

 

[kombat]

No problem. As a Canadian (we use metric), I'm keenly attuned to conversion errors.

As for overpitching risks, I'm under the impression that underpitching is vastly more detrimental than overpitching. I have several jars of washed yeast in my fridge, and without the proper lab equipment, I can't be certain of the cell density and viability of the yeast. I have no reservations just decanting the wort, swirling up the yeast, and pitching the whole slurry (100 - 200 mL) into a 5 gallon batch.

I suppose I do adhere to a rough ratio. Specifically, when I brew a batch of medium-to-low gravity beer where nothing was added post-fermentation (i.e., dry hops, fruit, oak chips, whatever), and the trub is basically entirely yeast, I'll capture the yeast cake in 3 Mason jars. I'll then use each jar to innoculate another 5 gallon batch. So in that respect, I'm basically pitching a new batch on 1/3 of the yeast cake of a prior batch. I'm confident that's way more than the recommended minimum pitching rate, but in my experience, I haven't had any ill effects of overpitching to that degree. In reality, it's actually only (as I said) 100-200 mL of concentrated yeast slurry, and it may have been in my fridge for a few weeks, so its viability is somewhat less than 100%. I don't think 200mL of yeast slurry is enough to adversely affect the flavour of the resulting beer.

 

[McGuerin]

I'm with you, Kombat. From what I've read under pitching is more detrimental than over pitching. Unless, of course, someone wants to under pitch in order to cultivate esters etc. Additionally, I don't see any harm in over pitching as opposed to pitching the exact amount needed as long as its within reason.

I used to save some of my washed yeast also but stopped doing so because my cultures would sit in the fridge longer than I was comfortable due to the length of time between brews.