So, I’m in a bit of a bind when it comes to yeast, I’m having trouble getting healthy packets during the summer.
I do most of my brewing in the summer, since I’ve got night school pretty much the rest of the year. LHBS is 1.5 hours away, and getting up there to get yeast isn’t always feasible. They do ship, but generally I find that they don’t go through yeast that quickly and sometimes I’ll get older yeast. Shipping still has the same issue I get when I buy yeast from NB: by the time the yeast get to me the ice packs have melted and the yeast packets are warm.
What can be done to “de-stress” yeast that have sat at warm temps?
I’m working towards being able to store slants, that’s my future plan for having healthy yeast on hand for the summer. I suppose ordering a bunch of yeast and getting overnight shipping might be an alternative, but if the yeast show up warm I’m in the same boat and I’m out a wad of cash.
are you talking about dry or liquid yeast cultures?
with dry I wouldn’t stress unless you are noticing issues related to poor yeast health. With liquid making an appropriate sized starter with some nutrient included is your best bet for revitalizing the yeast.
Liquid yeast. Dry I don’t worry about, but I don’t normally use it. I do like to keep some on hand for unplanned brews though.
So do warm temps just kill yeast? Or does is stress/do funky things to them? I’d thought about a starter, but I didn’t want to propagate yeast with some sort of problem.
Since the yeast are dormant in their packaging and there are no sugars or oxygen, I’m guessing the heat will kill off a few of them.
Have you tried getting your yeast from Morebeer? With their distribution center in Penn., the transit time to Maryland should be minimal. Keystone Homebrew has pretty quick turnaround time too.
Other than that, doing a starter would be your best bet.
I would like to offer you a word of advice with respect to summer brewing and slants, don’t. The airborne microflora count is extremely high in Maryland during the summer months. I avoid culturing in the summer for that very reason.
With that said, your best bet is dry yeast or serial repitching. Other than a batch made with a vial of WLP022 that I rescued from being sent to yeast heaven, I have been repitching a culture that I started from slant earlier this year. I used dry yeast last year for the two batches that I made during the summer months.
I wouldn’t be too concerned about dry yeast enduring heat. Remember that dried baking yeast sits out on shelves in the grocery store for an indeterminate amount of time and who knows what conditions they experienced before getting on the shelf. Ideally you want that cold-stored, fresh dry yeast but you are fine to use dry yeast with some age or less than ideal temperature experience.
As far as liquid yeast, perhaps plan on buying yeast once and repitching through the summer.
MoreBeer will wrap the yeast in ice for shipment. In talking to the rep at NHC, one recommendation was to order two ice packs per vial of yeast: http://www.morebeer.com/products/ice-liquid-yeast.html Would be nice if they made this option more obvious; need to scroll the page to see it.
Actually, the yeast cells in a White Labs vial or a Wyeast package are not dormant in the truest sense. They are a in state known as quiescence (kind of like a deep sleep). During quiesence, yeast cells undergo changes in order to lengthen the amount of time that their stores last. The temperature at which a culture is stored affects how quickly a yeast culture burns through its stores. That’s why we refrigerate liquid cultures.
With respect to temperature, an attribute that distinguishes ale yeast from lager yeast (S. pastorianus) is the ability to replicate at 37C, which is the human body temperature for those of us who are stuck in Fahrenheit land. Hence, ale strains can physically survive summer heat.
I’ve been ordering more ice packs, even when I order from the LHBS. Between shipping time and being on the end of the UPS/fedex route things are always warm when they get here.
I think this is your answer here. You’re making a starter anyway, I assume, so give it a little extra love, start it small and step it up.
As with many things, I think there’s a greater margin of error than you might expect. Making a robust starter should be enough to account for any handling/shipping issues with the yeast on its way to you.
I’m going to try the starter route. I make starters anyway, so it’s not much more effort do do them with a little more care than normal. I mainly use Wyeast, so I’ll step up packs that don’t want to swell, packs that do swell will just get pitched into a big starter.
I’m not a fan of US-05, which is why I usually use liquid yeast. I’ve just never cared for the beers I’ve made with US-05 as much as the ones made with the liquid “version” of that strain. That being said, I’ve got a batch made with S-04 that’s getting kegged this weekend, we’ll see how that one turns out.
The other issue with using dry yeast is that the beers I prefer to brew aren’t always possible to make with dry yeasts.
Mark, what is your max recommended storage time for reused yeast kept under beer in the fridge?
I too do not care for US-05. Aerobic propagation and fluidized bed drying are not kind to that strain. In my humble opinion, S-04 is the most liquid culture-like dry yeast culture available to home brewers.
What do you brew?
I would say that four months is a good rule of thumb to adopt as a crop management practice. However, most strains will remain viable for up to a year or more under beer if stored cold. Granted, there will not be many viable cells left in the culture. A crop can be directly pitched for about three to four weeks. I have had success direct pitching crops that were older than a month, but it is not something that I recommend. Crops that are older than a month should be fed and proofed before being pitched.
What about the viability of a Wlp tube? I bought some yeast when my local HB store went out of business. It was 036 and 029 and manufacture date is early Feb. I went to run the calculator and it said 0 viability. I know there are enough cells to grow to a pitchable amount. How small and what gravity do you use to bring an old tube to life?
Most of the papers that I have read have stated that viability tends to decline rapidly after 120 days. At 120 days, the viable cell count found in most cultures will be roughly 1/4th of the viable cell count at the time that the yeast was harvested. My own experience with yeast management tends to agree with this information.
If one reads the fine print on a White Labs vial, it states that the culture is basically guaranteed for 4 months from the production date. That number was not pulled out of thin air. It agrees with what I have posted above. Now, is a White Labs vial bad after 120 days? No, it’s just that the cell count is down to around 15 to 25 billion cells, which is an order of magnitude away from the cell count necessary to pitch a 5-gallon batch of wort, and White Labs has always positioned their cultures as “ready to pitch.” I often claim that a yeast culture is kind of like a nuclear weapon in that one only needs to be close for it to work correctly. An order of magnitude is not close, which means that the value of making a starter increases with respect to the distance between the production date and the current date. I currently have a batch fermenting that was pitched with a starter that was inoculated with a vial of WLP022 (Jan/Feb seasonal). The batch started in less than 12 hours.
FWIW, I tend to order yeast from More Beer and always order 2 ice packs. They are always melted and warm from the two day transit. I just figure it kept it cold longer than without. I think I’ll stick to dry yeast during the summer months for now.
Thanks for the information. I’ve learned a lot from you. When making a starter with older yeast, I’ve read the wort gravity should be lower than my normal 1.040. Is this true?