August 26th, 2010

Book About Yeast

Posted by John in Yeast, General

We got a press release sent to us about the latest book from Jamil Zainasheff.  He co-wrote another one and this time it was with Chris White of White Labs.  It’s entitled: Yeast: The Practical Guide to Beer Fermentation.

I have to say that it’s one that I might have to pick up.  I think my beers have gotten a whole lot better since I learned about pitching the right amount of yeast and getting fermentation temperatures under control.

It’s not to say I know everything.  Hopefully the chapters on fermentation don’t just boil down to “get a fridge and a thermostat”…although that’s ultimately what every homebrewer should do eventually.  I guess I am looking for some good in-between steps.

Anyway, I feel I could benefit from learning more about the little critters and this book looks like a great resource.   

August 4th, 2010

WLP566 Belgian Saison II Yeast

Posted by John in Yeast, Brew Log

On the suggestion of reader JW, I bought a vial of the second version of White Labs’ Belgian Saison yeast strain.  It’s a part of their platinum strain line which means it’s only available during certain months of the year.  Thankfully, August was one of the months.

From the description on their site, this one is a faster fermenter than its version 1.0.  It appears that it can take the heat too, so I plan to get my fermentation temperatures up to 85°F.

I need to figure out how I can slowly raise the temperature from 68°F to 85°F, but I will figure that out.  I think there is probably some investigation of room temperature around my house in my future.

I also have a heating pad ready to help out as well.

April 21st, 2010

Should I Use This Yeast?

Posted by Mike in Yeast, Brew Log

So I didn’t get to brew my Brown ale last Friday night. After getting the kids to bed (and waiting to be sure they were in bed), I went to the garage to find some equipment troubles. I had stored my chiller inside my 10 gallon stainless pot. There must have been a little water between the copper chiller and the stainless because I got a little oxidation of the copper. So there was a little green copper on the pot bottom and the chiller. I know that oxidized copper is not something you want getting into the beer. So I needed to look up the proper way to clean oxidized copper. As a result, I didn’t brew.

So now I have a dilemma. I am ready to brew again, but should I use my yeast that I started and chilled. I am looking for ideas. Here is my situation:

I had one WLP001 vial of yeast that was only 14 days past its “best buy” date. I made a starter on a stir plate 2 full days before brewing. I got good growth as estimated by an increase in creamy opaqueness of the start wort post 2 days (looks like most starters I make, so no worries there).

Then I crash cooled it overnight, anticipating I’ll pitch the slurry only the next day into a Brown Ale.

I never got to brew the brown ale - sad to say.

So now I have yeast still in the fridge and settled out. The spent starter wort still above it.

Which route is the best course of action?

  • Pitch the slurry as is after bringing it to room temp.
  • Decant spent wort and add new start wort day of brew session.
  • Ditch the whole thing and start fresh.
  • Something I didn’t think of.
January 14th, 2010

What Happens In A Yeast Starter?

Posted by Mike in Yeast, Equipment

I had to post this wonderful piece of information about yeast and yeast starters.  A great great brewer friend of mine, Wade, over at the BKB forums posted a reply to a discussion we were having about yeast starters and cell #s provided in the yeast packages we all typically buy from WhiteLabs and Wyeast.

Wade, a.k.a. 1n1m3g in cyber-land, is currently working on his PhD in the biological sciences arena and works exclusively with yeast for his research.  He and I have talked in the past about yeast; and he really knows his stuff.  When Wade is not working in the lab or being a great father and family man he can be found bumming around with the Boston Wort Processors.  A homebrew club here in the Boston area. (Please consider checking out their upcoming Homebrew Competition)

So please take a minute to read and digest the post I have copied below.  Its a bit long, but it’s amazingly informative.

From Wade:
“OK, OK, i guess I can try to make some sort of contribution to this discussion here.  I think there is a bit of confusion here about the yeast that come in the liquid from the homebrew stores, either smack packs or vials.  There are two key terms everyone should be aware of and the differences between the two.  One is yeast viability and the other is yeast vitality.  Viability is easy to define as it basically describes the overall number of yeast cells that are alive.  If you were able to count the cells under a microscope and then plate out a small, countable number of cells onto an agar plate the viability of the yeast would be the number of cells that actually form a colony as compared to the number of cells you plated.  Vitality, on the other hand, is a more ambiguous term that describes the overall health of those viable cells.  In brewing terms, it could be described as how fast the cells could divide and as well as how efficient they are at fermenting sugars.  Cells will have high vitality if they have sufficient fermentation precursors stored up.  For example, oxygen is required to build up sufficient cell wall components prior to fermentation because during fermentation (in the absence of oxygen) these cell wall components are not synthesized and are depleted upon every cell division until a lower limit threshold is reached and the cells can no longer divide thereby decreasing fermentation efficiencies.  So, even before you pitch your yeast, you can easily have a population of cells with high viability but low vitality if not properly prepared.  For example, the older a vial or smack pack is the lower the viability is as well as the vitality, but I think that vitality drops off much faster than viability over time. 

So back to the question of starters.  Creating a population of cells with high vitality requires that you give the yeast the proper nutrients that prime them for fermentation.  I think this is where Wyeast smack packs are superior to White labs yeast vials.  When you pop the smack pack you release vital nutrients to the yeast so the somewhat dormant yeast greatly increase their vitality.  There is no way to do this for White labs unless you use a starter to wake them up.  A starter is useful for both because depending on the starter technique you use you can greatly increase the total number of viable cells while at the same time increase the overall vitality of the entire population.  The most important component for the starter is oxygen.  Why force the cells to start fermentation in a starter when you are just going to pitch them into an oxygen rich wort, which inhibits fermentation, only to have that oxygen quickly depleted requiring a switch back to fermentation?  If you use a stir plate to add oxygen continuously to the starter you can greatly increase the overall numbers of cells in a smaller volume of starter wort.  These cells will have built a nice ample store of the cell wall components required for proper attenuation of your beer.  If you prefer the more traditional method of a still starter you will be better off if you give the starter a stir twice a day or so to scrub out the built up CO2 and introduce more O2.

I think a better place to add things like yeast nutrient (i.e. Servomyces) would be at pitching or a day or two into the fermentation.  The yeast nutrients add things like metal ions required for enzyme function as well as free nitrogen required to synthesize these enzymes.  Adding this to the fermenting wort of your beer will give the yeast a boost as they use up the limited nutrients that come from the malt.

I use a stir plate for my starters because I don’t use smack packs or vials, but am instead building up my population step by step from literally a single yeast cell.  I need the extra oxygen to get to the proper number of viable cells with the added benefit of also getting high vitality.  Either way, though, if you are using store bought liquid yeast, make sure the package is as close to the manufactured date as possible and if you have the capability, use a starter of any technique (stir plate of otherwise) to increase cell vitality.

Wow, is that enough of an explanation?  smile  Cheers!”

(Standing) BREW ON!

August 7th, 2009

Choosing Lager Yeast

Posted by Mike in Yeast, Ingredients, General

So I am thinking about my first lager session.  I was going to shoot for a Marzen/Oktoberfest style amber lager.  Who knows maybe ready for October!?!?

But I was wavering between using the White Labs Marzen lager yeast or using the White Labs German Lager yeast.  (WLP820 and WLP830, respectively)

I’d like to pick a lager yeast that I can move forward with on subsequent lager beers.  I have heard and read that its best to pick one lager yeast and get comfortable with how it performs, then use it as your standard lager strain.  As opposed to chasing down a different lager yeast for every different lager you do. (Like we do with Ale yeasts).

Anyhow, I am swayed by the marketing of an Oktoberfest yeast called ‘Oktoberfest’ yeast.  However, I am wondering if I might be better served with using a “utility” lager yeast like WLP830, German Lager that I would definitely try out in the future on beers like Dortmunder and Helles.

Any experience in our readership with WLP820 vs. WLP830?
Or what do you use instead.

BREW ON!

June 7th, 2009

Yeast For American Wheat Ale

Posted by John in Yeast

I am getting prepped for my next brew:  Honey Wheat Ale Recipe

I was reviewing the recipe and I started to think about the yeast strain that I chose.  I think that the clean fermenting California yeast will be fine, but there are a couple of other strains that might be nice.

Wyeast American Wheat 1010 - This strain ferments dry and produces beers that are crisp and low in esters. Ferments in the 58° to 74° range.

White Labs WLP320 - This strain does produce some slight banana and clove flavors.  It is not as clean as the 1010…but it may add some flavors to complement the honey malt.  Ferments in the 65° to 69° range.

I think I am going to stick with the WLP001 but if my local homebrew shop is out of it, I may be in the market for some of these other strains.

April 10th, 2009

Reusing Yeast Safely

Posted by Mike in Yeast

After fermentation is over its pretty tempting to reuse the cake of all that good yeast you have.  I like to reuse US-05 (fermentis) because it really seems to perform extremely well on repitch.  It seems to attenuate a little better, flocculate a little better, and it certainly gets an even cleaner flavor.  I tend to collect some slurry on the same day I plan to repitch into a new batch.  So I don’t store the yeast for any appreciable time.

Many brewers really like the idea of collecting yeast slurry from a batch and saving it for a future brew date.   I don’t do this too often because I think the process of handling the yeast, transferring it from container to container, making a new starter and then repitching just seems risky.  The number of steps increase the number of opportunities to contaminate your yeast with foreign microbes.  I ask myself, is it worth a $30-$40 batch of ingredients to save $6-$8 on a new pitch of yeast?  For me it’s not.

Recently, I have read more and more about brewers collecting, storing and repitching successfully.  Certainly, it can be done (as many brewers do it already).  But I think that for the average non-microbiologist type if you get a little lax once with your handling you’ll probably pick up a minor contamination at some point.  The purpose of this post is not to discourage people from experimenting with yeast management at home.   Rather, I wanted to relate my perceived risk to cost ratio and offer a couple easy steps to try and maintain cleanliness.

Maintaining cleanliness:

  1. Sanitize more containers than you think you need.  If you are going to collect yeast properly you’ll need to have at least two sanitize containers and some sterilized water.  I would over estimate everything by a factor of 2, so maybe for containers and a liter of boiled and cooled water.  This may seem mundane but its too easy to need another container then half-assed sanitize it because of the worry of time on catching a contaminant.
  2. Work in a clean and breeze free area.  Now, don’t think you need to sterilize your entire kitchen to do this.  Just keep your general work area free of dust.  A couple good wipes of the counters with sanitizer would be a good idea.  Keep doors and windows closed to minimize airflow.  Try and do your work when your 4 year old isn’t going to be running by every 5 minutes.  These things stir up dust which can get into your samples.
  3. Create an updraft with an alcohol lamp.  You can even use a candle or something, but if you are working with small containers just working near an open flame will keep the air moving in an upward direction, which in turn keeps things from falling into your samples.  If you want to really get fancy you can do a google search for aseptic techniques and how to “flame” an open container (not always good practice if you use mostly plastic).
  4. If you suspect you have contaminated your yeast, then don’t bother saving it.  You’ll have to taste the beer you just made before even trying to save the yeast.  You’ll need to train your palette to be more in tune with subtle off flavors.  Regardless, it may be impossible tell at such an early stage.
  5. Good yeast collection starts before you even put the first beer in the fermentor.  Most of us do a great job of cleaning and sanitizing the inside of our fermentors, but what about the outside.  There are a lot of weird lips and edges on the opening of the bucket below where the lid attaches.  At least a carboy is a little smoother.  But these areas and the outside of the lid need to be cleaned before a finished beer gets opened.  When you pry open the lid of your fermentor any dust and contaminants on the surface can get kicked up and into you beer…or yeast cake.  So be aware while you are racking the beer out you are sucking air into the fermentor.  If the lip of your fermentor or the air around you get contaminated your likelihood is veyr high that it will also get into the beer and then on the yeast cake.  That alone is something that is very hard to control (a little easier with a conical) and one of the reasons I don’t bother.

I am sure I’ll get a lot of “Oh you are worrying” too much.  Maybe I am paranoid as a guy that does this type of stuff at work regularly and works really hard to minimize contamination.  It’s still a matter of personal choice.  I think its great for people who do it regularly and I encourage anyone interested in that part of the hobby to give it a try.  For me however, I don’t get to brew as often as I like.  So when I do brew, I don’t want to lose a batch to a potentially contaminated yeast source.

BREW ON!

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