FAQ for Homebrewers
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Homebrewers often ask us the following questions. We hope our answers are helpful to you. Use your browser's search function to find keywords that are associated with your question. If you have a different question, please email us.

If you are looking for FAQs regarding White Labs nutrients, including White Labs WLN1000 and Servomyces, visit here.

Homebrew FAQs

What is the best way to get technical advice?
 
Please complete this simple form. Responses generally are provided promptly.

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What is attenuation?
 
Attenuation is the percentage of sugars that the yeast consume during fermentation. If the fermentation went to 1.000 gravity, that would be 100% attenuation. Understanding the different attenuation ranges of each strain will help determine the terminal gravity of the beer.

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What is flocculation?
 
Flocculation refers to the clumping of yeast cells at the end of fermentation. Strains are separated into three main degrees of flocculation- High, Medium, and Low. An example of a highly flocculent strain would be our English Ale yeast, which will settle at the bottom of the fermentation tank. An example of a low flocculent strain would be our Hefeweizen yeast.

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How important is yeast when it comes to making beer?
 
Yeast is the most important ingredient when it involves making great beer. Over 500 different flavors and aromas are derived from yeast. Many brewers spend a lot of time and money on other ingredients and forget about the importance of adding high quality and bacteria free yeast into their wort. A brewer should spend as much time if not more selecting their yeast strain as they do selecting other ingredients for their beer.

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How should I store my yeast?
 
Yeast should be stored in the refrigerator prior to use. Remove the yeast from the refrigerator approximately two to six hours before pitching and allow the yeast to come up to room temperature. The reason for this is to prevent a temperature shock when the yeast is pitched.

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Can I combine yeast strains?
 
Yes, some brewers like to combine strains for more unique flavor profiles. For example, a mellow hefeweizen beer can be produced by combining WLP001 California Ale Yeast with WLP300 Hefeweizen Yeast.
        Will there be any benefits or drawbacks from this?
Some of the benefits of blending yeast strains would be to blend flavors or aromas of different strains. Over time one strain can dominate the other so the consistency of flavors would be lost over time. If flocculation is different between the strains, it is hard to collect an equal amount of each strain.

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What is diacetyl?
 
Diacetyl is a natural byproduct of yeast. It is most commonly recognized as a butterscotch or buttered popcorn flavor in the beer. To minimize the diacetyl attributes in beer, it’s recommended that the fermenting wort rest once the beer has reached terminal gravity for 48 hours at 62-70 degrees prior to crashing the temperature. This stage allows to yeast to reabsorb the diacetyl.

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How can I increase the alcohol level in my beer?
 
Alcohol is a byproduct of the yeast cells consumption of the sugars in the wort. As the alcohol level rises in the wort, the fermentation begins to slow down. Adding yeast nutrients to the wort can give the yeast new food allowing for an extended fermentation period. Yeast nutrient also helps to create stronger cell walls, which make yeast less susceptible to alcohol death. Another way to increase the alcohol level in the beer is to add yeast with a higher alcohol tolerance towards the end of fermentation.

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Why does my beer have a high ester and/or sulfur level?
 
High ester and sulfur levels are most commonly associated with high fermentation temperatures. Different types of strains also produce different ester and sulfur attributes. Make sure you choose the proper yeast for the style of beer you are making and ferment the wort within the recommended temperature ranges.

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Why do you recommend to ferment WLP029 above 62°F?  I have seen in literature that some stains ferment at temps in the 55-60° degree range. Does this strain lends it self to lagering?
 
Some strains do ferment well in the 55-60°F, but this Kolsch strain works best at the 66-68°F temperature range. It has a very clean flavor profile at that temperature range. Some strains do not, so the lower temperatures produce better Kolsch. You can ferment WLP029 in the 55-60°F range, but we recommend against it because it is a difficult fermentation to keep going. Kosch can be cold lagered, and the flavor profile will be improved.

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How can I increase the oxygen level in the wort?
 
Most homebrewers add oxygen into wort by shaking the carboy. This can only achieve 10-30% of desired dissolved oxygen levels. Commercial brewers force oxygen into wort using an inline aeration stone. Homebrewers can find oxygen stones at most homebrew shops.

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What is the shelf life of White Labs Yeast?

Quick Answer: 4 Months
Long Answer: Yeast is a living organism. As such, it needs to be in the right conditions to survive. Dry yeast can stay alive for one year, but yeast left in liquid form, even though it's a better product in terms of taste and performance, is more perishable. At White Labs, we are constantly working on our recipe to maximize the viability of the yeast in long term storage. The longer we can make the yeast last in the vial, the better shape it will be in for fermentation. After 30 days in the vial, the viability of our yeast is 75-85%, which is very high for liquid yeast. Yeast that is harvested after a brewery fermentation will typically have a viability of less then 50% after 30 days. Our high viability is due to the health of the yeast and nutrient content of our liquid at packaging.  After 6 weeks, lag time before active fermentation is usually between 15-20 hours.  The shelf life for White Labs Yeast is four months.  Yeast used after this point is usually fine, but lag times will be longer. There will be living yeast in most vials for 6-12 months, so if a starter is made to activate the yeast, successful fermentations can be carried out with aged yeast.

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How do I make a "starter"?

A "starter" can be any volume of wort that you add yeast to before using it to make your beer.  The yeast get active in this smaller volume, usually for 1-2 days, and then can be added to 5 gallons of beer, or 10 gallons, or whatever size your brewing.  This can be a good way to "proof" the yeast, and also when making high gravity beers. White Labs recommends on their label to make a starter "if the gravity is over 1.070, if the yeast is past its "best before" date, or if a faster start is desired."  
Procedure:  
Make up a 1-2 pint wort, gravity ~1.040, hopped as normal.  Boil for 30 minutes, cool to room temperature. Pitch one vial, shake well and let sit for 1-2 days.  Little to no activity will be seen in the starter, since this is a very small volume compared to the quantity of yeast pitched.  The yeast in a starter may be done within a couple of hours. But a layer of yeast should be at the bottom after 1-2 days. The wort on top of the yeast can be either decanted of the top, or left in and pitched with the whole volume. Most pitch the whole volume, but if the starter gets to the point of 2 liters for 5 gallons, then we recommend decanting the wort off the yeast.
Typical Starter Volumes for 5 gallons:
To activate the yeast: 1 pint
To regenerate expired yeast (there will be living yeast in the package for ~1 year): 2 pints
To brew a high gravity beer: 2 pints
To brew a lager beer, starting fermentation 50-55F: 4 pints

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How can I obtain White Labs yeast if my local homebrew shop doesn’t carry it?

If your local homebrew shop does not carry our yeast, you can simply order the yeast you need off the order now section of this website.

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What is "Pitchable"?

White Labs Pitchable yeast is designed to ferment a 5 gallon (20 liter) batch of homebrew beer. We package each vial with 70 to 140 billion yeast cells, which corresponds approximately to a 1-2 liter size starter. Some of the liquid yeast on the market is packaged in small quantities, and should not be used directly in 5 gallons. Lag times are typically between 5-15 hours.

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How long does the fermentation take to complete?

Most fermentations will be complete within 14 days. Lager fermentations can take up to one month, plus aging time. The typical ale profile is to ferment very actively for 1-4 days, which is called the "exponential" or "log" phase. Then the yeast enter a stationary phase, which helps to mature the beer and can last from 3-10 days. The beer should be ready to bottle at this time. It is important to check the final gravity (FG), and calculate the percentage attenuation to make sure the fermentation is complete. If the particular yeast strain is not very flocculent, it is hard to gauge when fermentation is complete without calculating attenuation %.

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Do you have a map between your yeast strains and others?

No, we do not have a direct "correlation chart". Some of our strains are similar to those offered by other companies, but some are different. Even for the strains with similar origin, they have been obtained at different times from different locations. They are stored different, grown in different conditions and different media. Each yeast strain produced by White Labs has been carefully selected from breweries worldwide, and further selected for advantageous brewing characteristics. In general, yeast strains of similar origin exhibit similar, but not exact, properties. In our descriptions of the yeast strains, we describe the area of origin and the flavor profile parameters of each strain.

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How can I pitch 1 million cells per ml per degree Plato?

Some homebrewers now want to pitch more yeast in 5 gallons then a pint starter. An often quoted number is to pitch 1 million cells/ml/degree Plato of beer, which equals about 250 billion cells for 5 gallons. That is okay, more cells are not detrimental until about 400 billion cells. For those that enjoy yeast culturing and want 250 billion cells, one vial can be added directly to 2 liters of wort starter, and after two days of incubation, will be equal to roughly 250 billion cells. Is this necessary? Every brewer will have a different opinion, but here is some information:

a. The source of the 1 million cells/ml/degree Plato figure: Professional brewery literature.
Most professional breweries re-pitch their yeast because they have the fermentor design and facilities to reuse yeast. So most brewery pitches are actually re-pitches, and only 2-10% of brewery pitchings are using freshly propagated yeast. One of the main sources of contamination in a brewery is the pitching yeast. So in order to out-compete other organisms, large quantities of yeast must be pitched. When propagated by a professional yeast laboratory, the yeast is grown under sterile conditions, sterileoxygen and special nutrients are used to improve cell construction and performance. This does not occur in a brewery, so numbers they use to "pitch" take into account the inadequacy of their brewers yeast. The yeast is also unhealthy due to prolonged growth without oxygen and nutrients. In addition, brewers yeast will always contain some contaminants that need to be out-grown, and 1 million cells per ml per degree Plato has been found to be the best marriage of high pitching rates and no negative flavor effects (Higher pitching rates can lead to unhealthy yeast and a "yeasty" off bite). Liquid yeast grown by a professional laboratory should have no contaminants, so out competing contaminants found in the pitching yeast is not a concern.

One thing that contributes to flavor contribution in beer is yeast growth. If less yeast is pitched into beer, more yeast growth takes place, so more flavor compounds such as esters are produced. Depending on the amount produced, this is how pitching rates can have a direct effect on flavor profile. If 5 to 10 billion cells are pitched into wort, this definitely has a negative flavor impact in terms of higher ester levels and potential for bacterial contamination. But does a pint starter worth of yeast (30-50 billion cells) pitched into beer tasted different then 2 liters worth of yeast (250 billion cells)? Sounds like more homebrew has to be made to get to the bottom of this! Your feedback is appreciated.

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I am toward the end of a recent brew (bottle conditioning phase) and had a question about WLP001 California Ale Yeast. O.G. was 1.07 and I wanted about a 1.017 FG (76% atten) but I only got to 1.024 (65% atten). I want to try the recipe with the California again soon, and am wondering what I should do differently to get the attenuation to about 76%. 

The issue may be with the fermentation itself or with the available sugars present to the yeast. Even though your mash schedule may seem correct, try dropping everything in your system 10 degrees Fahrenheit. That is where you would start to see if your wort becomes fermentable. 

You could also try different base malt. For fermentation, make sure you pitch the yeast between 70-75F, then drop to a different temperature if you like after fermentation begins. Keep the temperature consistent during fermentation, even fluctuations during the evening can stall the yeast. Proper aeration at the beginning of fermentation will also be helpful. This is one thing that separates homebrewers and commercial breweries, commercial breweries have almost no problems with stuck fermentations because they have tight temperature control and they saturate the wort with oxygen before they pitch the yeast. One way to get more oxygen into the fermentor is to use a fish type of aquarium pump. Put an air filter on that you can get at homebrew shops, and turn on for one hour after pitching. Don’t use a stone, it will foam too much, just a small bore tubing, this will add big enough bubbles to mix things up, and you get good oxygen delivery into the wort. An additional tip is to transfer the beer when it gets to 1.025; the transfer itself helps to add a little oxygen and mix things up. 

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I had a question regarding the High Gravity yeast (WLP099 Super High Gravity Yeast). I used WLP001 California Ale Yeast for the initial fermentation of a 1.120 wort, and it pooped out at 1.032. I wanted to use the high gravity yeast to finish it off. Would the best route be to make a starter and aerate and pitch just like a new beer or will oxidation be a problem? 

Make a starter and aerate the starter, not the beer. That will take care of the oxidation problem and still give the yeast a good start.

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I live in India, and I recently got a couple of vials from an American homebrew store. They were in shipping for about 5 days and with an ice pack. Once they arrived, I put them in my refrigerator right away. Today, I used it for a batch of American Brown Ale I made. I had several questions about the yeast. 

1. It was not white in color, and the yeast appeared brownish.

This is normal - we package the yeast with protein and lipids to keep them healthy in shipping.

2. I shook the vial (after removing from the fridge) and left it at room temp. When I opened the vial, there was a lot of frothing.

It built up pressure during shipping and warming to room temperature. One tip is to break the cap when you first take it out of the refrigerator, while most of the CO2 is still in solution. Then vent the cap periodically as the yeast warms up.

3. There was a peculiar smell which I haven’t got from any dry yeast.

This is normal for people to think it smells different; concentrated liquid yeast will have a different aroma. When yeast grows in beer, it smells different for a number of reasons, including the presence in beer of hops. 

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I brewed this past week while it was pretty hot outside. I used my counter-flow chiller w/ inline oxygenator as usual but could not get the wort temp down below about 83 Fahrenheit. Being in a hurry I went ahead and pitched the yeast (WLP001 California Ale Yeast). Not asking for a definitive answer but how big of a mistake was this?

Thank you for your inquiry. There will be higher levels of esters and fusel alcohols but since you were able to lower the temperature fairly quickly this may not have too much effect on the final beer. WLP001 is one of the more tolerate strains to higher temperatures. Ale yeast are more tolerant to higher temperatures, lager yeast do not survive well over 80F. Ale yeast will survive to 90F. 

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I have used White Labs Liquid yeast on two separate occasions. WLP002 for a brown ale and WLP004 for an Irish stout. Using one vial in 5 gallons of wort, the wort showed no signs of fermentation after 2-3 days. Then I added one packet of dry yeast, and within a few hours, fermentation began. I am wondering why the beer doesn't ferment with only the liquid yeast? I purchase it from homebrew store, and it is kept refrigerated until it is used. Also, to my knowledge, neither had expired. 

Sometimes they just need some agitation, which is sort of what happened when the dry yeast was added. It gave nucleation sites for gas to escape and signs of fermentation to be evident. That happens a lot when fermentations don't start; you add another yeast, and soon you see fermentation. It isn't actually what was just added but the kick-start into the yeast. Both WLP002 and 004 are flocculent, and they can settle to the bottom after pitching. With flocculent strains it is even more important to stir the fermenter in the beginning. Either leaving a fish-pump type device with an air filter on for 1 hour post-pitching or stirring the fermenter a few times a day will keep the yeast in suspension and drive out CO₂.

Is WLP002 English Ale supposed to be grainy? I got the yeast out of the cooler and shook it up as I normally do, and it appeared to be coagulated. I've never used this strain of yeast before -- is this normal? 

Yes, the yeast often looks coagulated - that is the high flocculation characteristic of this yeast. You will see a similar look with our other English Style strains as well. You have to give it lots of aeration at the beginning. Shake the carboy every 15-30 minutes for the first few hours after pitching. Because the yeast is so flocculent, it gets easily caught in the trub and hops. 

I am a long-time user of your product but I am a relative newcomer to reusing yeast. About 2 months ago, I made an ESB using your WLP002 English Ale yeast. I was very pleased with the results. I made a starter and split the starter between the beer fermenter and a sanitized storage jar. I then stored the yeast in the storage jar in a refrigerator at 34-40F for about two months. I opened the jar yesterday to make a new starter for a Rye Pale Ale and I noticed a sour smell from the solution in the jar. Can I use this yeast or will it impart an off-flavor?

The sour smell can be a problem, or it can just be the smell of concentrated yeast stored for a while. The biggest problem would be a bacterial contamination, which would smell sour. If you’re going to store yeast, it is best to sterilize your glassware in a pressure cooker. The other problem would be yeast cell death, autolysis, which could also give a sour like aroma. Two months is a long time to store yeast in the refrigerator. Generally, when reusing yeast from a fermentation, half of the yeast dies in the first month. So by 2 months you only have 10-30% living cells. For White Labs Yeast, the yeast is lab grown with a special media and process, extending the shelf life. If you want to store yeast after fermentation, we would recommend a maximum of two weeks and releasing the pressure in your container every other day. Some people do go longer than that, but the results are mixed. It is also difficult without a lab to check the quality of the yeast before reusing. So, to answer your question, there is really no way to know if you can use the yeast at this point without a microscope and plates. Best not to risk it. 

I am attempting to brew with WLP002 English Ale yeast. However, the yeast production in the vial appears different from other yeast strains that I have used many times before -- it almost looks coagulated. I am worried that during transport and storage my vial spoiled? I have just placed the yeast in a starter solution to see if I will get any results. My Question is: How can you tell if a WLP yeast product in the vial is viable?

You have described our English Ale yeast to the tee. WLP002 is highly flocculent yeast and "coagulates” together; it is totally normal. You can’t tell by looking at a vial of yeast whether it is viable or not. We know from studying our yeast that the yeast has a shelf life of four months from packaging. Even after that, there is still viable yeast, but the percentage of viable cells is not considered pitchable anymore. Most brewers will make a starter when close to or after the best before date.

I am a homebrewer and currently I am fermenting a Mild Brown Ale. The yeast that I'm using is White Labs British Ale yeast. This is the second time that I have brewed this recipe. I had problems with the first 5 gallon batch because the fermentation was never vigorous. With this current brew, I appear to have the same problems.

This is normal behavior for the British yeast. You don't see that much activity because it doesn't rise to the top at all. It ferments from the bottom, unusual for ale yeast but becoming more common as many UK ale brewers have switched to conical fermentors. You should still be getting good CO2 generation, however, and that should be strong. Sometimes people rack off after a day or so, which in the case of this yeast, it would leave it all behind. It's best to leave it and not rack the beer until approximately 24 hours post terminal gravity, at the earliest. If you didn't rack, it would be very unusual for fermentation to not be complete with 70 F constant temp and good aeration.

I have just tasted some of my 005 yeast out of the vial, and it tastes sour. I just wanted to know if this is normal.

People are often surprised by the way the yeast smells or tastes out of the vial; it is hard to judge since it is a concentrated yeast slurry. It is not going to taste like beer.  The pH is also lower, so the higher acidic flavor can taste sour. You really cannot tell purity by smell or taste, although it is not a bad practice to try and become familiar with what is normal. The only way to know purity is to plate the yeast on to special media, which is what we do on all of the lots at White Labs.

I have recently purchased your WLP005 British Ale yeast, which I used in a recipe for Gales Best, which is an ale that has an OG of 1042 and a final of 1009 and a 4.5% by volume alcohol content. I followed the instruction and made a starter with the wort before pitching the yeast. The first fermentation stage I left until the gravity had dropped to about 1030 then dropped into the second fermentation stage. This stage took well over 1 month for the ale to reach its final gravity in order to barrel.

The British Ale yeast is very Flocculent, most of it probably started to settle out when you transferred the beer. So after transfer, it took a long time to bring the gravity down. English Ale Yeast WLP002 is also very flocculent. We advise to keep it in the primary fermentor until fermentation is complete. You might have to shake it once in a while to rouse it back up from the bottom and make sure it finishes. That is one possibility; others are oxygen content and temperature of formation. If the fermentation temperature gets below 65, even at night, that can cause a long and sluggish fermentation. Low temperatures will also promote more flocculation. Let me know if you have any more questions.

I purchased a WLP007 for my Dry Stout recipe.
As I prepared to make a starter, I noticed the yeast was considerably different than in the past. Instead of being creamy and smooth after shaking, part of it was lumpy. The question is, what’s going on here?

This is normal for this strain as well as other very flocculent strains such as WLP002 and WLP005. As we concentrate our yeast to a considerable degree, these very flocculent strains will look rather lumpy.

Re: WLP008 East Coast Ale Yeast

I plated 10ul from the 35ml pitchable vial of WLP008. I see two distinct colonies and was wondering if that was normal for this culture (dual strains, normal variation in metabolism)? I see mostly white colonies characteristic of yeast. I also see some small colonies interspersed. I don’t believe it to be bacterial contamination since both colony types grew at the same rate. Fermentation also appears/smells normal.

Thank you for your inquiry. It is not a dual strain, but you can see some differences when the colonies are small. Can be stress or volume size plated. 10ul is a lot of yeast to plate so there can be nutrient differences that each colony is getting. The best way is to grow a dilute solution to giant colony size; I think there would be some protocols on the web if you want to try that. When they are big you see better if there are actual morphological differences.

Re: WLP010 and 060

I made two starters, 1 pint with around 50 gram of spray malt each. They are 42 hours old. 010 seems to be active, is cloudy and is white on top of the wort. 060 seems to be finished or has not been active. 060 was not very active on the top after 10 hours but it was cloudy and now it is clear. Could it be that 060 is finished since there are yeast in the bottom and 010 started slowly?

010 is a top cropper, it forms a nice head on the top of the fermentation, very traditional ale yeast trait. 060 has some lager yeast, which ferments from the bottom, and will pull down the ale yeast with it. So both are fermenting active and normal, just a good example of yeast differences.

Re: WLP023

I have used Burton Ale yeast in the past with excellent results. I currently have a 1.078 OG beer in the primary now on the 9th day using this yeast. The first 7 days with a blow off tube. There is still some krausen and minimal airlock activity. My 5 gal recipe is 16.5 lbs of grain mostly highly modified with less than 3% adjuncts and about 10% dextrin malts single infusion mashed at 154 Deg. Aeration was good, 3 pint starter and about 2 hrs lag time. Based on past experience it should be finished but attenuation is at only 63%. Assuming there are fermentables present how can I get fermentation to resume or should I just wait it out, or call it good? I’d like to finish less than 1.020, beer's a little sweet yet. Any advice?

A. Did beer/yeast come out of the blow off tube? Burton Ale yeast is so top cropping that a good portion of the yeast could have been lost that way. Even so, the best way to speed it up now would be to transfer it into another container. That helps mix it around and break out CO2 that could be repressing the yeast. But make sure you transfer over the yeast cake as well, it is easy to leave behind and this transfer is to spurn the yeast forward, not to separate it out.

Re: WLP013

I have a 1.037 English ale in secondary which was fermented with WLP013 (@ 20C). It's still astonishingly hazy with yeast after nearly 3 weeks (2 weeks secondary @ ~10-13C ambient). Is this normally a slow flocculator?

For the WLP013 fermentation, it is not usually slow, but not much will flocculate out until it is near 4C. So you can hold it at 10 longer or drop the temperature. It is also possible that it is not a yeast haze, but a permanent protein haze. It is very hard to tell the difference, the only way to know for sure is to look under the microscope.

Re: WLP028
 
I have used White Labs yeast for years, and I recognized the benefit of liquid yeast from the first batch I made with it. I have used the "Edinburgh" yeast many times, and each time it has been great.
I just pitched a new batch this afternoon and I noticed something different about the yeast. It was darker in color than previous batches, and it did not have the very aromatic smell that I have enjoyed with previous batches.
Need I be concerned about anything?
 
The color can vary with our malt supply, but the there is no effect on the yeast. We usually try to keep it as light as possible for aesthetic reasons. 

Re: WLP029

I wonder if you could help me with my Kolsch. I'm looking to brew this as my next batch (40L). I notice from your information about WLP029 that it shouldn't be fermented at any less than 62F, which according to my calculations is 16.7C. What is your advice here?

For WLP029, people can experience problems under 16C, so we recommend that temperature, but many do ferment cooler. You just have to be more careful and keep an eye on the fermentation. With 029, you don’t need to ferment that cool anyway to get the clean flavors, you can cool it during fermentation if you like, but I wouldn’t the first time and see what you think.

Re: WLP036

It lists 65-69 as appropriate fermentation temp. I fermented lower due to literature on typical Alt production. I was at 62F. What I found is a very fast start to fermentation. Very vigorous fermentation that was totally complete in 4 days. This was totally not what I expected. This was faster than the fermentation I get with 001 or 002 (same starting gravity). Is it possible that this yeast should be fermented even lower than what your range is, or is what I experienced OK and not unexpected?

That fermentation time is still acceptable. You could lower the temp, but that is up to you. I caution two things when fermenting lower than our recommended range: 1.) sometimes the yeast will become stressed and produce sulphur and 2.) if the yeast drops out, most of the time it is a pain to restart fermentation. Just keep both points in mind.

Re: WLP051

Q. I was wondering if 051 is a slow fermenter or not. I brewed an IPA on the 5th and today is the 13th and it is very slowly fermenting and is currently at 7.5 Plato. I'd like to get it down to 3.5 Plato. The temp is at 69 and has been between 66 and 70 the whole time. I roused the yeast on the 11th and it seemed to work. Any ideas on what I should do?


A. Thank you for your inquiry. The WLP051 is a bit slower than other strains, which is one reason for its clean profile. It is also more temperature sensitive, so it might have slowed down more due to the temperature. I would rouse again, and raise the temperature to 72, there's no need to keep it low now because it is not fermenting quickly. If you can transfer the beer, do so, as this is the best way to rouse, but that is not always possible.

Re: WLP099

Q. Hello! I read with great interest your write-up on WLP099 yeast. I wonder if any of your customers have tried to make a 25% sugar wine using this yeast? I would love to see their results (and process) if it has been published.

A. People have, but we do not know of published recipes.

Q. I have some questions concerning your high gravity tips: Can a hand-held blender be used for both the initial and subsequent aerations?

A. This would not get good aeration; an aquarium pump with an inline air filter is better.

Q. In a 25L batch, what weight of yeast and nutrient should be used? Which nutrient(s)?

A. 1-3 vials of yeast would be good; 1 tablet of Servomyces.

Q. What would be the best temperature to control to, to minimize impurities? At this temperature how long would you estimate it would take for completion?

A. 75 degrees F would be good, which would take about 5-15 days to complete.

Re: WLP300

Q. I have a question about your WLP300 Hefe yeast. I brewed a hefe two weeks ago and I used the WLP300 yeast. I have used this yeast before and it worked perfectly. I think something was wrong with the last batch. When it fermented (at 69 degrees) I had a pretty good fermentation. Had some banana nose etc. When I took a sample to test the gravity it was clear! When I kegged it, the beer was really clear. When I looked at the bottom of the fermentor, it was caked with yeast cells! What could cause this? Could it be that the yeast was sitting out for about 4 hours to warm in the hot weather and got too warm? What can cause this?

A. Flocculation is not always the same with each strain, but WLP300 usually takes longer to clear, so you get a nice looking Hefeweizen. But all yeast eventually flocculate; perhaps this one sat longer in the fermentation or secondary? Did you use the wheat malt? That should give you some haze there. Some brewers will use more unmalted wheat to ensure a permanent haze.

Re: Genetically modified?

Q. I have a question about WLP400. Can you verify that it is not genetically modified?

A. None of our strains, including WLP400, are genetically modified.

Re: Differentiating between strains

Q. I have heard that Rochefort has two strains. How would I go about selecting those as two different strains (separating them)? How do you differentiate between the different strains?

A. This is a topic that is subject to a lot of rumors as well. Also, you can find multiple strains in a yeast slurry, but it can still be one strain that is doing all or most of the fermentation. If you wanted to look at Rochefort, if you had the yeast slurry you could plate a bunch of times and select individual colonies, do fermentation and taste the results. You can also do differential plates or giant colony plates but that is more involved. If you have yeast from the bottle, there is really little you can do because often you find a lot of other yeast and organisms in the bottle that are not intended to be there. 

Nutrients Section

The following questions involve White Labs yeast nutrients

Re: WLN1000

Q: What is WLN1000, the White Labs yeast nutrient?

A: Give your beer, mead, wine, or yeast culture an energy boost! Use 1/2 teaspoon per 5 gallons of beer. Store at 40-70F. Add to boil in last 5 min., or boil separately for 5 min. Shelf life is nine months from date of preparation on vial. White Labs Nutrient is comprised mostly of amino acids, which are building blocks for proteins. It doesn't speed up a fermentation much, but it does make for healthier yeast. It can be used with Servomyces.