16/01/2018
by Deborah Mitchell

DRY YEAST: WHY USE IT, WHEN TO USE IT, AND HOW TO USE IT

I’ve come across questions that seemed to plague brewers time and again. What are the benefits of dry yeast over liquid yeast? When is dry yeast a better choice than liquid? What are some things to consider when using dry yeast? In the next few paragraphs I’ll attempt to break some answers down for these questions and a few others.

WHY DRY YEAST?

Using liquid yeasts has its perks. First and foremost, the wide range of options to choose from. The available variety, all the wide offering of yeast strains listed out end up being a gift for every brewers’ creativity, a loaded palette of possible flavors and historical yeasts for those attempting to mimic or model after coveted beers the world over. On the other hand, dry yeast, due to the restrictions posed by the drying process, offers brewers a smaller variety of yeast strains. However, I think that the other benefits associated with using dry yeast make up for this smaller selection.

Dry yeast can create beautiful beer, and the options increase year after year. There are some really wonderful benefits to using dry yeast, and I will give you some of my top reasons below.

The obvious question is, then, what is so great about dry yeast? When asked, most people would reply “cost”. And this is true for a number of reasons. First, when thinking about the price you pay per cell by taking in consideration the total cell count you get in a package of dry yeast in comparison to liquid. Most of our Ale yeasts consist of a guaranteed minimum 5 x 109 cells/g. When you compare this to the average cells/ml of liquid yeast (1.2 x 109) that means you are receiving almost 4 times as many yeast cells in dry compared to liquid. If rehydrated and treated properly, this can result in some significant savings. Dry yeast producers ensure the yeast has necessary amounts of trehalose (stress protector) available to survive the rehydration process. On average, the cost for the brewer is lower for dry yeast and you get more viable cells.

When using dry yeast, there is no need to make a starter. That means your yeast is ready to go within a few minutes of rehydration, and you do not need to prepare the yeast over days in any other way. I have received questions about difficulty of rehydration before and I can assure you that rehydration of dry yeast is not only easier but it also carries less risk of contamination than making a starter due purely to exposure and contact time out of packaging and fermenter. Rehydration is simple, and you can follow our suggested steps here: http://www.lallemandbrewing.com/wp-content/uploads/2017/09/Rehydration-Ales.pdf.

Furthermore, shipping costs must also be taken in consideration, since shipping is expensive. For example, costs of shipping liquid yeast in the US can often be the same or even more than those of the yeast itself. On the contrary, shipping dry yeast is far less expensive, and these cost savings are always transferred to brewers. Geterbrewed ship yeast from America from Wyeast & Whitelabs and we know the expense involved in this is very significant

But cost reduction is not the only positive element of dry yeast. Convenience is certainly an excellent additional perk. Take oxygenation as an example: simply put, it is not necessary to oxygenate/aerate wort upon first pitch of Lallemand Brewing yeast. We have already taken that step for you during the propagation and production of our yeasts, ensuring that each cell has the proper amount of sterols and lipids needed for healthy fermentation. The convenience of taking the oxygenation step out of your brewing process is helpful for 2 reasons: 1) it will save you money on oxygen; and 2) it will simplify your production process. Additionally, since you will have fewer cell divisions (and new cells created) due to skipping a respiration phase, the amount of nutrients and trace minerals (essential for healthy fermentation) present in the initial wort will not be shared with times as with liquid, making for consistent fermentation and guarantee that your cells have what they need to do their job properly. When repitching Lallemand yeasts, please oxygenate the wort as you would for any liquid yeast.

Thanks to this convenience element and due to the longer shelf life of dry yeast (often ranging from 2-4 years from package date), it can be easily ordered in advance and stored in a cooler, leaving it there, readily available, and waiting for brewers to use.

When considering stress protectors, the availability of trehalose in Lallemand’s dry brewing yeast is particularly helpful when attempting to ferment beer in stressful conditions. Among other factors, stressful conditions can include low pH, limited availability of nutrients, high gravity, and temperature; all these can (and certainly will) appear as brewers continue to push the limits of style. So next time you are kettle souring or making that high gravity stout consider a robust dry yeast for your fermentation.

I would love to also take this opportunity to provide some answers to common questions we receive about our products:

CAN I REPITCH DRY YEAST?

Yes. Once rehydrated, you can use dry yeast just as you would liquid yeast. As long as you keep the yeast clean and healthy it can be reused just as you would for any other yeast; it is, after all, the same living organism. However, with any yeast (liquid or dry), if repitching yeast is the way you’ve chosen to go it is important to provide it with the necessary nutrients for healthy fermentation .

WHEN SWITCHING YEASTS WHAT ARE SOME THINGS TO CONSIDER TO MAINTAIN CONSISTENCY OF PRODUCT?

It's important to understand that there are multiple variables when working with brewing yeast. When switching yeasts it would be advisable to try keeping all other variables the same: mashing and fermentation temperatures, pH, inoculation rate, and wort composition are just a few variables to try and keep in mind. This way you will be able to notice the changes in fermentation kinetics and flavor differences when switching yeasts. Once you do this you will be able to adjust the other variables as necessary so as to achieve the exact flavors you are looking for.

WHAT ARE SOME TIPS FOR BEST YEAST MANAGEMENT

Our suggestions include:

· Keep everything sterile when working with yeast; this is the most important tip for proper yeast management.

· Minimize the time yeast is in contact with non-sterile environments, and limit contact with air/oxygen when pitching.

· Do your research on proper inoculation rates for the style you are attempting to make.

· Have a proper understanding of how each variable can affect the final flavor in your desired beer style:

o Just a few degrees changes in in temperature can create an entirely different flavor profile. This versatility is precisely the beauty of dry yeast; one single strain can be manipulated by a skilled brewer to achieve a large variety of beer styles and flavors.

o Factors, such as low pH or high gravity, can stress yeast and contribute to unwanted esters and phenolic flavors.

So our suggestion is a simple one: keep things as clean as possible and experiment with each variable to work to get the flavors you desire. Also, if making a high gravity beer it's important to ensure the yeast has the essential nutrients that it needs for a healthy fermentation. Also, when in doubt, reach out to your technical representative! This is why we are here; it is our job and our passion to help you achieve your fermentation goals.

WHY CHOOSE LALLEMAND?

Supported by long-standing industry experience, an extensive support network, and strong technical expertise, Lallemand Brewing is perfectly positioned to help breweries achieve their most ambitious growth and quality goals by offering products, services, and education suited to fit your brewery’s needs, regardless of size. I hope this has provided you some insight into the world of dry yeast and answered any why, when or how you may have had regarding our products. Again, please do not hesitate to reach out with any questions you may have at brewing@lallemand.com . You can check out our full selection of dry brewing yeasts and bacteria, along with many other brewing related products services and educational offerings online at www.lallemandbrewing.com .

Cheers to great beer,

Caroline Parnin Smith

East Coast Technical Manager, USA