Dry Yeast vs. Liquid Yeast

We all know the saying “Brewers make wort, yeast makes beer.” We can do all we want to the wort, we can throw in any amount of additives or hops we like, if still isn’t beer until the yeast does its thing.

Yeast has changed over the years. The quality of the dry yeast that was 10-15 years ago was fairly poor, and the selection was miserable. Dry yeast was tossed into the prepackaged brew kits, and in some cases wasn’t even the proper yeast for the kit. In the 1990s, liquid yeast began to emerge as the most popular yeast for brewing, with companies like White Labs and Wyeast providing vials and smack packs in a variety of types. By the early 2000s, liquid yeast was the premier type.

Now, dry yeast is beginning to make a comeback. Traditional yeasts such as Munton’s and Cooper’s are still out there, joined by offerings from companies such as Lallemand, Fermentis, and more. But is there an advantage of using one yeast over the other? Let’s take a look at how dry and liquid yeasts match up.

Variety

While dry yeast has expanded in terms of variety, it still has quite a ways to go to catch up to liquid yeasts. White Labs alone lists nearly 80 strains of liquid yeast available, while Fermentis only has a dozen or so dry yeast strains. So if you need that particular Belgian Strong Ale yeast from a particular region of Belgium, you’ll need to go with liquid. If you just need a plain old ale yeast, you can get that in both forms.

Expense

A packet of dry yeast will generally cost half as much as a vial or smack pack of liquid yeast, meaning that large batches or needing more yeast will increase the price exponentially. This can get even worse should you experience stuck fermentation and need to pitch a new starter, at which point you would again need to buy another vial or smack pack instead of the cheaper dry yeast.

Efficiency

When it comes to pitching yeast, you need to know how many yeast cells are needed. Even the prepared, ready-to-go smack packs that have 100 billion cells may be underpowered, and may need a starter. It may even require a second pack of yeast, doubling the expense.

Dry yeast is much denser than liquid yeast, though, and it contains more cells per gram. This means that one gram of dry yeast will provide more active cells than a gram of liquid yeast. The major advantage here is that, if you calculate you need an odd amount of yeast – say, your ale will require 156 billion cells for proper fermentation – you can simply measure out the appropriate amount of dry yeast, figuring on 18 billion cells per gram, add it, and you’re good. An odd amount of liquid yeast will require creating a starter, buying multiple sizes of packets, and likely being a bit short or a bit over.

Shelf Life

Shelf life is also referred to as viability, as some of the live yeast dies off over time, reducing the effectiveness of a package.

A vial or smack pack of liquid yeast generally only has a shelf life of 6 months or so, and that’s only when refrigerated. It’s not a finite point, either – the viability rate drops immediately, losing 20% in the first month. At 6 months, the pack or vial is only around 25% viable, meaning you will need to create a starter to get usefulness out of the yeast.

Ease Of Use

Dry yeast is a breeze to use – hydrate it in lukewarm water for around 20 minutes before pitching, at a rate of 50 milliliters of water per 5 grams of yeast, then dump it in when ready. It’s that simple.

Liquid yeast, particularly in vial form, will need a starter to kick-start the process, as well as for particular situations such as high original gravity and out-of-date yeast. This requires prepping the yeast a few days ahead of time, as well as needing equipment such as a magnetic stir plate, flasks, and more.