A yeast nutrient is a blend of supplemental nutrients added to the fermentation to make sure the yeast has enough nutrients such as nitrogen, amino acids, vitamins, and fatty acids in order to reproduce and form a healthy yeast colony.
These added nutrients ensure that the fermentation is healthy and finishes at the targeted final gravity. If these required nutrients are lacking in the wort or must you can run into problems during fermentation or in the worst-case scenario, the fermentation does not even begin in the first place.
There are a few companies that manufacture yeast nutrients and all of them have a slightly different makeup, however, most of the products on the market will include the following nutrients:
1) Yeast hulls sometimes referred to as yeast ghosts. They are exactly as they sound, remnants of previous live yeast cells. These dead yeast cells contain many of the nutrients that live yeast require to grow and multiply.Amino acids are used by live yeast cells to create protein and reproduce. Many of the essential amino acids the yeast require will already be in the wort or must however if they are lacking it can negatively affect the fermentation. By adding some to the mix you will ensure your yeast are healthy and doing their job effectively as possible.
2) Zinc is another important mineral that is required during fermentation. It plays a significant role in the production of ethanol. Without ethanol being produced you are not going to make alcohol. In many worts or musts, zinc levels can be lacking, there is no simple way to test the zinc levels so by adding some you can rest assured your fermentation will produce the ABV % you are aiming for.
3) DAP or Diammonium Phosphate, if you are a gardener you may be familiar with this water-soluble salt as it is usually a prime ingredient in many plant fertilizers. In plants, its role is to raise the level of the PH of the soil. During fermentation, it raises the level of phosphate and nitrogen which ensures the yeast cells have enough to complete a full fermentation.
4) Various Minerals & Vitamins. You will note that different yeast nutrients on the market have varying types and amounts of minerals and vitamins such as potassium, calcium, and magnesium to name a few. All of these nutrients play important roles in making sure the yeast performs its various jobs effectively.
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When to Add Yeast Nutrient?
You don’t always need to add a yeast nutrient, however, knowing when to add some is an important skill a brewer needs to acquire.
To start with, if a recipe calls for it then use it, however sometimes even if the recipe does not call for it you should use some.
When it comes to making beer in most cases you do not need to add any yeast nutrients as most of the wort you produce for beer is rich in the nutrients the yeast requires. Having said that if you are concerned, using some will not hurt the batch and will ensure fermentation runs smoothly for you. If you are finding you are not hitting your final gravity then try adding some nutrients next time and see if that helps.
If you are brewing a big beer with an ABV above 7-8% it is recommended to add some nutrient in order not to stress out your yeast and have it stall on you. When making beers that have a large number of adjuncts it is also important to add a nutrient. This is because most of the fermentables from these adjuncts come from sugar, which does not contain the nutrients yeast requires.
Another time it is recommended to add a yeast nutrient is when you are making yeast starters. The key to making a good yeast starter is to get the yeast cell numbers up high and in order to do this, they require lots of nutrition.
And lastly, if you are making wine or mead you will want to always use a yeast nutrient due to them not containing as many nutrients as the barley and wheat used to make the wort for beer.
The fermentables for wine come from the grapes which is a simple sugar, and the fermentables for mead come from honey which is also a simple sugar. Because of this, the yeast requires additional nutrients in order to multiply and do their job of fermenting the batch properly. The same goes for making cider.
How Much Yeast Nutrient per Gallon?
It is our recommendation to use a yeast nutrient from one of the major suppliers and each of them will indicate on the package the amount to use per batch size.
On average you will use 1 tsp per gallon (5 liters).
When to Add Yeast Nutrient to Wine?
Most winemakers will add the yeast nutrient as soon as they pitch the yeast. Others add it at varying times throughout the fermentation. Usually at the start of fermentation and then again one or two more times during fermentation. In our experience having more than one addition is not usually required but test it for yourself to see if you get better results.
When to Add Yeast Nutrient to Beer?
As discussed the only time you need to add yeast nutrient to beer is when you are brewing a high gravity beer or a beer with lots of adjuncts, typically if the adjuncts are 25% of the fermentables or higher.
When you add the nutrient you can do so directly into the boil, typically 10 minutes left. Some claim this ensures the nutrients are sanitized and will be evenly distributed throughout the wort. In our experience just like making wine, you can add it at the start of the fermentation when pitching the yeast and it will work just fine.
When to Add Yeast Nutrient to Mead?
When it comes to making mead most brewers used to typically just add the nutrients at the start of fermentation. However in recent years more and more mead makers are claiming that staggering the nutrient additions is resulting in a higher quality mead.
They use the same amount of nutrients however divide it into smaller additions. Most will add the first addition at the start of fermentation and then 3 more additions over the course of the next 3 days. They claim this ensures the yeast is as healthy as possible during fermentation and results in fewer off-flavors being created.
Frequently Asked Questions
What can be used as a yeast nutrient?
It is recommended that you use a yeast nutrient from one of the well-known manufacturers of them such as White Labs and Wyeast, however, some people do use the following items as a substitute:
- Orange, lime, or lemon juice.
- A cup of raisins (chopped up)
- Bananas, but you need to mash them up, then boil them and strain off the bananas, the leftover liquid is the nutrient.
- Boiled rolled oats and grape nuts
There are also many recipes on the internet for making your own yeast starter.
Is yeast nutrient necessary?
For beer, it is not necessary unless you are brewing a high gravity beer or a beer with lots of adjuncts. For wine, cider, and mead a nutrient is recommended.
Are raisins a yeast nutrient?
Many people do use them and the idea of doing so has been around for hundreds of years. Our thoughts on this are that they are ok when you are in a pinch. However, they are not an ideal nutrient substitute as they only carry very small amounts of Amino Acids and Vitamin B and not enough to provide what the yeast requires for a good fermentation.
A yeast nutrient is an excellent way to provide the nutrition yeast requires for a healthy fermentation. When making the majority of beers the wort itself will have all of the nutrition the yeast requires so adding a nutrient is not required. However for beers with a higher ABV’s and adjuncts you might want to consider adding some, and it is always recommended that for wines, ciders, and meads that you use a yeast nutrient.
P.S. Want some new beer recipes? Check out the side of the blog or the bottom if you are on your smart device and get access to my top 5 recipes from my brewpub. Cheers!