Before I begin, I would like to say that I am sorry for the number and quality of pics that are in this post. Being my first time washing yeast, I hurriedly only snapped a couple pics because I was afraid to mess something up, and because I obsess a little over sanitation (yes, I know, my kitchen is messy, but anything that touches anything is extremely clean and sanitized). Ideally, I would have had someone else take pictures of the process as I was doing it.
Basics first: Yeast washing is reclaiming yeast from the yeast cake that is left in the bottom of a fermentor, after fermentation. This yeast is, usually, healthy and can be reused around ten times before significant mutations cause undesirable effects to your beer. This is a great way to reduce the cost of your beer, especially if you are using lager and/or liquid yeasts (or even dry ale yeasts, with the way prices have been rising on those). Although yeast washing may seem intimidating, the process is actually simple, as I found out earlier this evening.
The point of yeast washing is to separate the yeast from the other matter in the trub. The other stuff in the trub usually includes adjuncts, proteins, fats, hop bits, and anything else that comes out during the hot and cold breaks that makes it into the fermentor. Yeast washing removes all of that extra stuff that you don’t want to add to your next batch of beer.
Yeast washing differs from acid washing in that with acid washing, acid is added to lower the pH to 2 for a period of time to kill any non-yeast microorganisms that might be present. This also severely stresses out the yeast, and usually kills any yeast that are not in tip top shape.
- 1 qt wide mouth mason jars (I bought a case of 12 from my local grocer for $11)
- a pot to boil the mason jars in
- a fermentor full of beer ready to be racked/bottled
The night before racking/bottling the beer:
- Boil 4 mason jars, 4 jar rings, and 4 lids in a heavy, rolling boil for at least 10 minutes
- Put the lids and rings on the jars full of hot water
- Put the jars into the fridge to cool overnight (we don’t want to kill the yeasts with hot water)
On racking/bottling day:
- Sanitize the container that you are going to rack into, then save the sanitizer in a bucket/tube to use while performing the yeast washing
- Transfer the beer as normal, being extra careful to keep the opening of the fermentor as covered as possible (especially if you are using buckets)
- Take 3 of the mason jars with the boiled-and-chilled water in them, and carefully dump them into the fermentor. As you dump each one into the fermentor, put the jar in the sanitizer so that the mouth of the jar is facing downwards, and put the ring and lid in the sanitizer.
- Cover the opening of the fermentor with the bucket lid or bung and swirl the water to suspend the trub in the water
- Place the 3 empty mason jars mouth side up in your sink (to keep any mess from spilling contained)
- Pour the trub-water solution from the fermentor into the 3 jars (you will have more stuff in your fermentor than will fit in these jars, don’t worry about it)
- Cover the 3 mason jars with the lids and rings that have been sitting in the sanitizer
- Let the jars sit for around 15 minutes to let the yeast separate from the unwanted trub
- Take the 4th mason jar and dump out the water. Put the ring and lid in the sanitizer.
- From the three mason jars, you want the third of the liquid that is just above the bottom layer of settled out crud. For each of the 3 jars, pour the top part off down the drain, then try to pour the desired part into the 4th jar without including any of the crud at the bottom. Don’t worry if you aren’t perfect, this isn’t an exact science.
- Put the lid and ring on the 4th jar, and put it in your fridge, ready to be pitched into your next batch of homebrew!