Monday, March 19, 2007

Simple Yeast Washing

Urban Brew Gear and Whatevers
Yesterday, in the city I picked up a nice stainless steel strainer, a Pyrex 2 cup measuring cup, a small funnel and some isopropyl alcohol for cleaning lips and rims when propagating yeast. I also looked at Ace for some basic plumbing items for the home brewery. Don't get me wrong I love hardware stores, but today we're off to Chinatown!

I have been doing lots of reading and listening to podcasts on yeast and how yeast live. Yeast is such a magical ingredient in making beer and I now know so much more about our simple celled friends. I am happy that so much fabulous information is available in the net. Paper, books and libraries worked for 1000 years, but the Interent is becoming so multi-media.

It's 9AM...Where is your yeast?Washing Yeast
I learned originally from Oz Craft Brewer how to wash yeast. Washing yeast involves collecting the trub (pronounced troob) from the bottom of your fermenter. After the initial fermentation is complete there is a whole bunch of sediment in your brew vessel.
If you sanitize two 1 litre canning jars (or similar) and carefully scoop the sediment from your fermenter into the jars. Don't let your dirty fingers or even fingerprints touch the liquid. Cover the jar with a small square of cling wrap and refrigerate.

In the next day or two it will magically separate. There will be a layer of beer, then a small layer of yeast, then a layer of heavier sediment. See the diagram.

I have read about acid washing yeast which involves lowering the pH to kill bacteria. The pH is lowered to about 2.5 and then the yeast is washed off. Yeast likes a lower pH environment, but a pH less than 2 will kill the yeast. Adding a drop of acid at a time and checking with the pH meter is required. Acid washing is something I could not be bothered with; maybe if my precious strain was to be infected.

I've done some trub collecting/yeast recycling before with Saflager's S23 dried lager yeast and I enjoyed more than five sucessful batches from the same 11.5g package of yeast. Ok, yeast is cheap to buy, but it takes about 2 weeks to get here from the US via airmail and I can brew two batches in 10 days di ba? Having said that; I have enjoyed Munton's, Cooper's and a host of other ale yeasts but never thought to preserve them. Shame.

(As a side note I have some champagne... (18% Alc./Vol. tolerant yeasts and some white and red wine yeasts brought in too.) I have a nice libraray, but its a job looking after them.

Liquid yeast packs from the US are risky. Long shipping times (10 plus days air frieght) and high temperatures of the topics make not for a 'yeast friendly' combination. Some homebrew shops will suggest shipping liquid yeast with an ice pack. Ice packs are okay, but only for a day or two maximum. If a homebrew shop in the US says "Yes! We ship to the Philippines", please don't expect anything living to make it to the Philippines in its life-full state.

Yeast Library
What we should be doing is getting a nice library of yeasts and sharing them with associates in the Philippines. I'll give you mine if you give me yours sort of thing. In the future, I will deveolp a very clean system and make some strains available here.


Coffee time.

No comments: