Of these last two methods, the sterile water storage method seems to be the most practical, most preservative technique of all those available to small-scale brewers. Or better yet, make a yeast starter, especially if the yeast has been in your fridge for more than one week. Armed with a firm grasp of sterile technique and a bit of practice, you can securely maintain many cultures using a variety of methods. Roughly two weeks (assuming each jar or growler has fermented out) it should be safe to taste. Years later Charlie P was visiting the Sandlot Brewery at Coors Field and ran into HBT user @Wayne1, who gives us the original recipe for Blue Moon (you can also get it more or less in Hieronymous' Brewing with Wheat), who took the accession number and called over to the microbio lab to get the background on the yeast. As with anything, proper yeast management is key. Remove your cotton swabs and dunk/swirl the swab end into the starter wort several times until the swab is fully saturated, and any dust on the swab has made it into the wort. Check the slurry for aerobic and bacteria, and wild yeast. A yeast sediment will eventually form at the bottom. Don’t use the slurry if bacteria counts are over 1 per ml, and wild yeast is over 1 per 0.1ml. Only pour enough to cover the fruit or vegetables, but leave enough room for fermentation activity at the top. Cover with cheese cloth (to prevent insects from crashing your yeast party) and keep in place by screwing on the jar lids or tightening with a rubber band. Place it in the fridge. Matthew Farber, director of the Brewing Science Certificate Program at Philadelphia’s University of the Sciences, says, “To the port a brewer should clamp a sight glass followed by a t-pipe fitting with valves on each side. Of course, you may in the future want to cultivate Lacto to have your own sour strain. Place the jars overnight outside, in a herb or vegetable garden, under a fruit tree or even in your beer cave. Cap the jar again with the same lid and put the screw cap on it. Once the 5-mL culture has reached high kräusen (at about 24 hours), use it to inoculate 50 mL of wort. Boil the liquid mixture with a small amount of hops for at least 20 mins. Ideally, you’ll use yeast that is more than 95% and no less than 70% viable. The materials requirements are modest (see box above “What You Will Need”), and the rewards — especially if you chance upon a rare or exceptional yeast strain — can be immensely satisfying. Ideally you should use it within 1-3 days. Let the alcohol evaporate then sanitize the top of the bottle to kill any microorganisms that were hiding underneath the cap. If it smells good, use a sanitized pipette to pull a sample from underneath the surface. The presence of mold doesn’t mean your wild yeast starter is ruined, it’s just a common part of the process. On brew day, take the washed yeast out of the fridge and gently pour off the liquid, leaving the yeast behind. To, The @northseattlehomebrewers and @stayhomebrew kno, A new class of yeast wranglers are heading out int, Love getting to try beers made with Bootleg cultur, New Blog Post Alert! Never taste any starter unless active fermentation has been verified for a sustained period of days. I discard the first vial and then check the second vial for contamination. No other method allows you to store cultures in a stable state for such long periods of time. Third, if you seal the slant tightly and keep the yeast at 39 °F (4 °C), the yeast will remain viable for several months (at least two), allowing you to use it again in subsequent brewing sessions or to give it to a friend. To reduce the likelihood that I will lose a culture, I make three vials of each culture and use the first vial exclusively until it becomes contaminated. To prolong life within this time span, keep the yeast at 34-36 degrees in a dark space free of oxygen. Note: Don’t harvest from problematic fermentations. Within a few days you should see signs of fermentation taking place. Download the free Precision Fermentation white paper, “The Connected Brewer: Data-Driven Fermentation for Better Beer and Better Business.” Can fermentation management be improved, as a process? Contamination control: Repeatedly opening the vial to start up cultures year after year will eventually lead to contamination. In order to encourage yeast activity, keep the new bread starter in a warm environment, at least 70ºF (21ºC). Don’t let the trub and yeast pour through the port too fast or you’ll end up with tunneling. Gathering the yeast. You may keep the pitching volume in the refrigerator for up to one week (disinfect the outside before you use it to pitch), but at the expense of increased lag time, which may end up adversely affecting your beer. No part of this document or the related files may be reproduced or transmitted in any form, by any means (electronic, photocopying, recording, or otherwise) without the prior written permission of the publisher. Within a few days you should see the normal signs of fermentation. In an open vessel, cropping should happen once gravity has fallen at least 50%. However, because they don’t vent pressure, shake and vent the kegs once a day or more and vent the buckets periodically. Before storing and again before re-pitching, brewers should test their yeast for viability and contamination. Yeast culturing is not for everyone, but the satisfaction that comes from being involved at this level of the production of your beer is worth the extra time and effort. See, wasn’t that easy. Farber explains tunneling this way: “If, during transfer, a valve is opened too far, the yeast slurry flows too quickly, pulling yeast from the center of the cone. Measure out your DME and place it aside. After two days, the mixture may look bubbly or foamy, and take on a noticeable smell. After another 24 hours, your 50-mL culture should be in high kräusen and ready to use to inoculate a 500-mL culture. If it smells good (honey, citrus, etc), you’ve probably got something fun. Don’t worry if you don’t see signs of activity quickly. Pour off the beer slowly, leaving behind the sediment at the bottom. It’s not necessary for fruit to be crushed for fermentation to take place. Swirl it all around to create some mud. Don’t harvest yeast from beers with higher than 6.5% ABV. If the second vial looks good, I use it to make a fourth vial. Download here ». This will help reduce the chances of surface mold growth. Wipe down your bottle with 70% ethanol solution or isopropanol.