homebrewandbeer.com

Was just reading through the FAQs and came across thet question... and it truly intrigued me.

On and off I was pondering the idea of using yeast from the lees of my favourite store-bought beers to brew with, thougfh was unsure as to just what would happehn, and I didn't want to risk wasting a batch in the interest of an experiment. Now that I have read that, I'm giving it serious consideration.

My preferred brand is Unibroue, a brewery in Quebec, Canada that focuses on Belgian-style brews, and is reknowned as one of the top ten breweries on the planet. Their beer comes in a big 750ml bottle, and each one is on lees. These are live brews...

So, if I pitch some lees from these delicious beers into a fresh batch of wort... is there a decent chance that I will get the effect of the yeast from these beers working in my favour?

you're on the right track, but you're effectively sitting a baby in front of a giant mountain of food and saying "eat it all".

you need to work the yeast up slowly. this is easily done, you just need to be sanitary. the 750ml bottle should do fine to get it started. you're basically giving it a tiny batch to eat through to grow bigger, in a couple steps.

rough guide: use dry or liquid malt and water in roughly a 1 part malt to 10 parts water ratio. start it on maybe 100ml worth of this mix, which has been boiled to sanitise, and cooled with the lid on. sanitise the outside around the cap of your unopened bottle of beer, open it, carefully pour out the beer, leaving the last half inch or so with the sediment. carefully pour in your cooled 100ml of wort. gladwrap and a rubber band over the bottle top will keep it clean, yet still allow CO2 to escape.

give it a damn good shake to aerate it, and leave it somewhere warmish (20c range - room temp). every time you walk past, give it a good swirl. you MIGHT see some small bubbles around the edge of the liquid surface indicating action, but you should notice the yeast volume increase slightly. the yeast should be a healthy creamy colour that dissipates easily into the beer - no chunks lol.

once this is done, step it up into a larger bottle, e.g sanitised 2L coke bottle, and fill it with the 10:1 water/malt mix about 3 quarters full. let it feed through this, then once it seems as though it's eaten it all (hydrometer reading over a couple days is stable), pour off the cleared 'beer', and pitch the yeast sediment into your brew. before doing this, take a taste of the beer you poured off. you'll know if you've failed and got an infection

using a big mixing spoon, aerate the crap out of your brew once you've done that. also, pouring the water/wort from a height to splash it into the fermenter will help aerate it. this helps the yeast to get a quick start.

Thank you kindly for that advice! Certainly makes a little more sense than simply chucking in the sediment and hoping for the best in 23 liters worth of prepared wort, heh.

you're welcome. keep us posted on how it goes. i've recultured a few times now (when i can be bothered, for something fancy), and had good success. i've also had one turn nasty. sanitation is very important. when dealing with such a (relatively) small count of viable yeast cells to begin with, it only takes a tiny slipup for an infection to take hold. clean and sanitise everything