Brewing with yeast in YPD media

I wondered if anyone has any experience brewing with yeast grown up, kept and stored in YPD media. I’m wondering if the yeast extract or peptone impart any noticeable flavor to the beer. I’d love to start saving my yeast for future brews.

Funny I see this now, I am sitting at my bench in the lab I work in and I have two 500mL cultures centrifuging now. I grow my cultures in YPD, I go from a freezedown in 15% glycerol, spear a little with a sterile loop into 5mL YPD overnight at 30*C on a shaker, to 50mL overnight, to 500mL overnight, then spin it down and resuspend the pellets in about 40mL of the spent YPD, then just dump that into the primary after aerating. I think I am way overpitching, but my beers come out well and don't taste strange. I figure 50mL in 5-gallons isn't enough to affect the flavor.

if only we all could

Thanks so much Colorado! Your process is pretty much along the lines of what I was thinking about. I worked with yeast when I did my undergrad and still have access to all the requisite supplies and equipment (along with a -80) where I'm at now, so I was having a hard time seeing paying for the same strain more than once. Jetsers, these little guys grow and store so well in the right media that it's really not hard to do with even some basic equipment. I've kept stuff alive and viable for years at -4 degrees F (normal kitchen freezer).

Jetsers said:

if only we all could

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Yeah, its gonna suck when I go work for big pharma and can't do this stuff anymore...

I also work in a lab and have access to ypd here, but I'm hoping to draft some growth curves using a growth media that can be easily replicated at home. We work with pathogens in lab and I'm not interested in bringing my yeast samples in/out, but I can run experiments on them in lab then replicate them at home. Any ideas on a good growth media to use from common house hold goods? Are there cheap alternatives to yeast extract and peptone? Thanks,

-Alan

I have recently finished reading Yeast: The Practical Guide to Beer Fermentation by Chris White and Jamil Zainasheff I would like to try my hand at freezing yeast at home, but as I don't have a background in Microbiology or similar there are a few things I'm unsure about:

Is there anywhere to buy cell culture supplies without breaking the bank? So far, the stuff I've seen is a bit pricier than I'd have liked! The protocol they suggest uses YPD broth, glycerol and ascorbic acid. Also, when looking at options, I'm not really sure what's required in terms of purity/grade etc. I understand that everything has to be sterile, but rather than buying sterile supplies (which I might struggle to keep sterile once opened as I don't have a laminar flow hood or the like), I thought I could sterilise media and glycerol myself, either by "autoclaving" in a pressure cooker, or by sterile filtering - is that a good method? Or will that turn out to be an expensive option? I remember sterile filtering things with a syringe a filter when working as a technician years ago, and as I only do small volumes, this was what I was planning on doing. Perhaps I should mention I live in the UK, but don't mind buying stuff from over-seas!

The protocol says to "...pick a culture and grow it in 10 milliliters of medium for 48 hours... move the 10 milliliters culture to a 40° F environment , and hold for another 48 hours, to encourage the yeast to build trehalose..." I assume this means picking a colony from a plate or slant and propagating it before proceeding. I intend to buy packages of liquid yeast, and split and freeze them. Should I still propagate the liquid yeast prior to freezing in order to build glycogen and trehalose? Or can I go straight to the next step? How many cells should I be using? Based on the cell count given by the manufacturer I can would out how much to use to equate "a culture".

If there are any other tips or advice anyone with a bit of experience in Microbiology can offer, it would be greatly appreciated! Thank you!

Dennis