Repitching yeast method

A few weeks ago I came across the yeast re-pitching method described below. I used it yesterday, I pitched about 1 1/2 cups of slurry. Within 12 hours I had very active fermentation. This method seem a little easier than other methods I have seen on the web or read. Has anyone used it with any success? Any thoughts?

REPITCHING YEAST
Using liquid yeast rather than dry yeast gives the ability to produce beers that are professional-quality, if not even better. Using liquid yeast also gives you the ability to repitch the same yeast for 2 or 3 batches. Repitching your yeast is incredibly easy.
When you're ready to transfer your wort from the primary fermenter, sterilize a glass jar, including the lid. (A mason jar is ideal.) Siphon all but the last 1 inch of beer from your fermenter. Swirl around the slurry and remaining beer in the bottom of the fermenter and then sterilize the mouth of the fermenter. Pour the contents of the fermenter into the sanitized jar. Replace the lid, leaving it a bit loose to allow any gases to escape, and then place the jar in the refrigerator.
When you're ready to pitch the yeast for your next batch take the jar out of the refrigerator and allow it to come to room temperature. Remove the lid, pour off the top layer of beer, and flame the mouth of the jar. Swirl around the contents and pour it into your fermenter. Yeast that is being repitched should be used within two weeks to ensure good quality.
A couple of things to remember: First, keep things sanitary. The yeast is still very susceptible to infection. Second, repitch only liquid yeast. Though you can repitch dry yeast, the chance of infection is increased each time you do, so it's just not worth risking your batch of beer.

One downside of this method is that you aren't "washing" the yeast, so the trub from the previous beer will be mixed into the yeast slurry. You will be pitching the trub into your new wort.

But this isn't any different than pitching onto a yeast cake, which many people do. I don't use this method because of the trub.

I did that for some time with no ill results.

I am not sure why it says that you cannot do it with dry yeast. I would think the chance of infection is the same with dry or liquid. It's just that dry is cheaper so it's not really worth doing.

I've done this before with dry yeast and it worked great. Fermentation started after 4 hours. When you're using this method make sure the yeast you're reusing is from a lighter beer than the one you're pitching to. It doesn't work as well if you go from a high alcohol beer to a lower one.

The argument that dry yeast is more susceptible to infection does not make sense to me, but yes this will work. Also, you'd be better off washing your used yeast:

Yeast Washing Illustrated

Just makes things a bit cleaner, leaving trub from an old batch out of your new batch.

I only use about a half cup of the yeast slury for a 5 gal batch. I worked the numbers on the pitch rate for a while but ended up with the half cup on almost everything except very high gravity brews. You would get a rocket start and ferment but the danger is that you are over pitching and would end up with too great an ester production. All considered, see how it turns out...success is proof enough in my book!

I just did (more or less) the same thing recently with a batch and had some issues. fermentation never took off and I ended up have to pitch 3X. I think the yeast was perhaps not as viable as I had thought.

I let the Previous batch ferment for 3 weeks then stored the yeast in the fridge for another week. after pitching the third 2 cup sized mason jar it finally started fermenting, but seems kinda weak and I haven't seen the temp in the fermentor go up like I usually do.

my question is did I wait too long either by storing for a week in fridge or maybe I should've secondaried to get more viable yeast? I mean was my yeast just that tired out?

I know alot of people will come back and mention starters but I'm not ready to start doing that just yet. also this was dry yeast (US-05) and the second time I re-pitched it.... that, is I used it once out of package, then on an amber and this time on the same type of amber.

You already know the response. I ALWAYS use a starter and make sure the I give the starter lots of 02. Do it once and you will know it is worth the effort.

Update: Three days of strong fermentation. I have never seen the air lock bubble so quickly. Very nice aroma in the room. I plan to let it go for about 10 days then keg. Also, I made a 2 liter starter with the yeast (WHITE LABS GERMAN ALE/KOLSCH - WLP029) when it was used in the first batch.

I think it depends on how long you keep your yeast slurry before repitching.
If you are going to brew a new batch within a week or so of harvesting the slurry, then I think it would work. If you are going to have to keep the yeast much longer, I would wash the yeast, and use a starter to step it up for the next batch.
If you analyze what I said, you will notice I used "I think", and continued with "if ... I would ... "
What "I think" means is that I have done this on several occasions, and have not noticed any bad side effects.
"If ... I would ..." means that's the way I have done it successfully, which is not to say that is the only way to do it.
You may want to check out https://www.homebrewtalk.com/f163/why-not-pitch-your-yeast-cake-166221/ - post 1 which (to my simple mind) seems to confirm what I said.

-a.

Update: so far so good. Gravity down to 1.012 after 10 days. No off flavors or aromas. Very clean, smooth taste. Plan to keg today and force carbonate.

last update: Great tasting beer. Smooth, malt flavor come threw, very little hop flavor or aroma. I would categorize this as a success. Plan to use the method again.

Found this thread so decided to BUMP:

I plan on using this same yeast pitching method tonight. I bottled an american wheat last Sunday (1.040 OG, 1.006 FG) and plan on pitching into a 1.048 honey weizen. I saved the equivalent of 2-16 oz mason jars worth (including the layer of beer). According to the Mr Malty calculator, I should pitch 92 ml of slurry. Few questions:

1) Is this 92 ml of slurry after the beer is poured out?
2) What is the best way to get the layer of beer off the yeast w/out losing any of the slurry? Is it okay if there is still a small layer of beer when pitching?
3) I saw the "flame" the top of the jar direction. What exactly does that mean? Is it simply taking one of those bigger Bic lighter things and heating up the jar?

Thanks!