making a yeast starter

the setup

To prep for my upcoming brew day on saturday (check back monday for results) I decided to make a yeast starter.

  • to be honest, I had never made a yeast starter before, and had relied on wyeast smack packs as a sort of “mini-starter” for my batches.
  • however, I have been running into some bad luck with recent smack packs that didn’t fully inflate, and one which didn’t take off at all.  this made for a headache on brew day.
  • in addition, as long as I have been brewing, starters have been getting pumped to me as a good idea for a fast and vigorous fermentation.
  • I am also interested in reconstituting bottle yeast in the future, and there’s no way I can do this without a starter, so I had to start sometime.
  • the kicker was that my shipped brew ingredients had been sitting out in the hot sun all day yesterday, and despite being wrapped with a cold pack, my smack pack was already swollen when I got to it.  I could either let the swollen smack pack sit in the fridge for a couple days and potentially run out of nutrients or make a starter.

I recently purchased a few items for the yeast starter process.

  • a 1000 mL erlenmeyer flask – realistically, you can use any type of container, but you can toss this flask right on the stove top and dump it into an ice bath without any problems.
  • some yeast nutrient – I got this mostly for reconstituting yeast so they would have a proper diet.  my smack pack already had nutrient in it, so I didn’t add any to this batch.
  • you will also definitely want some foam reducer, dry or liquid malt extract, and some aluminum foil.  I had all of this lying around from previous batches.
  • however, you can realistically make a starter with just water and some leftover DME or LME and any container.  the stuff above just eliminates steps from the process and/or makes the process easier.

for those interested, here’s a quick breakdown of the process I followed, based on various online tutorials:

weighing DME

  • I added DME and water to the flask in a ratio of 2 oz. DME/400mL water.  note here – if using a flask, add the DME first.  I waited until the water was boiling to add the DME – big mistake.  that stuff is like crazy glue once it gets warm and went everywhere but through the neck of the flask.

boiling wort

  • ADD FOAM REDUCER to your flask before the boil, or you will get a gnarly boil over, or if using a flask, a wort eruption.  In my opinion, this is the most important note of the whole process.  My 600 mL starter became a 400 mL starter in about a second before I realized I forgot to add the foam reducer.

i use star san

  • I whipped up a quick batch of sanitizer while I was waiting for the boil to complete.  you can never be too anal/safe!

ice bath

  • after boiling for a little over 10 minutes, I placed the flask in an ice bath, and cooled it to about 70F.

denny's fav

  • I then shook my smack pack and added the yeast.  I am using wyeast 2450PC – Denny’s Favorite 50.  Denny Conn is one of my favorite brew forum contributors, and I have used his recipes and followed his advice multiple times.  why not give his yeast a shot?


  • after adding the yeast, I topped the flask off with some sanitized foil and shook it up.  some people use stir plates or oxygenate their starter, and some use an airlock or foam stopper.  I was going to use an airlock, but the stopper I got was too small for the flask.  william’s brewing recommends a #7 stopper for their 1000 mL flask, but you need more like a #9.5 from what I read.
  • every once in a while (5-6 hrs or so) you will want to swirl the starter around to keep the yeast working.
  • another note – I have heard of people making multiple batches of wort like this and canning them using a pressure cooker.  They then have sterile wort ready every time they want to make a starter!  I might have to look into that.

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4 Responses to “making a yeast starter”

  1. Not a Dork Says:

    Hey, you might not want to add your de-foaming agent to your yeast starter. It contains sodium metabisulphite. The same stuff added to wine in order to kill the yeast.

  2. admin Says:

    whoa, you’re right about the sodium metabisulfite in the foam control. it seems kinda weird that they would put that in a product meant to be used primarily during fermentation. hopefully the amount is negligible since it’s used as a preservative, but I’ll contact the supplier when I get a chance to see what’s up. I have had friends use it successfully in starters, however, so I’m crossing my fingers, but I may reconsider using it in the future or look for an alternative. thanks for the advice! comments moved from “pyramid ale house at OAK” to here.

  3. - your homebrewing and beer destination Says:

    […] had saved the yeast cake from a biere de noel he had made about a week ago, and had made a starter with it the day before.  the starter was over 1000 mL and was showing heavy activity by the time I […]

  4. - your homebrewing and beer destination Says:

    […] my lesson from my last starter preparation, I added a little less than 4oz of DME and a pinch of yeast nutrient before adding any water to my […]

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