Preparing A Yeast Starter Using Canned Wort

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In my previous article Wort Canning To Save Time, one commenter questioned where the time savings were. Well, ask and ye shall receive! In this article, I'll show you how I use pre-canned starter wort to make preparing a yeast starter an extremely quick process.
As I mentioned in the previous article, the problem with yeast starters is that they're time-constrained; you generally have to prepare them a set number of days prior to your brew day to ensure the maximum freshness and viability of the yeast. I usually brew on the weekend, which generally means I have to prepare my starter on Wednesday night. This is still true using the pre-canned method, but most of the work has already been done. Instead of boiling and chilling, I only need to pop a few lids open. It used to take me about 30 minutes to just make the wort. With pre-canned starter wort, making a starter only takes about 10 minutes from start to finish.
The required materials for this task are very minimal, and are shown below.

Caption: Materials for making a yeast starter from canned wort
You will need:
Some liquid yeast
A flask
A funnel
Something to cover the mouth of the flask (I use aluminum foil)
A stir plate and stir bar (optional)
A bottle opener
And of course, some pre-canned starter wort
I take my yeast out of the fridge and smack it as soon as I get home from work, then go about my Wednesday night as normal. By ten minutes before bed time, my yeast pack is nice and swollen and I set to work making my starter.

Buckets of PBW and StarSan
First, I fill a bucket with some hot PBW to throw my jars in after I've opened them. I also throw my stir bar, funnel, and a piece of aluminum foil into a bucket of StarSan.

Sanitizing the flask
Next, I pour a couple of quarts of StarSan into my 5L Erlenmeyer flask using my funnel, and give it a good shake to make sure all inner surfaces are good and sanitized. I usually use my 5L flask, as I rarely prepare a starter smaller than 2L, and my 2L flask would be too tight a fit for such an amount. In this example, I'm making a starter for a 5 gallon batch of Czech Pilsner, so I need a 5L starter.

Opening the jars of canned starter wort
After dumping the StarSan out of the flask and putting the funnel back in place, I open my jars of pre-canned starter wort one by one and add them to the flask. Another commenter on my previous article expressed concern about the lids popping off with simple handling. If you've canned them properly, this will not be a concern. My fingernails would come off before the lid would, if trying to open by hand. Fortunately, a bottle opener makes the perfect tool for prying the lids off of the canning jars.

Add the wort to the flask
Next, I pour the starter wort into the flask. Using a funnel helps minimize the mess, as I'm sure I don't have to tell you how sticky and messy wort can be. The jars will have some break material in them " I always try to get as much liquid as possible out of the jars, leaving the trub behind. In addition, the jars don't quite hold a full liter when allowing room for foam during canning. This is why you see 6 jars of starter wort in the first photo, for a 5L starter.

Time for the yeast to chow down
As I empty each jar, I throw the lid in the garbage (they're not reusable) and the empty jars into the bucket of PBW to soak overnight.
Next I sanitize the pouch of yeast, carefully tear it open, and pour it into the flask using the same funnel. I take the sanitized foil, folded it over onto itself, and cover the mouth of the flask. I then give it a good shake for a minute or so to really aerate it well.

Yeast, wort, flask, and stir bar on a stir plate
Finally, I drop in my sanitized stir bar and place the flask on my stir plate. I place a little square of that foam non-skid material on the stir plate to help keep the flask from slipping. This is simply that foam material you can buy at the hardware store, intended to line your kitchen drawers and prevent slipping.

A helpful reminder
One little trick I learned early on is to add some sort of reminder to the flask to help prevent you from dumping your stir bar into your carboy (at best) or down the drain (at worst). I slip a little reminder tag under the elastic band. It's obvious that the flask contains a stir bar while you see it sitting on a stir plate, but remember that you'll likely be cold-crashing the starter for a day or so before you actually pitch it, and when taking a flask out of the fridge, it's far less obvious that it contains a stir bar. You might think it's overkill- so did I, until I lost my first stir bar down the drain of my utility sink.

Success! Happy yeast, feasting and multiplying
Twelve hours later, my yeast is obviously happy, producing tons of CO2 and multiplying like crazy. After 48 hours on the stir plate, I move the whole thing into the fridge to cold-crash for a day. On brew day, I take it out to let it gently warm up while I brew, then I decant most of the spent starter wort, swirl up the yeast with the remaining bit, and pitch it into the main batch.
Preparing the yeast starter shown in the pictures took me about 20 minutes, but I was taking pictures throughout the entire process. Without that overhead, this process should take you no more than 10 minutes.
I hope you enjoyed this pair of articles on how I optimize my yeast starter process. Another comment I saw on the previous article suggested creating double-strength starter wort during the canning process (by using twice as much DME/LME), then diluting each jar with some sanitized water as you prepare the starter. This is a great suggestion, as it would allow your stash of canned starter wort to go twice as far, as you'd only need half as many jars to produce the same amount of 1.040 gravity starter wort.


Using canned wort for starters really is a huge timesaver (and economical, especially when canning extra wort from an all grain batch instead of using DME). I really like this article, as it is well written and focuses on best practices. If I am honest, I take some shortcuts that cut down on the time even further. Since I am building up starters from a slant, I just spritz the interior of my flask with star san, wait a minute, pop the top on a jar of canned wort, dump it directly into the flask (I have managed to avoid a funnel as jars pour rather well). Then I dump the contents of my prior starter into the flask, cap with tinfoil, and put it back on my stirplate. It takes all of about three minutes. Given that I step it up multiple times during the week, simplifying the process as much as possible is invaluable.
I don't have a canning setup and I am not particularly interested in getting one. But I have used second and third running frozen in a Mason Jar for started with great success. The last one cracked the jar on me as quart freezer jars are not really available.
I'm thinking about using a zip lock gallon freezer storage bag, putting wort in that, and then vacuum sealing the bag within another bag since I do have a low end vacuum sealer. If that works, then I can boil the bags for 15 minutes and put them on the shelf somewhere. I'll post on the forums if I ever pull that off.. but the idea of "insta-starter" is pretty nice. I had to microwave the frozen to boiling and then put it into ice to get back to room temperature and that did take a long time...
Great write up but I would add spraying Star San on the lid/rim of the wort jar prior to opening.
Forgive my ignorance, but a 5L starter for 5 gallons of beer seems like an awfully large amount. I've never used more than 1.8L for a 5 gallon batch.
The main reason this would not work (for me at least) is that the size of a starter is not static across brews. Some require a 1.2L starter, some only a 0.8L starter, etc. This would undoubtedly lead to waste every time, as there would unlikely be exactly enough wort in a given jar.
I still say it takes you longer with this method, because you are neglecting to account for the time spent canning in the first place. What does that take, an hour? More? For me to make a starter with DME takes about 15 minutes. You say your method (sans canning) takes 10 minutes. Seems like a push to me, except that I don't have to worry about the canning process. I know, "to each his own", but just commenting here.
But anyway, why so large of a starter?
If you are worried about the time in canning, don't be. It is not as if you have to stand over the pressure canned the entire time. The only time you really have to be around it is when it is on heat, which is A half hour at most. I do little things while the canner is doing it's job, mostly involving cleanup from brewday.
Here you go MagicMatt:
19 pint jars of canned wort = 60 minutes
19 starters = 5*19 = 95 minutes (I think 10 min is excessive)
Total time = 2 hr 35 min (8 min/starter)
19 starters conventional method = 15*19 = 285 minutes
Total time = 4 hr 45 min (15 min/starter)
My conventional starters always take way more time than 15 minutes though. It might be 15 active minutes but I still need to block out time to hang around and watch for boil over and also cool it quickly to get the it pitched or get the next step going in time. The conventional method requires that much more planning ahead and is less flexible than already having safe, sterile, room temp wort on hand.
I do not think you really need a canning set up. You are boiling the water and DME, it's sterile now....boil enough water to cover the jars in your brew kettle and use that to sterilize your jars, lids, and rings. Pull out the jars, lids, and rings...fill with wort, put on the lids and rings and pop them back in the boiling water for 20 minutes. Pull the jars and let them cool, listen for the POP, and you will know they sealed good.
NOW....I have never done that with wort before. But, I have done a few tons of hot sauce that way with no problems. Everything is sterile already so all you're really doing is sealing the jars...hot water bath style.
@Mismost - Do you some google searching on canning wort. Your method is frowned upon, it leaves open the possibility of botulism. Also, boiling temps don't sterilize, at least not that quickly.
Lager starters > ale starters
And there is absolutely time savings, if you can a bunch of wort at once. One batch of canned wort can make enough for many starters, so you're only making the wort once instead of each time. It wouldn't make sense to only can a few liters of wort at a time, unless you just wanted to spread out the time usage over separate days.
This is bad advice. You cannot safely can wort with water bath canning due to the risk of botulism. Wort is low acid and must be pressure canned.
Most of my batches are 15 gallons. Canning absolutely saves me time. Especially if your brewing a lot and have multiple yeast steps going. I generally can 20 quarts at a time, once or twice a year. Cooling 10L of wort is a PIA! I pull the last runnings from a batch. I will say I tried it w/o boiling it first. I didn't like the results. I now boil the wort while I boil my batch. It adds a little to the day, but I think it is worth it. I do 20 minutes at 15# in the canner.
Once again @kombat beautiful documentation of the process. Tremendous job on these two well written informative and well presented articles.
Thanks for putting them together.
Just another question for you canning folks regarding botulism - why is it a concern for wort boiled and then canned, and not for wort boiled and then fermented and bottled/kegged?
Finally, a brewer might ask, If boiling doesnt kill C. botulinum spores, why isnt botulism more common in homebrew? When beer is fermented, the pH drops " usually to 4.0"4.4 " below the threshold that inhibits growth of the bacteria. If C. botulinum spores are present, they cant grow and produce enough toxin in the time between the wort being cooled and fermentation finishing to cause a problem.
So, here is something I did leave out.. The other thing I didn't like about freezing my wort was the space quart jars took up in the freezer. If I did the bag in a bag and then sealed it I could still freeze the bags... I could "boil them" before freezing then put them into boiling water until they hit pitch temperature when using them later... I would imagine, even though I am not pressure canning, freezing them would inhibit the growth of botulism as well.. So for not wasting third runnings, I can still do what I've been doing but have it take up less space. Kinda of a bummer, I did forget about the botulism thing and thought, if I boiled the bags long enough I could get away with storing them at room temperature or keezer temperature.. I suppose I shouldn't... thanks...
So here is the deal with my idea. You need 240F to kill the botulism spores, so a mylar bag would be needed. That then put into a 250F oven for a half hour might work, but I suppose the reason you don't see this is that it's probably going to be more expensive than it is worth to do. interesting...
@thekraken Sorry I missed your earlier reply with the time breakdown scenarios.
The only thing I have a problem with is that you say 19 pint jars gives you 19 starters. That'd be less than 500mL starters. So realistically, you'd probably use 2.5 - 3 jars (1.2L - 1.4L....or more) per starter. The less starters you get out of a canning batch, the less of a return on your time you'll see.
Using the new numbers:
19 pint jars of canned wort = 60 minutes
19 / 2.5 = 7.6 (round up to 8)
8 starters = 5 * 8 = 40 minutes
Total time = 1 hr 40 min (12.5 min/starter)
8 starters conventional method = 15 * 8 = 120 minutes
Total time = 2 hr 0 min (15 min/starter)
So there's a 20 minute time savings, over 8 starters.
That's 150 seconds saved per starter.
All's I'm getting at is it's just another way to skin a cat. It may be more convenient on the back end, but requires more preparation on the front end. There's nothing truly eliminated here. In fact it may even be more cumbersome because now you have to have canning equipment and jars and storage space, etc. If you do already, then great. To each his own for sure. But unless you're cranking out enough wort per canning to yield 15-20 starters, you won't be saving any serious time as a result, only the perception of it.
With that said, I don't own any canning equipment (other than 4 or 5 mason jars) so I'm predispositioned to stick with my current methods. But if I ever have the opportunity to get my hands on canning equipment large enough to let me can a big ole batch of starter wort, I'll definitely do it!
Can on!
Nice article. Clear, concise, good pics.
Instead of that note that there's a stir bar in there, just get a big rare earth magnet and when you remove the starter from the stir plate, use magnet #2 to grab the inside stirbar. Pull it to the side. No chance of dumping the stir bar into your fermentor.
MagicMatt: As I tried to make clear in both articles, the time saving comes on the night you prepare the starter. 5-10 minutes vs. 30-60. No heating/cooling cycle has to occur. Yes, it takes more time in total, but you can commit that extra time whenever it's convenient, instead of having to find that time precisely 3 days prior to brewing.
There are lots of examples of "time saving" tactics that actually end up taking more time overall. "No-chill" brewing, for example. It turns a 5 hour brew day into a 2-day task, but reduces the active time commitment required on the actual brew day. Overnight mashing, for another example. It "saves time" on the brew day, because you wake up and you're already ready to start collecting first runnings, instead of waiting to heat strike water and doing a 60-minute mash. But in actuality, you've dragged the process out over 2 days again.
So given those well-established and accepted examples, I think it's perfectly fair to continue to portray canning starter wort as a "time saving" tactic.
I like this method. Yes, it takes time to can. it takes time to prepare the wort to can as well. When I do it, I'm generally doing a batch of beer and make extra, or I simply plan a really quick batch of wort using BIAB on the stovetop.
The winning idea here is to save the time when it's most precious. An odd weeknight when you have time is ideal to can it up. Having the ability to make a starter in less than 10 minutes on a busy weeknight is fantastic.
I can do it while making dinner and then wash the 1-2 jars with the dishes or toss in the washer.
I avoid liquid yeasts now because I'm currently out of canned wort and it just seems like a hassle to make a starter the usual way now that I've used canned wort. Luckily I mostly make pale ales and beers that are fine with dry yeast.
Id rather just make it all when i need it. just put water, dme and fermcaps into the flask and boil. cover and leave it alone. come back hours later and pitch the yeast and put on stir plate. i dont need to break out the starsan at all. the boil sanitizes everything for me.
@MagicMatt - I should have mentioned in my first reply that my pint jars are ~1.085 og (I did mention this in the comments of kombat's previous article). So just pour 1 jar into a flask, top off to 1 liter with bottled water, you got your self a 1 liter starter. So it is still 19 starters for my case. You can make them as concentrated as you want to best suit your needs. When the need for a starter does arise it shouldn't take longer to put together than a glass of chocolate milk.
I still believe there are/can be significant time savings here, but the convenience factor is a real draw for me.
I see the cash investment as the biggest problem with this. Like you said, if you don't already have the equipment, or plan on using it for other things, it just may not be worth it.
Or you could just go to Northernbrewer.com and order a 4 pack of Fast Pitch Canned Wort and you can save even MORE time...
I'd rather spend the $10 for already made canned wort and not have to deal with the hassle of trying to sterilize everything and also having to deal with DME.
One can of wort, one can of water and pitch your yeast and you're done. Seems worth it to me...
@bacgabe I too build my starter from a slant. I've been toying with canning wort because it has sometimes been a pain to try and make a couple mid-week as I'm stepping up. My hang up so far has been with the size starters I make (due to smaller batch sizes, I usually do 2-3 gallons at a time) and if I were to can a quart I may only use part of it. If I use the rest in the next day or two would it keep okay in the fridge? I fell like it would, but haven't solicited opinions of those more experienced than myself. What say you?
OK, you have caught my interest! After thinking about this over the last couple of brew days I think I've come up with another time saver to add to your time saver! Here is what I did today. I was brewing an IPA that ends up being a 1.053 O.G. I have been thinking that this wort is close enough to the right S.G. to use as a starter wort, so I increased my preboil volume so that I could save a couple of quarts to use in another starter the next time I brew this recipe! After the boil was finished and I was draining through my CFC I just filled 2 sanitized quart mason jars with wort and placed it in the fridge. Next time I get ready to brew this recipe I can pitch the wort and my yeast into the flask, put it on the stir plate in what... like 2 minutes?! LOL... too easy ( ;
Great write up!
I have used this method for over a year. I cann in a pressure cooker using the final runnings from my mash on brew day. Usually I can get 2-4 quarts in the 1.020 to 1.030 range. Beats just dumping it. Then I simply put in pressure cooker and let her rip while the BK is coming up to boil. Since I biuld starters from slants, I try and cann some wort in pint jars for initial growth and save the quart size for stepping up later.
@danthebugman, I have occasionally only used part of a quart size initially and saved the rest in the fridge for a day or 2 for the step up. Your nose will tell you if there is a problem.
Works like a charm.
I've been canning my wort for starters for years. Since they are pressure cooked they will store on the shelves for a really long time. When I started I didn't even have to buy anything (except lids) because we can garden veggies throughout the summer. I can in quart jars. I have a couple 1 liter flasks, but when I make a 2 quart starter I'll use a 1 gallon jug. As for the stir bar, I use a rare earth magnet to locate the stir bar and then drag it to the mouth of the jug to remove it.
Just tagging an extension here... I have been pre-preparing starter wort for years and if someone brews frequently, I can't imagine why anyone wouldn't. Similarly, I use a 5L flask - I place 4 cups DME in flask, add water to total of 4.5L - my experience has provided that this creates a 1.035 starter wort - and this quantity is perfect to create 5 liters (I use 1qt mason jars - and I *do* keep/reuse the lids - just clean each time).
THE BEST PART: The jars are kept in refrigerator. Yeast is kept in refrigerator. You're "supposed" to let yeast warm to room temp before using - BUT if both are kept in the same refrigerator, why can't they be mixed *cold* and brought to room temp on a stir plate together? EZPZ, lemon squeezy.
Even better - this process has followed me right not opening a brewery and allows me to save $$$$$ by creating my own stepped-up starters. Instead of using "pitchable" packs from the major yeast providers (costing well over $100 per) - I create fully pitchable quantities for 3BBL batches with only a single can (I am successfully using Imperial canned yeast). Having the mason jars handy just makes the process routine.