If there is one thing brewing beer requires that I don’t have it would have to be patience… really, I hate waiting 2 or three weeks for things to happen, but fortunately it has been worth it all along. There are two stages that require that patience, fermentation and conditioning.

I think fermentation is the most screwed up step most newbies make because all the emphasis is on the boil and not so much fermentation. Most brewers feel like their job is done as soon as they pitch their yeast and place the airlock in their fermenter.

That being said… here’s a question I got from a reader…


My kids bought me a Cooper’s kit on my birthday, and it came with a lager recipe. I’m glad I found your site since the kit’s instructions are not easy to follow.

The beer has been in the fermenter for a week now, but I’m not sure if I messed something up. I was getting ready to bottle, so I opened up the fermenter and took a gravity reading which read just a little above 1.010, so I figured I’d let it sit for another day or two. It didn’t look bad, but when I tasted I felt it was a little cidery. I think it tasted better before it went into the fermenter?

The kit came with 1 kg of sugar, which I have yet to add and I’m wondering if that will get rid of the cidery taste?

Will letting it sit longer help it?

I fermented the beer at 74 F in an extra bedroom, if that means anything?

Steve M
Waterbury, CT


You are illustrating the reason why short fermentation times are a bad thing. I don’t blame you though, I bottled my first batch sooner than I was supposed.

It happens… we just want to drink the darn thing and not have to wait!

Now here’s the thing… if you fermented at 74 F, that’s your first problem. I’m assuming the recipe is using a lager style ale yeast and not a true lager yeast. See, lager yeast needs to be fermented closer to 50 F so I’m assuming the kit came with a lager style ale yeast.

The difference?

What separates ale yeast from lager yeast is 1) fermentation temperatures 2) lager yeasts ferment a sugar (raffinose) which ale yeast doesn’t ferment. A common rule of thumb to identify the two types of yeast is that ale yeast are top fermenting while lager yeast are bottom fermenting. There are however, some lager yeast that like to ferment at warmer temperatures (60-70 F) which is the type of yeast used in steam beer… It’s actually now being called California common beer thanks to our fellow brewers over at Anchor Steam brewery in CA.

Ok, now that I got that off my chest, on to fermenting times.

When beer is fermenting, it produces acetaldehyde, which is the source of the cidery taste you swigged. This is common in young beers with high alcohol content or in your case, trying to rack too soon. Basically, the yeast is not done fermenting so you should leave your beer in the fermenter longer. I normally go for 10-14 days even though my lack of patience kills me when I do so, but you don’t really have a choice if you want good beer.

There is a possibility that a cidery taste is due to an infection, in which case you can’t do much about it. Normally this happens if there are fruit flies around and they seem to be very attracted to our brew so keep your fermenter closed and watch out for those basterds… in your case it sounds like it’s just young beer and time will fix it, otherwise you’ll have to dump the infected beer.

Breaks my heart…

    7 replies to "Why Short Fermentation Times Are A Bad Thing"

    • Mighty Mike's Ale

      I can relate. When I started brewing, waiting was and still is the hardest part about making beer. To encourage you just remember the old attag’e “All good things come to those who WAIT!”

    • Tommy

      Jorge, Thanks for all the good info on our favorite hobby. I brewed my first 5 gallon mini mash of Honey blonde yesterday. After allowing the california v ale yeast to warm from my refrigerator for 6 hrs, I pitched it into the wort at 77 degrees. Now it is fermenting at a temp of 68 degrees. It is bubbeling rapidly now, but Im wondering if this drop in temp will affect the taste and also what the ideal temp for this type of yeast is ?

    • Jorge


      When it comes to taste coming from yeast the answers are rarely ever clear… I’ll start out with this…

      Normally you want to pitch your yeast at the temperature your beer will be fermenting… the wort should also be as close as possible to that temperature…

      If your yeast is warmer than your wort, you may shock some yeast with the temperature shift and they may go dormant… in which case, your problem will be mostly with attenuation. Then again attenuation does affect taste…

      However, all this changes depending on the temperature range we are talking about. In your case a 10 °F difference may not be as noticeable as if you were fermenting at 60 °F where most ale yeast strains tend to go dormant…

      In your case, I wouldn’t worry much about taste… I wouldn’t even sweat attenuation, but if you are really concerned take a gravity reading 7 days from the day you pitched your yeast and make sure you’ve reached full attenuation… I think you’ll be fine… I usually do the same (leave the yeast warm up at room temperature and pitch to a cooled wort) and haven’t had any issues…

      California Ale V yeast strain (WLP051) ferments best at 66-70 °F…

    • Shaun

      I made the same beer coopers yeast is ale yeast recommended for higher temps. Tends to be a bit cidery for a while if im honest. Mine took 2 months in the bottle to age. it also actually took 2 weeks to ferm. It was so slow i got bored and added Fermentis S04. Which got the job done 🙂

      • Jorge

        Are you brewing with a kit?

    • john gibbons

      A similar thing happened to me with my first brew (coopers lager). I pitched the yeast at about 24C and then that night the temperature went down to 16C. In the morning I saw this and quickly put the vessel in a tub of water at 26C to get the temp up and kept it around the correct temperature range for the rest of the brew. After about 10 days at 24C the wort had only attenuated down to 1011, I tested it again over the next two days and eventually bottled it on day 13. I then placed the bottles in a plastic tub for 2 weeks 24C. After the 2 weeks I cracked open a bottle and it had hardly carbonated at all. After the third week in the bottle it finally had a decent head on it and the overall taste of the lager was weak and slightly cidery.

      Since then I have always managed to keep my brews at the right temp from the beginning and they haven’t turned out that bad ever since. Even the Extra Strong Vintage Ale that I bottled too early (FG 1015) ended up tasting ok after about 6 months in the bottle. Before that it was the foulest thing I’d ever tasted, and exploded out of the bottle when I opened it during the first 3 months (overprimed by bottling before end of attenuation).

      • Jorge

        We learn more from experience, but it’s well worth it in the end… cheers!

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