OKtoberfest help

I've been brewing for about 6 months and made an Oktoberfest (with German ale yeast) that may have gone wrong. I used the Brewing Classic Styles recipie and looking back it looks strange. The all grain doesn't look like the extract recipie. After 2 weeks in the bottle, I tasked and I find a cardboard like aftertaste that is really anoying. Here is the recipie.

10gollon batch

8.75 Pilsner
6.75 Munich I
4.75 Vienna
1.25 Caramunich I

.75 Hallertau @60
.75 Northern Brewer @60
1 Hallertau @ 20

SIngle infusion @ 151 (Oddly enough my strike did hit 160, but I I added cold water to get it to 151, this was my first 10 gallon batch in my set up)

I fermented at 61-64F in an ice bath over a week then transfered to secondary for 2 weeks, then botted for 2 weeks.

Normally I would wait to taste, but looking back at the book, the Extract version 4.4 pils LME 4.4 Munich LME and 1.0 Caramunich steeped has no vienna. This seems odd as does such a small portion of base malt in the all grain.

The recipe looks fine to me. A cardboard taste is usually associated with mishandling of the product at some point after fermentation, such as the introduction of oxygen at bottling. You may also be tasting the combination of Pilsner and Munich malt. And lastly, sparging to much or to hot will lead to tannin extraction that could cause a paper/cardboard mouthfeel and flavor. I would try and let the beer age a while longer before passing final judgement on it. A few weeks cold conditioning would also benefit the beer.

I am hoping it is that it needs more age. I've used the same process through about 18 batches now and no issues. Just thought the Vienna malt may have been the issue. It also could have been that I sampled the last one I bottled. I always wondered if that one for each batch will taste different as their are air bubbles and certainly more oxygen.

Thanks for the help. I am always trying to learn more with each batch.

That recipe looks a lot like the munich madness recipe I just made 5 pilsner 4 munich 3 vienna 12 oz crystal 60 for 5 gallons. If that last bottle you poured got lots of air in the line thats probably all it is i agree cardboard is oxidized

There can be multiple problems causing the cardboard like taste you're getting. Over Oxidation can be one of them, but I think it might be in the fermentation techniques. Using an ice bath for fermentation is just too 'sketchy' and very hard to keep a constant temperature like that. My main suggestion would definitely be work on a way to get your fermentation temperature deadly accurate and constant. My buddies and I have built a chest freezer with a temperature control that turns on and off from a 1 degree difference that what we have it set at. This set up was relatively cheap for the benefits as well. I can definitely understand if you have space issues though, which might be the reason behind cold baths for your beer. Although I would rather have a more constant temperature around 69 or 70 F, than it varying much in the bath around 61-64. /2cents

I usually ferment on the basement floor and I'd say the ice bath keeps as good of a temperature as just leaving it on the floor. On the floor, it will vary over the week from 67-69. It is not really an ice bath. It is a bin with 5 gallons and I swap 1/2 gallon of ice every 12 hours. I did just get a fridge but need to get a digital thermometer. By the way, I used the same technique ice bath on a Dunkelweizen that came out awesome. Thanks for the tip on the thermometer. I really need to do this.

Also, I've had a bottle in the fridge for 2 days and will wait a few more and sample again.