Should any preservatives in canned pumpkin bother yeast?

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I am planning to brew a pumpkin ale later today (my first one), and in
preparation I have gone over all the pumpkin recipes on the Cat's Meow
as well as those on  I have also read every post that I
can find in an assortment of brewing forums.  Some say to add the
pumpkin during the boil, while others say to add it to the mash; the
mash seems more logical to me in order to achieve conversion of starches
(I presume pumpkin has some), so that's what I'm planning to do.  Some
also say to use only fresh pumpkins, while others say it is okay to used
canned pumpkin -- even in the mash -- and some even say that canned
pumpkin pie filling is okay; others caution not to use the canned stuff
in the mash because of the mess and possible stuck runoffs/sparges.  I
have a monster bazooka (10 feet long) and have never had a stuck runoff
yet, including when I've used high quantities of oatmeal and even a
wheat beer made with regular flour, so I'm willing to take my chances.

My question pertains to preservatives.  I'm going to the store in the
morning to buy the pumpkin, so I'm not sure whether I can find any cans
that don't have preservatives; however, assuming the cans do contain
something, is it reasonable to expect that the mashing and subsequent 90
minute boil will remove them or dilute them enough that they won't hurt
the yeast?  I'm planning to mash about 5 pounds of canned pumpkin in 10
pounds of grist to make a 5 gallon batch.  There were some comments
somewhere during the course of my research that suggested that
preservatives are not a problem, but I'd like to confirm that if
possible before buying it.  For instance, if anyone were to definitively
report that they used canned pumpkin containing preservatives and just
couldn't get the yeast to ferment, and there are no contrary experiences
by brewers who definitely used preservatives without problems, then I'd
feel compelled to switch over to fresh pumpkin.  The only reason I'm
avoiding fresh is that it just seems to entail a lot of extra work that
I'd like to avoid if possible.

Any help will be appreciated.  Thanks.

Bill Velek

Re: Should any preservatives in canned pumpkin bother yeast?

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Bill; I started out making the regular interpetation of a pumpkin ale
which I made for about 5 years (you know the one, middle of the road
English pale ale with pumpkin + spices). I first tried fresh pie
pumpkins, and one year tried canned. All were pretty good but
somewhere along the line I got the idea to change the base beer to a
porter and things got magical from there. Also, I started moving the
volume of pumpkin in the mash *way* up and switched back to fresh pie
pumpkins. It's not a lot of extra work and I like the whole "fall"
feeling of it; it's sort of become an event around my house with lots
of people showing up to help out. If you use canned pumpkin, at least
be sure and bake it to get a little carmelization which will add a lot
of flavor.

You have probably already bought all your ingredients, but I'll post
my pumpkin porter recipe in the latest incarnation here. The spice
mixture I use came from Cook's magazine "Perfect Pumpkin Pie."

5 gallons:

16 pounds of fresh sweet pie pumpkins, cut up, seeded and roasted
until very soft and browned (roast cut-side up). Scrape the pumpkin
out of the shell, mush it up and add it to the mash tun with the
strike water.

10 lbs Marris Otter
2 lbs munich
1 lbs special B
1 lbs chocolate malt
1 lbs 20 lovibond crystal

Single infusion mash - 90 mins - @ 154.

1.5 oz northern brewer pellets @ 60
1.5 oz northern brewer pellets @ 20

Added spices with 3 minutes left of a 90 minute boil:
1tbs + 2tsp cinnamon
1tbs + 1tsp fresh ground nutmeg
1tsp ground ginger
1tsp ground mace
1tsp ground allspice
.5 tsp ground cloves

Yeast: white labs WLP051

Sparge takes a long time, I suppose it would go faster if I added some
rice hulls but it's never actually stuck on me yet so I've kept them


Re: Should any preservatives in canned pumpkin bother yeast?

Bill, if you picked up your ingredients last weekend than you probably
already know that most canned pumpkin (not pumpkin pie mix) does NOT
contain preservatives. I know Libby' doesn't, neither do the store
brands I've bought.

Into the secondary I usually add a couple of handfulls of sanitized
oak chips which I've soaked for a few days in bourbon. The bourbon/oak/
pumpkin combo is great.


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