Watermelon Wheat

I’m doin a watermelon wheat soon and I am gonna put watermelon puree into the batch. I have seen two different recommendations.

  1. Put it in the secondary (no other directions given)
  2. Put it in at the end of the boil and keep the temp above 170 for 15 minutes to remove any possible infections that could exist in the watermelon.

So…if I did #1 do I run a high risk of infecting my batch if I do nothing other than pitching it into the secondary after puree’in it?

Please let me know what you think?


If you follow recommendation #1 you are going to rely on the alcohol content of your beer after primary fermentation to keep any nasties in or on the watermelon (which there will be) from spoiling your beer. This is a common practice when adding fruit to a secondary fermenter and works rather well. This would be the route I would suggest.

#2 relies on the heat from your brew kettle to sanitize your melons. I do not particularly think this is a good route. One reason, your going to lose a lot of the flavor and aroma of the watermelon (which is incredibly hard to get to come through in a beer in any case) if you add it before primary fermentation, especially to water that hot. On top of that, just because the temp is over 170 does not guarantee that you’ve killed the nasties in/on the melon in the first place. In effect you’re losing any real chance of watermelon flavor or aroma while possible introducing infection to your beer. IMHO this would be a bad idea.

You’re only other real option is using watermelon flavor extract. I don’t know that I’ve ever seen it but I bet you can get it somewhere. This product it already sterile and it added to the bucket at bottling or to the keg at kegging. While not giving you the option of using real fresh fruit, it does give you the ability to directly control how much flavor is added with the security of knowing you’re not going to ruin your beer. In my estimation, this is your second best option.

#1 - Add to secondary
#2 - Use Extract
#3 - Add to boil @ 0 min

You could also freeze the puree and thaw it out the next day.

Bacteria and viruses are generally only made dormant by freezing temperatures instead of killed. 1
They would likely be mostly materially unaffected by this I’m afraid.

Thanks Trimack. Most of the directions I saw recommend putting it in after the primary fermentation…that is what I will try.

I have seen watermelon extract but I want to try using the real thing…it will be my first time ever adding any real fruit to the process and I am curious how it turns out…I don’t want to infect or spoil a batch of beer but if it happens then I will know better for next time.

Thanks again for the advice.


I made one this spring, and went through the same thing you are. I made a 5 gallon batch. I cubed up one an a quarter watermelon from the store. I froze it, and thawed it. I added it to PRIMARY after fermentation was done. I continued to let the watermelon ferment until I figured it was done ~1 week. I then scooped out all the watermelon and racked to secondary to clear. Beer came out good. I get a lot of good feedback. I would personally use less watermelon to make the flavor more subtle. Also, let it sit longer so you know any bits of sugar from the watermelon have completely fermented out. Had a few bombs after it sat for like 3 months. The pink yeast is pretty cool too

Keep in mind that people have been making beer for a very long time. Way way way way way before starsan was around.

Thanks ACKbrew…looking forward to making this beer next month!