Burning in the bottom?

[ToddStark]

So, three extract brews boiled so far. Each time after pouring into the fermenter bucket I noticed a ring of discoloration that matched my stove burner on the bottom. Can see small marks in the discoloration from where my stirring spoon scratched the bottom. So something is lightly sticking to the bottom just where the burner is making contact and since it is such a large pot it is only maybe 1/3 or 1/4 of the bottom surface area.

Now my process is to bring my water to a boil then add the extract slowly with non stop stirring. Once combined, keep stirring often until I can get back to a fast boil then maybe I only stir a few times every 10-15 min.

-First attempt, I turned off the burner then added the extract. This is first time I noticed the discoloration and felt it must of burnt because even though the burner was turned off it was still to hot.

-Second attempt, I pulled the pot off the burner after boil achieved and slowly stirred in extract while stirring now stop until nothing on the ladle and it looked thoroughly blended. Again, noticed what looked like a burner shaped burn mark on bottom of pot when adding to bucket.

-3rd attempt, I pulled completely off of the stove after achieving boil and set pot of water on a wooden cutting board while I stirred in extract but yet again at the end I appear to have a burnt mark on bottom of pot matching the burner size and placement.

Questions:
Is this normal?
Should I be worried about off flavors due to burning extract?
Am I not stirring long enough or should I be letting pot and water cool down for long period of time before adding extract?
is it that I am not stirring enough once the pot comes back to a hard boil?

Thoughts/Ideas?

 

[flars]

Do you stir around the side of the kettle? This will create a whirlpool and draw extract to the center. Just like whirlpooling to pile hop debris in the center of the kettle before racking.

Are you keeping the heat on high to maintain an overly vigorous boil? Problem might be just applying to much heat.

Thin kettles will be more prone to scorching at the heat source. Thicker metals will transfer heat more evenly over the bottom of the kettle.

 

[Vandulus]

I had the same issue and it's sometimes due to the material the bottom of the kettle is made from. I had this problem with my Bayou Classic kettle no matter how much I stirred. Using a aluminum diffuser plate ($40-50 on Amazon) helped, but didn't eliminate the problem. I finally bought a new kettle (SS Brewtech) with a tri-clad bottom which has solved my scorch marks. Tri-clad kettles have a layer of aluminum sandwiched between two other layers, usually stainless steel.

 

[ToddStark]

Do you stir around the side of the kettle? This will create a whirlpool and draw extract to the center. Just like whirlpooling to pile hop debris in the center of the kettle before racking.

Are you keeping the heat on high to maintain an overly vigorous boil? Problem might be just applying to much heat.

Thin kettles will be more prone to scorching at the heat source. Thicker metals will transfer heat more evenly over the bottom of the kettle.

Yes, I probably do tend to stir in circle around edge of pot most of the time and yes I do keep burner on high all the time.

Thank you, I will keep this in mind and modify things to see if they help out, if not then maybe I will need to look at better quality equipment.

Thank you all for your input. I was starting to get a bit frustrated with this little problem.

 

[IslandLizard]

Make sure to "scrape" that center area with your spoon while stirring. I use a long plastic spoon and one side has definitely developed a flat edge over the years. Stir a bit more often may help to prevent it sticking too much.

It's generally better not to add all the extract at the beginning of the boil. Add only 1/3 to 1/2 of the total and the balance right after the boil is done and the flame is off. The lower sugar concentration helps in reducing caramelization and possible scorching, as well as providing you with a better/fresher tasting wort/beer.

For partial boils (top off with water after the boil) this method even more desired. As long as the wort remains above 165°F for 15 minutes it will pasteurize the DME/LME.

 

[ncbrewer]

I understand your concern about the scorch marks and agree with taking reasonable steps to optimize. But it seems to me that if you don't get any burnt smell or taste, you don't really have a problem.

My kettle is thin. The steps I take to prevent scorching are 1) Take the kettle off the heat for 1 minute before adding extract 2) Add only 1/3 of the extract at the beginning and the rest at flameout 3) Stir while adding, and 4) Stir for an additional 2 minutes after it all seems to be dissolved.

 

[GHBWNY]

So, three extract brews boiled so far. Each time after pouring into the fermenter bucket I noticed a ring of discoloration that matched my stove burner on the bottom. Can see small marks in the discoloration from where my stirring spoon scratched the bottom. So something is lightly sticking to the bottom just where the burner is making contact and since it is such a large pot it is only maybe 1/3 or 1/4 of the bottom surface area.

Now my process is to bring my water to a boil then add the extract slowly with non stop stirring. Once combined, keep stirring often until I can get back to a fast boil then maybe I only stir a few times every 10-15 min.

-First attempt, I turned off the burner then added the extract. This is first time I noticed the discoloration and felt it must of burnt because even though the burner was turned off it was still to hot.

-Second attempt, I pulled the pot off the burner after boil achieved and slowly stirred in extract while stirring now stop until nothing on the ladle and it looked thoroughly blended. Again, noticed what looked like a burner shaped burn mark on bottom of pot when adding to bucket.

-3rd attempt, I pulled completely off of the stove after achieving boil and set pot of water on a wooden cutting board while I stirred in extract but yet again at the end I appear to have a burnt mark on bottom of pot matching the burner size and placement.

Questions:
Is this normal?
Should I be worried about off flavors due to burning extract?
Am I not stirring long enough or should I be letting pot and water cool down for long period of time before adding extract?
is it that I am not stirring enough once the pot comes back to a hard boil?

Thoughts/Ideas?

Are you using LME or DME?

Added at the same rate, DME, being a powder, will dissolve faster and suspend easier than LME. LME, being a heavy syrup, will head straight to the bottom of your pot and if you don't add it really, REALLY slowly and stir vigorously during adding, it will settle and scorch.

Is your burner electric or gas?

Turning off the heat under an electric element has virtually the same effect as leaving it on another couple of minutes. While turning off a gas burner should almost instantly alleviate the possibility of scorching, it's not entirely foolproof. In either case, constant stirring is the only way to insure the least amount of scorching. Even with a lot of stirring, I have gotten the same scorch marks you have at the bottom of my pot when using extract. Is it possible to totally eliminate the possibility of scorching when using extract? Don't know for sure.

 

[ToddStark]

Questions first: My instructions have me adding all my liquid extract soon as I get my water to a boil and then boiling it all together for an hour. Are you guys saying it is not only acceptable but preferable to only put part of the liquid extract into the boiling water and then boiling it for an hour adding my hops an so forth and then when the boil is done, add the remaining extract?

Answers: I have an electric stove top. Pot barely fits on it and is because of this I have the burner set to high just trying to get and keep things boiling. My extracts have all been bagged liquid. It is a very very thick liquid that can take 5-10 min for me to slowly pour in and stir.

as far as any off flavors, I have brewed all three batches before my first is even ready to drink. So I honestly don't even know if any off flavors have been added due to this issue. Now I have quick tasted each batch before they went into the fermentors and I didn't detect anything from the small tastes I took

 

[Scarecrow57]

The problem you are having is due to an inexpensive boiling pot. A single layer, thin, stainless steel pot will not dissipate the heat well. As mentioned above, if this is a concern get a triple bottom pot. A good pot will cost $150 or more....

You can try taking the pot off the burner, adding the extract, starting a good stir (with whirlpool) and putting it back on the heat. A continuous vigorous stir will keep things form settling. Once you return to a hard roiling boil it will self stir.

 

[ChemErik]

$150 should get you a good 15 gallon pot with a valve if you shop around. If the OP wants a 5 gallon pot for partial boil extract batches, good triclad 5 gallon pots can be found under $60. My triclad pot was $40 at the local outlet mall and my local HBS has a triclad polar ware 10 gallon for $99 I'm considering.

 

[GHBWNY]

Questions first: My instructions have me adding all my liquid extract soon as I get my water to a boil and then boiling it all together for an hour. Are you guys saying it is not only acceptable but preferable to only put part of the liquid extract into the boiling water and then boiling it for an hour adding my hops an so forth and then when the boil is done, add the remaining extract?

Answers: I have an electric stove top. Pot barely fits on it and is because of this I have the burner set to high just trying to get and keep things boiling. My extracts have all been bagged liquid. It is a very very thick liquid that can take 5-10 min for me to slowly pour in and stir.

as far as any off flavors, I have brewed all three batches before my first is even ready to drink. So I honestly don't even know if any off flavors have been added due to this issue. Now I have quick tasted each batch before they went into the fermentors and I didn't detect anything from the small tastes I took

Extract is basically concentrated wort that has already been boiled in the process, so it's not necessary to re-boil it for an hour except to sterilize it (which 15 min will do) and integrating it with the hops, which have to be boiled anyway to extract the oils. I think kit instructions tend to over-simplify for the novice, thus boiling everything together for the same length of time is the easiest.

You won't get any significant off-flavors from a little scorching. Off-flavors are usually a result of a yeast/fermentation issue. If you're brewing a stout or porter, you're not likely to taste any scorching at all.

 

[ncbrewer]

Questions first: My instructions have me adding all my liquid extract soon as I get my water to a boil and then boiling it all together for an hour. Are you guys saying it is not only acceptable but preferable to only put part of the liquid extract into the boiling water and then boiling it for an hour adding my hops an so forth and then when the boil is done, add the remaining extract?

One thing that complicates the issue of late extract addition is that the boil will be at lower gravity than the kit instructions called for. According to the traditional info, hop utilization is higher (more IBU's) when boil gravity is lower, so you would need to adjust the hop additions if you want the same bitterness. But in recent years there has been disagreement about this theory, and as far as I can tell it still hasn't been resolved. You could split the difference when adding hops and then adjust your next brew based on how you liked it.

 

[enokidaki]

I don't know why y'all use spoons and plastic utensils for stiring. I had a long steel grill spatula that I scratch the bottom of the pot with every few minutes during the boil, piece o cake!

 

[ToddStark]

This original post is a year old now and just wanted to let people know that I continued to have this issue of scorching on the bottom of my brew kettle up until the point that I bought a nice heavy duty kettle from Spike Brewing. I have 4 brews with this new pot and never any scorching.