How to add DME

[Vintage Iron]

I'm relatively new to brewing (About 6 batches in) and have a relatively simplistic question.

I just figured out the concept of adding DME to the cooled wort to bring FG up if it is low. My question, is WHEN does one add DME? My normal brew day has me dumping cooled wort into the bigmouth fermenter, then adding water.

I've read about some brewers adding DME at the end of the boil. How would you know where your FG is (and how much DME to add) if you're going to add water to the fermenter to bring the batch up to the 5 gal mark after the fact? I've also read of some adding DME (boiled in a bit of water) to the cooled wort in the fermenter, which makes more sense, but still how does one calculate the add amount?

I guess I'm basically lost on this, so any guidance you can lend is greatly appreciated!

 

[RPh_Guy]

So, you're brewing all grain?

Take a pre-boil gravity. (Chill the sample. Adjust for temperature.)
If it's too low, add DME toward the end of the boil. Light malt extract adds approximately 42 points per pound per gallon (ppg).

You could also just top off to a smaller volume, since it sounds like you aren't doing full-volume boils.
Or just ignore the gravity being off target, since who really cares? If the math is too difficult, just skip making adjustments.

Happy brewing!

 

[RM-MN]

I'm relatively new to brewing (About 6 batches in) and have a relatively simplistic question.

I just figured out the concept of adding DME to the cooled wort to bring FG up if it is low. My question, is WHEN does one add DME? My normal brew day has me dumping cooled wort into the bigmouth fermenter, then adding water.

I've read about some brewers adding DME at the end of the boil. How would you know where your FG is (and how much DME to add) if you're going to add water to the fermenter to bring the batch up to the 5 gal mark after the fact? I've also read of some adding DME (boiled in a bit of water) to the cooled wort in the fermenter, which makes more sense, but still how does one calculate the add amount?

I guess I'm basically lost on this, so any guidance you can lend is greatly appreciated!

The previous answer makes the assumption that you are brewing all grain. If you are just using extract, the extract will have all the sugars necessary and if you use the correct amount of water and extract, you don't need to adjust. It's typical for an extract brewer to show low OG because many recipes call for adding top off water. Taking a sample after adding the water usually gets the brewer concerned because the OG is too low. It really isn't, it is just that mixing the extract and water are difficult and the sample was more watery.

If in fact you are brewing all grain, then the possibility of low OG because of poor mash efficiency arises. To know quickly if this is the case, one would use a refractometer that has automatic temperature compensation as it only takes a few drops for the sample and the reading is nearly instantaneous. For a hydrometer sample you need much more wort and it needs to be cooled to the hydrometer's temperature rating, often 60 or 68 degrees. This takes a lot of time so waiting until the wort is cooled and ready to pitch the yeast is normal. Then if the OG is too low, boiling up a mix of water and DME, then cooling to add to the fermenter will work.

 

[Vintage Iron]

So, you're brewing all grain?

Take a pre-boil gravity. (Chill the sample. Adjust for temperature.)
If it's too low, add DME toward the end of the boil. Light malt extract adds approximately 42 points per pound per gallon (ppg).

You could also just top off to a smaller volume, since it sounds like you aren't doing full-volume boils.
Or just ignore the gravity being off target, since who really cares? If the math is too difficult, just skip making adjustments.

Happy brewing!

Thanks for the answers so far. Yes, I'm doing all-grain batches. I probably should have said that in my original post.

Here's the part I don't understand... If I am to take pre-boil gravity readings, how is that even comparable because I usually have to top off the cooled wort with cold tap-water, so it's obviously more concentrated than it should be at that point, correct? Does this only work when the pre-boil wort is right at 5 gallons?

I know that gravity is about brewing efficiency, but sometimes things don't turn out right and it would be nice to "tope things up" so to speak if they do show up low.

Thanks again for your help...

 

[philjohnwilliams]

I think perhaps the main question here is why do you have to top off in the first place, and how much are you topping off? A bit of information about your process might help ( Batch sparge, fly sparge, BIAB...?), but basically you should be able to hit your target volume +/- a quart or two, simply by adjusting your pre boil water volumes.

 

[RPh_Guy]

The target gravity points of 5 gallons will scale to your pre-boil volume.
Boiling & topping up are simply concentrating or diluting the sugar.

E.g. If it's 1.050 for 5 gal, it'll be 1.100 in 2.5 gal and 1.025 in 10 gal (assuming no equipment losses).

A recipe calculator should provide a pre-boil gravity.
When measuring volume of hot wort don't forget to account for thermal expansion

 

[brandonlovesbeer]

I add DME to the boil. But at the end of the boil while the wört is still hot I guess would also be fine.

Doing it cold? That’s a bit more difficult. You’d need to boil or heat it first. Which adds more liquid volume.

Just my experience

 

[Toga]

If you need to add post boil, boil up as much dme as needed in the least amount of water you can get by with. Boil for 10 min, cool, then add to fermenter. In my early all grain days, I did this a few times I fell short. Even did this the next day after fermentation has already taken off with good results due to a lack of dme on brew day to top off the batch. These days if I happen to fall short I just say eff it and let it roll.