Repitch or unfermentable

[bken620]

Newer to all grain, still figuring the whole process out.

Process:
Heat up strike water
Batch Sparge for 60 min
15 min Mash out

So I think my strike water was too hot, I got it up to 180F then mashed in, it only dropped to 170F, I just left it not knowing that it would produce unfermentables...my bad.
I also left my Gatorade mash tun spigot open while I was doing my first mash, lost an undetermined amount of water that had to be made up later.

Then got my strike water back up to 180F and mashed out.

Pre boil gravity was 1.042, added some dry malt extract and After everything was said and done, I only missed my OG by 4 points, at 1.054, when it should have been 1.058.

Pitched my rehydrated safale us-05, after getting my wort temperature down to 70F.

Got signs of fermentation about 36 hours later and then left for vacation.

It's been 15 days since brew day so I wanted to check my FG, and to my dismay it was only 1.030.

My fermentation chamber was set to 69F, but the beer was down to 64F when checking the gravity.

Here's my question, do I warm up the chamber to 70F and repitch, or are there to many unfermentables and should I just call it a day, rack it to my kegs and call it a learning experience?

 

[Gnomebrewer]

At that mash temp, beta amylase (the one that makes more fermentable sugars) is denatured very quickly. Alpha amylase did the bulk of the conversion meaning you will have lots of un-fermentable sugars (I'm somewhat surprised you got the level of conversion that you did; did you do an iodine check for unconverted starch?).

Did you use a refractometer, or hydrometer to test the final gravity?

I'd expect your ferment is done. Does it taste sweet? Finishing at 1.030 might still be drinkable if it is fermented out - you could go ahead and keg. Your other option is to add some dry-enzyme to the fermenter which will help to convert some non-fermentable to fermentable sugars. The problem with this is that you'll end up with a very dry beer.

 

[madscientist451]

Some things that work for me:
--Use hot tap water to pre-heat mash tun while strike water is heating up.
--Use on line strike water calculator to figure what strike temperature should be. Guessing at the strike temperature isn't going to work.
--Heat sparge water to 190-195 for mash out

 

[cannman]

The next time you over shoot your temp, bring it down to where it SHOULD be and then throw in another cup of crushed base malt. The denatured enzymes are gone (which is why you have such a high FG), but the new ones from the cup of grain will chew through everything for you, even if it takes a little bit longer (learn about iodine test).

Good luck!

 

[bken620]

At that mash temp, beta amylase (the one that makes more fermentable sugars) is denatured very quickly. Alpha amylase did the bulk of the conversion meaning you will have lots of un-fermentable sugars (I'm somewhat surprised you got the level of conversion that you did; did you do an iodine check for unconverted starch?).



Did you use a refractometer, or hydrometer to test the final gravity?



I'd expect your ferment is done. Does it taste sweet? Finishing at 1.030 might still be drinkable if it is fermented out - you could go ahead and keg. Your other option is to add some dry-enzyme to the fermenter which will help to convert some non-fermentable to fermentable sugars. The problem with this is that you'll end up with a very dry beer.

Hydrometer for everything.

It's a sweet stout (left hand milk stout clone), did it for my wife because she loves that beer.

It's very drinkable, and my wife said it tasted close to the LHMS.

I think to leave it sweet I'm just going to rack it to my kegs.

 

[bken620]

Some things that work for me:
--Use hot tap water to pre-heat mash tun while strike water is heating up.
--Use on line strike water calculator to figure what strike temperature should be. Guessing at the strike temperature isn't going to work.
--Heat sparge water to 190-195 for mash out

I used brew target and they told 163, but I also read some different online posts from people about sparge water that they always heat there's up to 180 and have no problems. I now know they're either putting in cold water, lying or having the same thing happen to me that happened to them.

 

[bken620]

The next time you over shoot your temp, bring it down to where it SHOULD be and then throw in another cup of crushed base malt. The denatured enzymes are gone (which is why you have such a high FG), but the new ones from the cup of grain will chew through everything for you, even if it takes a little bit longer (learn about iodine test).

Good luck!

What is this iodine test you speak of...?

 

[GHBWNY]

Newer to all grain, still figuring the whole process out.

Process:
Heat up strike water
Batch Sparge for 60 min
15 min Mash out

So I think my strike water was too hot, I got it up to 180F then mashed in, it only dropped to 170F, I just left it not knowing that it would produce unfermentables...my bad.
I also left my Gatorade mash tun spigot open while I was doing my first mash, lost an undetermined amount of water that had to be made up later.

Then got my strike water back up to 180F and mashed out.

Pre boil gravity was 1.042, added some dry malt extract and After everything was said and done, I only missed my OG by 4 points, at 1.054, when it should have been 1.058.

Pitched my rehydrated safale us-05, after getting my wort temperature down to 70F.

Got signs of fermentation about 36 hours later and then left for vacation.

It's been 15 days since brew day so I wanted to check my FG, and to my dismay it was only 1.030.

My fermentation chamber was set to 69F, but the beer was down to 64F when checking the gravity.

Here's my question, do I warm up the chamber to 70F and repitch, or are there to many unfermentables and should I just call it a day, rack it to my kegs and call it a learning experience?

The initial minutes of mash temp are the most critical. If it was too high, it limits the abilities of enzymes to convert the sugars and therefore, a lot of unfermentables will be produced resulting in a higher FG. Re-pitching will not re-start it since there are no sugars left for the yeast to feed on. You could add DME and/or re-pitch, but the beer will be drier and further from original style, which is also true being too sweet. So take your pick.

I did the same thing last week, and unfortunately, I had to let it ride and be what it was going to be. It was a dry, crisp blonde that ended up with a slight sweetness. Live/brew and learn.

 

[cannman]

What is this iodine test you speak of...?

http://howtobrew.com/book/section-3/how-the-mash-works/the-starch-conversion-saccharification-rest

Under Conversion check:

The brewer can use iodine (or iodophor) to check a sample of the wort to see whether the starches have been completely converted to sugars. As you may remember from high school chemistry, iodine causes starch to turn black. The mash enzymes should convert all of the starches, resulting in no color change when a couple drops of iodine are added to a sample of the wort. (The wort sample should not have any grain particles in it.) The iodine will only add a slight tan or reddish color as opposed to the flash of heavy black color if starch is present. Worts high in dextrins will yield a strong reddish color when iodine is added.

What do these two enzymes and temperatures mean to the brewer? The practical application of this knowledge allows the brewer to customize the wort in terms of its fermentability. A lower mash temperature, less than or equal to 150°F, yields a thinner bodied, drier beer. A higher mash temperature, greater than or equal to 156°F, yields a less fermentable, sweeter beer. This is where a brewer can really fine tune a wort to best produce a particular style of beer.

 

[antony]

As a milk stout, 1.030 isn't horrible...mine usually finish at 1.020 or 1.022. +1 to everyone that says move on and learn for next time. The high mash temp was the culprit but its a sweet stout so you probably couldn't have picked a better style to learn the lesson with.

 

[kh54s10]

As said, being within a few degrees of mash temperature is very important. You started about 15 degrees hot. That and the fact that the recipe will contain a lot of unfermentable sugars leads to the high FG. I looked at a recipe and it called for 1.022 for the FG So you are 8 points high.

I don't think there is much that you can do. Keg it and see if it is drinkable.

Then pay attention to getting the proper mash temperature on your next batch. 168 is close for my strike temperature for average batches.

With batch sparging, just skip the mash out step. You drain and start the boil relatively quickly so stopping conversion is not critical. This is a step more for fly sparging where that process might take up to an hour while conversion is still taking place.

The temperature of the sparge is not critical either. You are just rinsing more of the sugars out of the grain husks. Warm water may makt it easier. I always just approximately 168-170 degrees.

 

[GHBWNY]

As said, being within a few degrees of mash temperature is very important. You started about 15 degrees hot. ...pay attention to getting the proper mash temperature on your next batch. 168 is close for my strike temperature for average batches.

Same. If it starts a little under mash temp, the lesser of two evils is that bringing it up to temp is safer and easier and than shocking the mash with water 10 degrees too hot and discover after the fact you need to bring it down.

 

[bken620]

Thanks for all the replies, you people have given me a lot of awesome information. I really have learned a lot.

I'm going to rack to my kegs and embib.