Consistency issues

[ange0501]

I am trying replicate a recipe for about 5 batches now. I am shooting for 78% efficiency and land between 68-74% each time. My original gravitates range from 1.055 to 1.065, with final gravities ranging from 1.01 to 1.02.

I am wondering what could cause this even though I am doing the same thing each time? Same amount of water for batch and sparge and am consistently maintaining a 4 degree temp drop in my mash tun.

My only thought is the grain crush. But would it vary that much?

Thanks,

Geoff

 

[ange0501]

Recipe calls for a original gravity of 1.068 and a final of 1.016

 

[Toga]

describe your process and I'm sure someone will be able to nail it for you.
fly sparge, batch sparge, grains crushed by you or LHBS or another source?

 

[jessup]

there are so many variables it's impossible to say without extreme details.

what brand of grains are you using? age of grains when brewing, crush of grains (single/double crushed), how long did they sit after being crushed. were grains hydrated before mashing? now look at the process. fermentation temps in a controlled environment? temperature fluctuations possibly affecting your beer in primary?

we can go on and on about different variables, but only you know all the details. there are a million and 1 different possibilities. you should consider the fact that noone can replicate their own batches perfectly. all the big guys (BMC) blend their batches to stay consistent. RDWHAHB

 

[Grumpybumpy]

It already sounds like crush/source is his only variable. OP?

 

[soundsandsuds]

Are you checking your grain temperature before calculating your mash temperature and water amounts?

 

[ange0501]

I get my grains crushed at the LHBS. They are fresh grains as far as I am concerned, the store is very busy with all-grainers. They are single crushed. Should I double crush? Grains were not hydrated before mashing. Should they? I drop 4-5 degrees during mash. I batch sparge.

My recipe is 14.5 lbs of grain, with 11.5 lbs of Pale 2 - row. I mash in with 6.5 gallons of water for 60 min, with a batch sparge of 5 gallons sitting for 30 min. My mash is 160 degrees with my sparge 168 degrees. Both drop down 5 degrees or so by the end.

 

[dbhokie]

I know that one thing, I have read about and heard from members in here regarding consistency is in the mash out.

You have enzymes that are active (which is changing the taste, saccharides present etc) in conversion processes during your mash. In order to get consistency with your mash you would need to raise the entire temperature to knock these buggers out of these conversion processes, at the same time, with the same relative efficiency and methods time tables etc. A 168 degree sparge is what I do (but then I am not terribly worried about consistency yet), many I have seen say to go higher in order to stop these conversion processes and raise your entire grain bed temperature.

If this is a hoppy beer, then the hop taste is easy to replicate, but if it relies on yeast a lot for its taste (I know all do, but relies on esters more than hops), then you would want to be pitching the same amount of yeast to the relative same volume, as from what I understand under or over-pitching will cause different (not necessarily undesired), but different flavors.

EDIT: The mashing out stage as I understood it when I tried to get a better grip on amylase and carb chains, sugar profiles etc, is pretty un-important from what I have gathered to an average home-brewer. Seeking a repeatable brew with a close to identical sugar profile is when you may want to try it. Everywhere I have read it suggests not being necessary for a home brewer, or not needed etc. However almost every expert I have seen when they speak of repeatable identical brews suggests it as a method of consistency. It doesn't matter that it may produce no more fermentable sugars, the beta amylase enzyme denatures quickly 1t 160 degrees and the alpha amylase denatures quickly at 176, most mash out people recommend 170 as a grain bed temperature, putting it on an end of the alpha amylase denaturing quicker, and beta amylase being taken out of the equation basically. The thought being that, though it won't negatively affect (neccessarily) the taste of your beer, and may only mildly increase efficiency if any (which is why it is an un-needed step), it will preserve the sugar-profile, which is not limited to whether or not the mash has finished conversion, but rather amylase enzymatic activity. Even if you do an iodine test, and see that there are no long chain carbs left alpha and beta amylase continue to hack amylase apart.

If you are experiencing drastic differences in your brew it probably would have to do with something else in practice, but I just wanted to state what I had read at length and understand of the process of the alpha and beta amylase activities. Since your first batch wasn't done in such a way, the only way to match it entirely is to match the process including liquor, temperatures, times, hop schedules, fermentation schedules and temperatures, yeast cell counts close to the same.

I'm not trying to be combative just simply saying this largely un-needed step is sometimes recommended by a lot of experts and those with a lot more experience than me for stark consistency.

 

[Homercidal]

The experts seem to say that a mash out is not needed in the timeframe that a homebrewer sparges a 5 gallon batch, and the enzymes are already pretty much set at that point. Referring to Beersmith podcast including Denny Conn, John Palmer, etc. It was noted that some of them still do a mash out for other benefits, including thinner sparge and quicker to-boil times.

Did you use different water for these? Different water can affect the pH in different ways which can affect not only taste, but conversion rates.

Do you use the same thermometer? Check calibration? Calibration check on hydrometer? Measure gravity at consistent temp? Carefully measure water amounts? EXACTLY the same ingredients?

 

[william_shakes_beer]

Keep in mind also that the recipie calculators use AVERAGE yeild of sugars for a given malt. Each batch of malt has a grain analysis that is available if you know where to look. One batch of american 6 row will have a different sugar available from the next, even whenb produced by the same maltster. I just keep a bag of pale DME on hand and top off using a formula I wrote that takes into account the current SG, current volume, and desired SG and volume. That allows me to hit my OG into the fermenter fairly consistently. Of course there are those that say I'm not doing AG. To those people I say pfffffth