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Messages - nyakavt

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46
All Grain Brewing / Re: For those that measure mash gravity
« on: March 03, 2010, 12:42:39 PM »
I was more concerned that it might have some sort of linear error. Have you checked a known-Brix solution?

FWIW my last three single-infusion mashes were at 89%, 95%, and 94% of the values from Kai's chart. For the 89% batch, I don't have a lot analysis, so it assumes 80% DBFG and may not be accurate. The other two were domestic 2-row and are relative to the actual potential extract.

I did this but probably about a year ago.  May be time to check it again.  FWIW, the values from the refractometer don't seem to be too far out from the hydrometer samples post boil, the refractometer reading / hydrometer reading (in plato) I think has been 1.01 - 1.04.

I looked through the notes and came up with the following (hopefully this shows up ok  :-\):

batch        targ G  G@60  % conv  Gmshout % conv  mash temp
oktoberfest   17.3   13.8     80   17.8     103    151
dortmunder    15.7   13.4     85   15.8     101    151
dunkel        15.4   14.6     95   16.4     106    154
German Pils   15.6   13.5     87   15.6     100    148
Citrarillo    19.5   14.8     76   20       103    153
Alt           18.7   19      102   19       102    151.5
Munich Weiss  20.3   14       69   19.5     96     151
Pliney        19.7   18.2     92   18.2     92     150
Janet's Brown 19.8   18.3     92   19.4     98     154


Some of the readings are higher than 100%, I attribute this to not having the real malt sheets.  The ones I have been going by for base grains list the yield as a minimum, so the individual bags could be higher.

47
All Grain Brewing / Re: For those that measure mash gravity
« on: March 02, 2010, 06:47:55 PM »
For a long time now my standard mash incorporates a long (30-45 min) rest at 160 F which usually gives me full conversion after it is done. I have yet to take the time to plot the mash gravity over time.

I know you said that you do not yet have a plot of mash gravity over time.  I have found that whenever I check the mash gravity after raising the temperature (min 5 max 10 min) it has gotten up to 100% conversion.  Do you have a similar observation, or does yours take quite a while longer?

Along a10t2's line of questioning, how close are you after the sacc rest?

Quote
My malt is milled at about 0.7-0.8 mm (28 – 31 mil). I think my good conversion is helped by the fact that I do stir the mash, mash thin and hold that long rest at 160 F. But mashing with direct heat may not be a viable option for everybody since it does take a little more effort.

Assuming that the measurements taken are accurate I am also getting 100% conversion.  The water to grist ratio I use is around 2 qts / lb, (1.5 for bigger beers).  I get up to 160F by boiling 2-4 qts of the mash and adding back to the cooler.  I don't want to call it a decoction because I am only raising the temperature, not heating long enough to get a lot of flavor development.

48
All Grain Brewing / Re: For those that measure mash gravity
« on: March 02, 2010, 06:39:00 PM »
Are you checking your mash pH? 2-5°P low seems like a lot to me, especially after 60 minutes. My mashes are always within about 1°P of the theoretical values.

Is your refractometer calibrated?

pH is checked with colorpHast strips and I don't close up the tun until the pH is between 5.3 and 5.6 (5-5.3 on those strips) as measured on a sample that is not warm to the touch.  I measure right after stirring, maybe only a minute after making a salt adjustment.  Sometimes it comes in right at 5.3, other times it is too high or too low, but this is what I shoot for.  I have only checked the mash pH at the end of the rest a couple of times to see if I was getting an inaccurate reading early, the measurements both times have agreed with the early measurement.  Those strips really are borderline for being useful in the brewing range.

I agree it seems low, especially for the nearly 100% pils malt grist.  I'll have to check my notes when I get home to be sure, hopefully I wrote down the 'incomplete' conversion reading.

The refractometer is calibrated on brew day once with a drop of tap water.  I used to have to adjust it a lot when I first got it, but it rarely needs adjusting now.  I try to remember to check every time, but it's conceivable that I got lazy once or twice.

49
All Grain Brewing / For those that measure mash gravity
« on: March 02, 2010, 02:19:59 PM »
Do you find that a mashout is necessary to ensure 100% conversion?  I have been measuring mash gravity for the past 20 batches, but it has only been accurate for the last 7 or so since I started cooling samples in a sealed container.  I have thus far found that every beer but one required raising the mash temperature at the end (sort of a mashout, but it varies from 158-170F depending on how much water is in the tun) to ensure complete conversion.  After a 60 minute sacc rest I am several Plato low, I think 2-5 but I'd have to check my notes to be sure.

These results are confusing since I have heard a lot of people saying that a low adjunct mash is converted 'as soon as it hits the water'.  There may be some starches that are not gelatinized at the mash temperatures I am using, but I'd like some independent confirmation of this from other brewer's observations.

Some details:
Grist has been mostly Best Pils or Best Munich, with a 2-row and wheat base beer thrown in
Mill gap: .025" set by feeler gauges on the Barley Crusher
Grist is conditioned prior to milling with 1-2% water by mass
Mash temp has been 151-154 over the 7 beer span, losing 1-3° in the hour
Strike water volume is accurate to the nearest quart
Grist is measured on a scale accurate to the nearest 0.1 oz
Temperature is measured with the pro-accurate digital thermometer from NB, 32.0F in icy water and 213-214F at boiling (for wort).
Sample is gathered either into a 20 mL screw top test tube and immediately sealed, or in a 10 mL medical syringe. 
The test tube is cooled by submerging in a water bath, and the syringe is cooled by running cold water over the outside.  I tried submerging the syringe before but some water mixed with the sample and contaminated the reading.  Both methods agree exactly when taken on the same mash.
Sample size is typically 1-5 mL read on an ATC refractometer after cooling until it does not feel warm to the touch.
Grist potential OG is calculated from typical malt analysis sheets for base malts and values found in Home Brewing Wiki's Malts chart for each malt used.  Formula used: expected FW extract = 100 * grain laboratory extract / (R + grain laboratory extract) where R = water to grist ratio.

50
General Homebrew Discussion / Re: Olive Oil
« on: February 24, 2010, 06:12:32 PM »
Here's an update for me, my latest lager has taken over 3.5 days to start bubbling in anger.  I may have underpitched a bit (~100 mL of harvested slurry), but there was also very little air introduced in the transfer from kettle to fermenter, and no stir plate this time.  I remember reading about a slower fermentation when OO was the sole method of aeration.  This seems excessively slow.  Trying the mix stir or stir plate next time could give some valuable data, but since the pitching rate is changing too I don't know how valid a comparison this will make.

51
General Homebrew Discussion / Re: Modern German Brewing Practices
« on: February 19, 2010, 12:57:32 PM »
Actually, I think I just found what I was looking for
Quote
The Hochkurz mash has become the standard mashing schedule for beers brewed in Germany. Especially large breweries like it because it doesn’t require decoction and can be done in less than 2 hours which fits well with their desire to be able to mash a new batch every 2 hours. It uses 2 different sacharification rests; one for each group of amylase enzymes. A low temperature rest favors the beta amylase and sets the fermentbility of the wort. A high temperature rest favors the alpha amylase and completes the starch conversion.


So this is like a single infusion with a mashout?

52
General Homebrew Discussion / Re: Olive Oil
« on: February 19, 2010, 12:53:34 PM »
OO is my primary aeration method as well, simply because for the longest time I didn't have anything else.  I have not done a split batch, so I'm only going by the attenuation numbers to prove to me that it's working.  There could definitely be a difference in flavor (and I'm sure there is!) vs. traditional oxygenation, and to compound matters sometimes the yeast that is pitched is grown on a stir plate, so its getting a fair amount of oxygen right there.  I'd love to do a comparison of OO vs. mix-stir, starting with fresh yeast, but I guess I'm just so darn lazy, and the fermenting fridge only holds one fermenter.

Since I switched over to the SP10 burner the kettle sits a bit lower to the ground, so there is a lot less foaming when I transfer to the fermenter.  I have noticed these lagers take a good 48 hours to get going, one of them took 72 hours, which is longer than I remember.  The very first beer had some sulfur, which could have also been caused by slightly underpitching since this yeast was grown on a stir plate and should have had plenty of oxygen.  John Palmer made a comment on a recent podcast that said you could oxygenate by a stir plate alone, but I don't have exact numbers so I won't misquote him.

In the brewing industry, it seems that several brewers (New Belgium, de Struise) tried olive oil aeration but most or all of them gave it up for one reason or another.  This would be pretty strong evidence that it does not provide everything that O2 does, or the flavor is somehow different.  I'm not seeing a big detriment to the beers I'm making, so its hard for me to change what is working.  But eventually I'd like to do some comparisons in the pursuit of better beer if I could kick this laziness!

53
Kegging and Bottling / Re: How much slurry for bottle conditioning
« on: February 16, 2010, 12:31:54 PM »
The rate that Sierra Nevada uses is 1 billion cells / L, and that's to bottle condition filtered beer.  If I rinse the yeast slurry of any trub, then I usually go with 3 billion cells/mL, which is around 6-7 mL for a 5 gal batch.  If the slurry is older you'll need more.  The tricky bit will be getting it evenly mixed in the bottling bucket.

54
All Grain Brewing / Re: Mash Hops vs. FWH
« on: February 12, 2010, 01:48:24 PM »
The recipe on Fred's site is the new one that was in Zymurgy this summer.  Fred got that one from Vinnie after the 2009 NHC.  No Chinook and more Simcoe.  No mash hops in the new one

Thanks for clearing this up, it's hard to sift through all the information out there unless you were around when it came out.

55
General Homebrew Discussion / Re: Bottle conditioned Stout.
« on: February 12, 2010, 01:34:11 PM »
The chemical reactions responsible for beer 'mellowing', loss of hop flavor/aroma/bitterness, and beer staling happen faster at warm temperatures.  The physical process of fine particulates settling out of the beer happen best at cold temperatures.  Any of those temperatures would work, it will just favor one or the other.  I like to do a period of warm conditioning (usually in the fermenter) before packaging and lagering, but that's just me.  Once you like the flavor you should keep it as cold as you can if you plan to keep it around for a very long time.  Before I got into kegging I would just leave all the beer in the 65-75° closet, and some of them started to show evidence of staling (slight cardboard flavor) at around the 6 month mark.

56
All Grain Brewing / Re: Mash Hops vs. FWH
« on: February 11, 2010, 01:32:26 PM »
And where can one find the old recipe?

I think Vinnie was talking about it in his firs appearance at BN Sunday session.

That one linked on Fred's site, AFAIK, is the original Pliny homebrew recipe.  I seem to remember them discussing that the recipe was 'out there' on that first Sunday Session, but for some reason not actually giving the recipe on the show.  It's been so long, I'd have to listen to it again to be sure.  

Vinnie did mention Amarillo in the current rendition, as well as hop extract for the early bittering.  I think the hop extract is critical if you want to make a clone of the current commercial version.  I brewed one using the original recipe and it seemed far more bitter than the commercial version I had.  Still a fine beer mind you, but it was more like the longshot DIPA than Pliny.  Not quite as harsh as the longshot beer, but not as mellow as the Pliny.  The aroma was absolutely incredible though, it's like I took 20 lbs of citrus zest and threw it in the fermenter.

57
All Grain Brewing / Re: Chris Colby on malt conditioning
« on: February 10, 2010, 12:59:02 PM »
You guys made good points and I appreciate that. Maybe it is that this technique is not widely used and thus not discussed often enough for me to have noticed that it has been brought up many times before. I guess me trying to claim credit for "bringing it to home brewer's attenuation" was a bit too much and I take that back. I should have done some more research. But I never claimed to have come up with it myself and I do properly cite my sources.

I don't know, Kai is the only one I heard talking about it, at least to us homebrewers on the forums.  HBD was something that was a little before my time in homebrewing, so I don't know if I would have found out about conditioning without Kai's posts and site, and certainly not in as much detail.  I can at least give him credit for introducing me to malt conditioning, and I think his site is responsible for bringing conditioning to a much wider audience, at least if the recent forum threads here and on the NB forum are any evidence.

58
General Homebrew Discussion / Re: Brix to plato conversion
« on: February 09, 2010, 10:37:32 PM »
I plugged Blatz's formulas into excel and got an average difference of 0.87 SG points between the two scales.  Plotting Plato vs. Brix, the trend line is:

PLATO = 1.0000267*BRIX - 0.0009006
R² = 0.9999999

This was a curiosity because the refractometer conversion factor is defined as:

Refractometer reading in Brix / Hydrometer reading in Plato

I guess the refractometer conversion factor takes care of the slight difference in the scales by its definition, I was thinking that there was some unaccounted for error.

So suppose you make up a solution of water and sugar that measures 1.04003 SG, or 10 Plato.  Since this is pure sugar, the Brix reading will also be 10 Brix.  But if the sugars in solution are made up of more than just sucrose, as in wort, the Brix reading will be slightly higher.  10.4 if we use a 1.04 refractometer conversion factor.

Thanks for the explanation.

59
General Homebrew Discussion / Brix to plato conversion
« on: February 09, 2010, 07:21:39 PM »
Everything I've read online say that Brix and Plato are 'close enough' for brewing.  Well this isn't very satisfying to me, I would like to make that decision myself.  Promash never displays the same value for plato and brix when I enter my refractometer reading.  So, how does one convert between the two?

I found this table which says Plato = 1.04 * Brix.  I'd like to get another source or get verification of the accuracy of this conversion.

60
Questions about the forum? / Re: Show topic titles only in search results?
« on: February 08, 2010, 02:03:45 PM »
So, is this possible?

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