System Test with water - have some more questions

[bru-ster76]

Hey!

I was hoping to brew this weekend, but there was way more things I needed to dial in before I jumped in, and I'm glad I did a system test with water only as I have come up with several questions from the process.

My system is a 65000BTU burner, 9G Kettle and 30 plate chiller. I boiled 6.25G of water, which is what my kit is going to require and it boiled for 60mins on a good solid rolling boil. I ended up with 4.75G (measured after chilling to 73F). Chilling took ~15mins to get that 4.75G to 73F. Now I have 3 groups of topic-based questions about this process.

1. I had reduced my burner after I got it boiling, but kept enough heat to keep it at an aggressive boil. Could I have reduced my heat further to lessen my boil off? (I was hoping to be closer to 5.25, but wasn't that lucky)

2. Should I aim to chill faster and settle at a higher temp? I was planning on fermenting at about 67F so I wanted to see if I could hit that temp to pitch at roughly the same temp as fermentation. Does this matter that much? Can I keep a lid on the wort while I clean up to further drop that temp before pitching, or is it best to begin pitching right after it's chilled?

3. I've read about trub, how much can I expect to leave in the kettle? my 4.75G was everything from the kettle, I just wonder if I should expect to leave everything below the ballvalve level behind or try and tip the kettle to get it out into the chiller.

Thanks in advance!

Here's a photo of my system.

 

[Pie_Man]

1. Yeah, you can probably lower your heat a little. The boil should be rolling, but it doesn't have to be aggressive. Alternatively, you can start with a larger pre-boil volume.

2. Not at all. Chilling to 73F in 15 minutes is more than adequate.

3. If you want to leave behind the liquid and trub below your ball valve, you will have to compensate for that loss with a larger starting volume, so measure the volume below the ball valve and add that to your pre-boil volume. It's not really bad to have trub in your fermenter, it may make cleaning your plate chiller more difficult (I don't use a plate chiller, so I'm not entirely sure). You can try using a pick up tube which should get most of the liquid off the bottom and leaving some of the trub behind.

 

[bru-ster76]

I had been adjusting the gas output every so often to try and hit my 1G boil off, but I suppose that was a mistake and I should have noted the valve position after setting it to maintain a rolling boil and just determined what the boil off was and adjusted by increasing original water volume. Should I do another test with this philosophy, or just wing it on brew day?

Can I keep the wort covered to further cool while I clean up, or should I pitch the yeast at the chilled temp of 73-75F?

Wouldn't adding more water to compensate for trub left behind reduce the OG as it would be more dilute? Instead of 5.25G for the total sugars, I'd need 5.5G to afford the .25G I'd leave behind, making the wort more dilute, no?

 

[Cyclman]

If you have to add a little water to the fermenter, it won't hurt anything, as long as you use the same filtered / bottled water you brewed with.

Can you control fermentation temperature, if so, pitch high then cool it. If not, I'd cool then pitch.

Leave out what trub you can, but don't obsess over it, it doesn't really matter much. If you get most of the liquid, out, it will have minimal OG effects.

 

[Pie_Man]

It's probably a good idea to test your system to calculate the boil off rate. If you choose to wing it on your next batch, that wouldn't be terrible either. I'd probably assume a 1.25 gallon per hour boil off rate.

For ideal fermentation, you're better off pitching lower than 72-75F. In general, I like to pitch at, or near, the low end of the yeast's temp range and let the beer rise to a given temperature. Pitching warm can create too many esters and/or off flavors. In addition, if you're pitching at 75, you're fermenting too hot for almost every yeast strain. If you're pitching at 75 then lower the fermentation temperature, you're shocking the yeast a little bit and probably causing some of them to go dormant.

Most brewers avoid covering their cooling wort because of DMS. DMS is a flavor compound that produces cooked corn and/or vegetal flavors and is mostly created when lower kilned malts (pale malts, pilsner, etc.) are at temperatures above about 150-160F. Boiling your wort drives off DMS. And cooling your wort relatively quickly is also a generally accepted principle to reduce DMS. I suppose if you're below the DMS temperature range, then you can cover the wort with minimal risk.

Yes, what you say about the sugar dilution is true. What I was referring to in my third comment was if you're going to leave behind the wort below the valve, you should compensate for that loss with a larger pre-boil volume. For instance, let's say there is .25 gallons below the valve. You should compensate for this loss by adding .25 gallons to your mash and/or sparge volume. In addition, you will have to increase your grain bill to compensate for the lost sugars. Anytime you lose sugars and wort volume in your process, you reduce your brewhouse efficiency. It's not necessarily a bad thing, and on a homebrew scale, it's easy to compensate for the losses.

Good questions. I hope this helps.

 

[bru-ster76]

Yep, that makes sense Pie Man, but I'm a DME/specialty grain kit, which is why I was concerned about the addition of more pre-boil volume. I don't think there's anything I can do to compensate for the predetermined amount of DME, is there?

Having said that... If I do another boil-off rate test and determine I boil-off 1.25G/hour, I should be able to add the extra .25G of water (more than the recipe calls for, which is 6.25) and end up at the 5.25G the recipe is aiming for. If I leave any behind, I'll have less beer, thus a decreased brew efficiency, but the right OG, correct?

I've made a fermentation chamber, so I was hoping to be able to chill the wort into the 65-68F range and pitch right away, but my chiller only gets me down to 73F, in 15 mins. I think I should be safe for DMS because it was chilled so quickly from boil, which is why I was thinking I could cover it and let it sit while I cleaned up to drop it a few more degrees before pitching.

Sometimes I wish I was a "good enough" type of guy, but I am a perfectionist and don't do mediocre very well.

 

[Pie_Man]

Yep, that makes sense Pie Man, but I'm a DME/specialty grain kit, which is why I was concerned about the addition of more pre-boil volume. I don't think there's anything I can do to compensate for the predetermined amount of DME, is there?

Having said that... If I do another boil-off rate test and determine I boil-off 1.25G/hour, I should be able to add the extra .25G of water (more than the recipe calls for, which is 6.25) and end up at the 5.25G the recipe is aiming for.

It's probably best to think about this in terms of gravity points. If the recipe says the OG is 1.060 at 5.25 gallons, that's 315 total gravity points (60 * 5.25). It doesn't matter if your pre-boil volume is 6.5 or 10 gallons, so long as it's boiled down to 5.25 gallons, you'll have an OG of 1.060.

If I leave any behind, I'll have less beer, thus a decreased brew efficiency, but the right OG, correct?

Exactly. If you leave wort behind in the kettle, you're leaving behind gravity points. For this reason, it's probably best to give the kettle a little tip and try to get as much wort into the fermenter and still leave as much of the trub behind, but don't be paranoid about the trub. That's the easiest thing to do.

In the above example, you'd lose 15 gravity points if the volume below the valve was .25 gallons and you had 5.25 gallons at the end of the boil, (315 * (.25/5.25)). So, after the dead space loss, you'd have 300 gravity points at 5 gallons, or an OG of 1.060. As you said, less beer, correct OG.

If you really wanted the correct OG at the recipe's specified volume, but had a dead space in your boil kettle, you could add extra DME to compensate for the dead space loss. The math gets a little tedious, and it's too late for me to try and solve that now, but it is technically possible; however, probably not worth the effort and easier to just tip the kettle a little bit.

I've made a fermentation chamber, so I was hoping to be able to chill the wort into the 65-68F range and pitch right away, but my chiller only gets me down to 73F, in 15 mins. I think I should be safe for DMS because it was chilled so quickly from boil, which is why I was thinking I could cover it and let it sit while I cleaned up to drop it a few more degrees before pitching.

That should work. Here's my procedure. I live in Florida and it's difficult to cool below 80F in the summer. I transfer from my boil kettle to my carboy after cooling to about 80-85F with my chiller, then I cover the carboy opening with paper towels dampened with starsan, place the carboy in my ferm fridge and wait until the wort cools to pitching temperature, then aerate and pitch.

 

[bru-ster76]

Thanks for the explanations. It's all starting to make good sense. Is the 60 pts per gallon an arbitrary number for showing the calculation or is it a fixed number when talking gravity points?

I like your idea of the chilling routine, but am curious about why you use paper towel and not sanitized aluminum foil. Any reason?

I did another boil test today, and kept the gas constant, but probably too much still... I moved just inside the garage this time, where I was fully outside yesterday. I boiled 6.5G down to ~4.7G in the hour (6.5 - 4.7 = 1.8). Way more than I was hoping, but is what it is. So now I know that I can start with just over 7G (5.25 + 1.8 = 7.05G), to hit my expected OG, correct?

I ended up with a few bugs in the boiled water, which makes me think if I should be boiling with a lid on or not? Thoughts on this? I had read to do an open boil, but bug beer doesn't sound too appetizing.

 

[Pie_Man]

Yes, 60 was an arbitrary number to illustrate the calculations.

I suppose you could use foil or a paper towel, or anything you like. I read a brewing article that referenced chemistry labs using a gauze-like material to cover samples which gave me the idea to use starsan dampened paper towels (2-3 folded over). I do put a rubber band around them to keep it tight against the carboy opening.

Sounds like you got your starting volume figured out. If you want to get a lower boil off rate, you may need a more efficient regulator to better control the propane fueling the burner, or perhaps a more efficient burner. 1.8 gallons per hour is fine though.

For the DMS reason mentioned above, it's advisable to use an open boil; however, if you're extract brewing, the extract has already been boiled by the manufacturer, so you can probably get away with a covered boil, maybe vent it a little bit.

 

[Frige]

I picked up a 5 gallon paint strainer from home depot and pour my wort trough it. That way I get every last drop out of my bk. After the boil if I need more water I just add it. No problem and I always get beer at the end. So crank it up remain calm and learn as you go.

 

[JoppaFarms]

Sound advice and great explanations here. I would mention that you will boil off more water than wort in practice (at least that is my experience). So you may find that you over shoot your volume very slightly if you are using your pure water boil-off rate when you actually brew. No big deal. One more thing regarding the boil, it doesn't have to be a tumultuous boil, it can be a gentle boil, so long as you are getting the liquid to turn over in the kettle. When I brew, I adjust the flame to keep it right at a rolling boil and that reduced my boil off rate to right at 1.0 gallons from 1.5 at a full vigorous boil. Good luck on your first brew, and remember, there will be beer at the end no matter what!

 

[bru-ster76]

Ok, I'm going to take this all into consideration on brew day.

If adding water is the accepted method for being over expected OF due to decreased volume, what is the preferred method when under OG, too much water volume. More boiling? I read that it wasn't recommended.

I'm using filtered local tap water, btw. It is some of the best water in the world and doesn't taste of anything bad. Can I add this directly into wort if more volume is required, or should I boil it first, or use a different kind of water for post boil top off?

 

[JoppaFarms]

There's really no need to hit the exact gravity spot on (unless you're a perfectionist), especially on your first (or second or third) attempt, because you're still dialing in the system. You may over/undershoot volume and/or gravity depending on a large number of variables. You could add water to make-up for overshooting gravity, and I would suggest boiled and cooled water just to be safe, but then you run the risk of adding too much and then diluting and undershooting gravity or then overshooting volume. Plus you're having to take more samples etc, seems like too many points where you could infect what would have been a perfectly delicious batch of drinkable beer (after fermenting). I'd just take what you learn from that batch (i.e. if you over/under shot volume or gravity) and adjust your next batch appropriately.

And as far as water goes, I've heard this said a lot, "if it tastes good, brew with it". If it's tap water I'd find out if you have chloramines in it before you try and mash with it and perhaps use a Campden tablet or let it sit uncovered over night. You definitely don't want those chemicals in your water when you brew. Hope this helps!

 

[bru-ster76]

Thanks for the response. Your rationale makes sense. Being a perfectionist, I am over analyzing it, mainly cause I'd like to end up with a brew that impresses myself rather than be discouraged about my initial efforts. I see your point though... I shouldn't worry too much about the gravity as it will be tasty beer regardless if its above or below its expected ABV.

Although I can't taste it, I asked a friend who works for our city in the water dept,. who's confirmed that only chlorine is added. Does chlorine require boiling as well, or just chloramine?

I won't sorry about having too much volume left after boil either on this go, but what is the appropriate method for dealing with it when boiling longer introduces unwanted side effects?

Thanks again.

 

[Pie_Man]

You have a pretty rapid boil off rate. If you're under gravity and over volume, simply boil for a little longer.

Stupid mobile app

 

[Pie_Man]

You have a pretty rapid boil off rate. If you're under gravity and over volume, simply boil for a little longer. A few extra minutes isn't going to make a big difference. RDWHAHB

I would remove the chlorine from your water. When yeast interact with chlorine during fermentation, they produce chlorophenols, plastic and/or vinyl like off flavors. If it's a little bit of top off water, you can probably get away with using straight tap water. Otherwise, I would remove the chlorine.

 

[bru-ster76]

Sounds good. I'm assuming that as long as I'm not mashing with chlorinated water, (won't be starting AG until I get a few good batches under my belt), I can use carbon filtered tap water for boiling extract and the chlorine will be reduced to nothing with no other intervention. I'm starting with 0.5-0.8ppm of chlorine in my city water.

If I add water, I'll follow your recommendations.

Thanks!