Can you stop yeast before it gets to dry and if so how?

[tlc]

I just got done splitting my first 5 gallons into two 2.5 gal batches and did one with a back sweetening of ajc and the other with a back sweetening of pear juice boiled down to a concentrate and bottling them. They both taste amazing just as a still cider (my wife and a couple of friends opinions). You can taste the subtleness of cinnamon and vanilla but not overpowering. I can't wait to see how they taste carbonated. I will be cooler pasteurizing when the test bottle is ready. I couldn't have done this with out everyone's help...Thank you for all the great advice!!!

 

[tlc]

I cooler pasteurized them to day and I had them in 125deg sink water and then put in a cooler with water at 160deg and internal temp of bottle was 150 deg so I left them in the cooler for 20 min and then removed and let sit on counter to cool down, I was shooting for 160 deg so will this be enough or do I need to do it again. I had to go to work so I didn't have time to re do them so I will id I need to. They will probably all get drank on New Years Eve or sooner. Thanks for any advice and have a great day.

 

[tlc]

Will what I did be enough or??? don't want bottle bombs...Thanks

 

[Rick Stephens]

First few times I pasteurized I left a single open bottle full of water in with the cider bottles and then I could drop an instant read thermometer in it to see what temps I reached. If I got it over 150ƒ INSIDE the bottles, I would consider it good to go. I only did mine on a CampChef LPG stove in big canning pots where I could set temps exactly the way I wanted and could measure results. I don't think from your description that anyone can quantify your results for you since they were't there measuring temps.

 

[tlc]

That's good to hear. I used an open bottle of water with a thermometer in it and the temp was over 150deg for 10 min. The temp slowly climbed from 150 to 155 before starting to cool back down very slowly. I set them on the counter after I removed them 20 min later and they were still above 145 at last check before leaving for work. Of all nights to get called in for OT
Thanks for getting back to me,

 

[tlc]

Jim Rausch's cooler method would be just fine. However (as always) there are a couple of things to think about...

I think that you have read or downloaded the PDF "Cider Heat Pasteurising and Carbonation", if not see my post 25 Sept. Figure 6 in that PDF is basically the Cooler Method. You will see that by pre heating the bottles, you may reach a pasteurisation temperature over 70C and in fact in Fig 6, the method generated over 600PUs. So, pre heating isn't really needed as long as the desired bottle temperature is achieved, or you work with a low er than 80C bath temperature.

With higher pasteurisation temperature there may be two adverse side effects. Firstly, higher temperature means higher bottle pressure, and secondly too high a temperature can "cook" the cider.

The way that the Cooler Method and Pappers approaches work is that the volume of bottles and their contents cool down the bath temperature as it heats up the bottles, until some equilibrium temperature is reached (ideally around 70C or less). This all depends on how hot the bath is and how much hot water, and how cool the bottles are and how many. i.e. there are a few variables to manage.

In my test case, a ratio of 7:1 worked well (15 litres of 80C water and 2 litres of bottles and cider at 20C resulted in an equilibrium temperature of about 70C)

Have a look at a post by Jaypkk (3 Dec). There is a summary and a link to a research paper from Washington State University which demonstrates that pasteurisation of cider can be achieved at temperatures between 60C and 65C with short time exposure. Certainly it supports the idea that 30PUs or even less is fine for cider, and at the lower temperature, bottle pressure is unlikely to exceed 100 psi so the chance of bottle bombs is markedly reduced.

Having said that, there isn't any evidence that "overpasteurising" has any adverse effect on the cider flavour.

If you try the Cooler Method, I suggest having a water filled test bottle with a thermometer in the bath and simply remove the bottles when they have reached the pasteurisation temperature that you want. Generally the temperature distribution in the bottles stabilises in 10-20 minutes so your bottle core temperature will understate the temperature at the edges, This doesn't matter since the edges will be pasteurised a little more than the core of the bottle.

In any case, if they like it and drink it all on NYE, happy days... Merry Xmas!

Chalkyt,
I'm not sure how to actually calculate the PU's so based on what I did and the temps listed below can you see how many PU's I would generated and if you don't mind show me how the calculation works so I will be able to do it myself in the future...Thanks for your help.

 

[Chalkyt]

It usually takes a couple of weeks for significant carbonation to take place from low SG levels, so apart from anything else, gushers would be unlikely by NYE.

Some recent research from Washington State University reinforces the view that less than 30 PUs is more than enough for cider. In your case holding the bottles at 150F-155F for around ten minutes would generate over 50 PUs. Cooldown from this temperature would generate similar PUs due to the residual temperature of the bottles so you can be confident that you have "nuked" the yeast with something like 100 PUs and stopped any chance of refermenting.

 

[tlc]

That's what I was going for. I got confused with reading some post of some people putting the bottles in water at 150 deg and leaving for 15 min. I wasn't sure if that was 150 deg water and walk away or 150 deg after the bottle fluid temp was at 150 deg. Going forward I will monitor the fluid temp and when it gets above 150-155 deg then I will start the timer for 10 min. I feel good with around 100 PUs. I've got a lot to learn on pasteurizing. I opened a bottle a few minutes ago and it had a very nice fizz going on so I think I was around a 2.5 Co2 because I opened a Angry Orchard Cider and pored them side by side. (wife was impressed and likes the flavor). I couldn't have done it without everyone's help. I Hope everyone has a Great Christmas!!!

 

[Chalkyt]

Looks like our posts overlapped.

Calculating PUs is based on a formula developed by H.W. del Veccio and others in the 1950s. It is still used today. They found that pasteurisation starts to occur around 60C, and the amount of PUs generated increases exponentially with temperature beyond that. There is a very good post by Bembel (11 May 2016) that outlines a method of monitoring PUs by recording the time that bottles are at a particular temperature. I use a slightly different method where I record the temperature at each minute. This is easy to do with a phone stopwatch/timer.

In both cases, punching the times and temperatures into a spreadsheet makes life easy. I have attached a PDF of the the Excel spreadsheet that I use, with some data that might simulate your outcome. I find that this is good enough to monitor what is happening and when to remove the bottles from the water, etc. Unfortunately, "the system" doesn't allow me to attach the actual spreadsheet as an Excel file to the post, but can send you the various cell formulas if you want to make your own. Just let me know.

The del Veccio formula is... PU=t x 1.393 raised to the power of (T-60) where t= time in minutes and T= temp in C.

Here is a table that shows the exponential increase in PUs per minute as temperature increases.

Temp C	60​	61​	62​	63​	64​	65​	66​	67​	68​	69​	70​
Temp F	140​	142​	144​	145​	147​	149​	151​	153​	154​	156​	158​
PUs per minute	1.0​	1.4​	1.9​	2.7​	3.8​	5.2​	7.3​	10.2​	14.2​	19.7​	27.5​

So, you can see that at your bottle temperature of 150F for 10 minutes you will have generated at least 50 PUs (i.e. 5.2 PUs per minute X 10 minutes). Then if you calculate the PUs generated each minute at the relevant temperature during cooldown you will probably get another 50 PUs or so. The idea of using low temperatures and longer times is to minimise the pressure buildup in the bottles as the pasteurising heat drives the CO2 gas out of solution and creates bottle pressure. (see Andrew Lea's carbonation calculator (http://www.cider.org.uk/carbonation_table.xls)

Sorry if this sounds a bit "heavy" but it isn't, once you understand how heat pasteurisation works.

Cheers! Merry Xmas.

 

[tlc]

That helps a lot and thanks for the attachment...Looks like I got some homework to do.

 

[tlc]

How do I find the post by Bembel you are referencing.

 

[tlc]

Found it...