Here is a link to a wealth of information on Sous Vide. This is where I did my research before I started. Below the link is information I copied directly from there...
http://www.douglasbaldwin.com/sous-vide.htmlYou were probably taught that there’s a “danger zone” between 40°F and 140°F (4.4°C and 60°C). These temperatures aren’t quite right: it’s well known that food pathogens can only multiply between 29.7°F (-1.3°C) and 126.1°F (52.3°C), while spoilage bacteria begin multiplying at 23°F (-5°C) (Snyder, 2006; Juneja et al., 1999; FDA, 2011). Moreover, contrary to popular belief, food pathogens and toxins cannot be seen, smelt, or tasted.
So why were you taught that food pathogens stop multiplying at 40°F (4.4°C) and grow all the way up to 140°F (60°C)? Because it takes days for food pathogens to grow to a dangerous level at 40°F (4.4°C) (FDA, 2011) and it takes many hours for food to be made safe at just above 126.1°F (52.3°C) – compared with only about 12 minutes (for meat) and 35 minutes (for poultry) to be made safe when the coldest part is 140°F (60°C) (FSIS, 2005; FDA, 2009, 3-401.11.B.2). Indeed, the food pathogens that can multiply down to 29.7°F (-1.3°C) – Yersinia enterocolitica and Listeria monocytogenes – can only multiply about once per day at 40°F (4.4°C) and so you can hold food below 40°F (4.4°C) for five to seven days (FDA, 2011). At 126.1°F (52.3°C), when the common food pathogen Clostridium perfringens stops multiplying, it takes a very long time to reduce the food pathogens we’re worried about – namely the Salmonella species, Listeria monocytogenes, and the pathogenic strains of Escherichia coli – to a safe level; in a 130°F (54.4°C) water bath (the lowest temperature I recommend for cooking sous vide) it’ll take you about 2½ hours to reduce E. coli to a safe level in a 1 inch (25 mm) thick hamburger patty and holding a hamburger patty at 130°F (54.4°C) for 2½ hours is inconceivable with traditional cooking methods – which is why the “danger zone” conceived for traditional cooking methods doesn’t start at 130°F (54.4°C). [Note that Johnson et al. (1983) reported that Bacillus cereus could multiply at 131°F/55°C, but no one else has demonstrated growth at this temperature and so Clostridium perfringens is used instead.]
Pasteurization is a combination of both temperature and time. Consider the common food pathogen Salmonella species. At 140°F (60°C), all the Salmonella in a piece of ground beef doesn’t instantly die – it is reduced by a factor ten every 5.48 minutes (Juneja et al., 2001). This is often referred as a one decimal reduction and is written D606.0 = 5.48 minutes, where the subscript specifies the temperature (in °C) that the D-value refers to and the superscript is the z-value (in °C). The z-value specifies how the D-value changes with temperature; increasing the temperature by the z-value decreases the time needed for a one decimal reduction by a factor ten. So, D666.0 = 0.55 minutes and D546.0 = 54.8 minutes. How many decimal reductions are necessary depends on how contaminated the beef is and how susceptible you are to Salmonella species – neither of which you’re likely to know. FSIS (2005) recommends a 6.5 decimal reduction of Salmonella in beef, so the coldest part should be at least 140°F (60°C) for at least 6.5D606.0 = 35.6 minutes.
The rate at which the bacteria die depends on many factors, including temperature, meat species, muscle type, fat content, acidity, salt content, certain spices, and water content. The addition of acids, salts, or spices can all decrease the number of active pathogens – this is why mayonnaise (with a pH less than 4.1) does not need to be cooked. Chemical additives like sodium lactate and calcium lactate are often used in the food industry to reduce the risk of spore forming pathogens like Clostridium species and Bacillus cereus (Aran, 2001; Rybka-Rodgers, 2001).
Pasteurization Time for Lean Fish
(starting at 41°F / 5°C and put in a 131–140°F / 55–60°C water bath)
55°C 56°C 57°C 58°C 59°C 60°C
Thickness 131°F 133°F 134.5°F 136.5°F 138°F 140°F
5 mm 2½ hr 1¾ hr 1¼ hr 50 min 35 min 30 min
10 mm 2¾ hr 2 hr 1½ hr 60 min 45 min 35 min
15 mm 2¾ hr 2 hr 1½ hr 1¼ hr 55 min 50 min
20 mm 3 hr 2¼ hr 1¾ hr 1½ hr 1¼ hr 60 min
25 mm 3¼ hr 2½ hr 2 hr 1¾ hr 1½ hr 1¼ hr
30 mm 3¾ hr 3 hr 2½ hr 2 hr 1¾ hr 1¾ hr
35 mm 4 hr 3¼ hr 2¾ hr 2½ hr 2¼ hr 2 hr
40 mm 4½ hr 3¾ hr 3 hr 2¾ hr 2½ hr 2¼ hr
45 mm 4¾ hr 4 hr 3½ hr 3¼ hr 2¾ hr 2½ hr
50 mm 5¼ hr 4½ hr 4 hr 3½ hr 3¼ hr 3 hr
55 mm 5¾ hr 5 hr 4½ hr 4 hr 3¾ hr 3½ hr
60 mm 6¼ hr 5½ hr 5 hr 4½ hr 4 hr 3¾ hr
65 mm 7 hr 6 hr 5½ hr 5 hr 4½ hr 4¼ hr
70 mm 7½ hr 6¾ hr 6 hr 5½ hr 5 hr 4¾ hr
Pasteurization Time for Fatty Fish
(starting at 41°F / 5°C and put in a 131–140°F / 55–60°C water bath)
55°C 56°C 57°C 58°C 59°C 60°C
Thickness 131°F 133°F 134.5°F 136.5°F 138°F 140°F
5 mm 4¼ hr 3 hr 2 hr 1½ hr 60 min 40 min
10 mm 4¼ hr 3 hr 2 hr 1½ hr 1¼ hr 50 min
15 mm 4½ hr 3¼ hr 2¼ hr 1¾ hr 1¼ hr 60 min
20 mm 4¾ hr 3½ hr 2½ hr 2 hr 1½ hr 1¼ hr
25 mm 5 hr 3¾ hr 2¾ hr 2¼ hr 1¾ hr 1½ hr
30 mm 5¼ hr 4 hr 3¼ hr 2½ hr 2¼ hr 2 hr
35 mm 5½ hr 4¼ hr 3½ hr 3 hr 2½ hr 2¼ hr
40 mm 6 hr 4¾ hr 4 hr 3¼ hr 3 hr 2½ hr
45 mm 6½ hr 5¼ hr 4¼ hr 3¾ hr 3¼ hr 3 hr
50 mm 7 hr 5¾ hr 4¾ hr 4¼ hr 3¾ hr 3¼ hr
55 mm 7½ hr 6¼ hr 5¼ hr 4¾ hr 4¼ hr 3¾ hr
60 mm 8 hr 6¾ hr 5¾ hr 5¼ hr 4¾ hr 4¼ hr
65 mm 8½ hr 7¼ hr 6¼ hr 5¾ hr 5¼ hr 4¾ hr
70 mm 9¼ hr 8 hr 7 hr 6¼ hr 5¾ hr 5¼ hr
Pasteurization Time for Poultry
(starting at 41°F / 5°C and put in a 134.5–149°F / 57–65°C water bath)
134.5°F 136.5°F 138°F 140°F 142°F 143.5°F 145.5°F 147°F 149°F
Thickness 57°C 58°C 59°C 60°C 61°C 62°C 63°C 64°C 65°C
5 mm 2¼ hr 1¾ hr 1¼ hr 45 min 35 min 25 min 18 min 15 min 13 min
10 mm 2¼ hr 1¾ hr 1¼ hr 55 min 40 min 35 min 30 min 25 min 20 min
15 mm 2½ hr 1¾ hr 1½ hr 1¼ hr 50 min 45 min 40 min 35 min 30 min
20 mm 2¾ hr 2 hr 1¾ hr 1¼ hr 1¼ hr 55 min 50 min 45 min 40 min
25 mm 3 hr 2¼ hr 2 hr 1½ hr 1½ hr 1¼ hr 1¼ hr 60 min 55 min
30 mm 3¼ hr 2¾ hr 2¼ hr 2 hr 1¾ hr 1½ hr 1½ hr 1¼ hr 1¼ hr
35 mm 3¾ hr 3 hr 2½ hr 2¼ hr 2 hr 1¾ hr 1¾ hr 1½ hr 1½ hr
40 mm 4 hr 3¼ hr 2¾ hr 2½ hr 2¼ hr 2 hr 2 hr 1¾ hr 1¾ hr
45 mm 4½ hr 3¾ hr 3¼ hr 3 hr 2¾ hr 2½ hr 2¼ hr 2 hr 2 hr
50 mm 4¾ hr 4¼ hr 3¾ hr 3¼ hr 3 hr 2¾ hr 2½ hr 2½ hr 2¼ hr
55 mm 5¼ hr 4½ hr 4 hr 3¾ hr 3½ hr 3¼ hr 3 hr 2¾ hr 2¾ hr
60 mm 5¾ hr 5 hr 4½ hr 4¼ hr 3¾ hr 3½ hr 3¼ hr 3¼ hr 3 hr
65 mm 6¼ hr 5½ hr 5 hr 4½ hr 4¼ hr 4 hr 3¾ hr 3½ hr 3¼ hr
70 mm 7 hr 6 hr 5½ hr 5 hr 4¾ hr 4½ hr 4¼ hr 4 hr 3¾ hr
Pasteurization Time for Meat (Beef, Pork, and Lamb)
(starting at 41°F / 5°C and put in a 131–151°F / 55–66°C water bath)
55°C 56°C 57°C 58°C 59°C 60°C
Thickness 131°F 133°F 134.5°F 136.5°F 138°F 140°F
5 mm 2 hr 1¼ hr 60 min 45 min 40 min 30 min
10 mm 2 hr 1½ hr 1¼ hr 55 min 45 min 40 min
15 mm 2¼ hr 1¾ hr 1½ hr 1¼ hr 60 min 55 min
20 mm 2½ hr 2 hr 1¾ hr 1½ hr 1¼ hr 1¼ hr
25 mm 2¾ hr 2¼ hr 2 hr 1¾ hr 1½ hr 1½ hr
30 mm 3 hr 2½ hr 2 hr 2 hr 1¾ hr 1½ hr
35 mm 3¼ hr 2¾ hr 2¼ hr 2 hr 2 hr 1¾ hr
40 mm 3½ hr 3 hr 2½ hr 2¼ hr 2¼ hr 2 hr
45 mm 4 hr 3¼ hr 3 hr 2¾ hr 2½ hr 2¼ hr
50 mm 4½ hr 3¾ hr 3¼ hr 3 hr 2¾ hr 2½ hr
55 mm 5 hr 4¼ hr 3¾ hr 3½ hr 3 hr 3 hr
60 mm 5¼ hr 4¾ hr 4¼ hr 3¾ hr 3½ hr 3¼ hr
65 mm 6 hr 5¼ hr 4¾ hr 4¼ hr 4 hr 3¾ hr
70 mm 6½ hr 5¾ hr 5¼ hr 4¾ hr 4¼ hr 4 hr
61°C 62°C 63°C 64°C 65°C 66°C
Thickness 142°F 143.5°F 145.5°F 147°F 149°F 151°F
5 mm 25 min 25 min 18 min 16 min 14 min 13 min
10 mm 35 min 30 min 30 min 25 min 25 min 25 min
15 mm 50 min 45 min 40 min 40 min 35 min 35 min
20 mm 60 min 55 min 55 min 50 min 45 min 45 min
25 mm 1¼ hr 1¼ hr 1¼ hr 60 min 55 min 55 min
30 mm 1½ hr 1½ hr 1¼ hr 1¼ hr 1¼ hr 1¼ hr
35 mm 1¾ hr 1½ hr 1½ hr 1½ hr 1¼ hr 1¼ hr
40 mm 1¾ hr 1¾ hr 1¾ hr 1½ hr 1½ hr 1½ hr
45 mm 2¼ hr 2 hr 2 hr 1¾ hr 1¾ hr 1¾ hr
50 mm 2½ hr 2¼ hr 2¼ hr 2 hr 2 hr 2 hr
55 mm 2¾ hr 2¾ hr 2½ hr 2½ hr 2¼ hr 2¼ hr
60 mm 3 hr 3 hr 2¾ hr 2¾ hr 2½ hr 2½ hr
65 mm 3½ hr 3¼ hr 3¼ hr 3 hr 3 hr 2¾ hr
70 mm 3¾ hr 3¾ hr 3½ hr 3¼ hr 3¼ hr 3¼ hr